Group Title: Bulletin of the Florida Museum of Natural History
Title: Striated muscles of the black basses (Micropterus, Centrarchidae)
Full Citation
Permanent Link:
 Material Information
Title: Striated muscles of the black basses (Micropterus, Centrarchidae) myological stasis in a generalized group of percomorph fishes
Physical Description: p. 109-136 : ill. ; 28 cm.
Language: English
Creator: Borden, W. Calvin
Coburn, Miles M
Publisher: Florida Museum of Natural History, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008
Copyright Date: 2008
Subject: Black bass   ( lcsh )
Muscles   ( lcsh )
Centrarchidae   ( lcsh )
Genre: bibliography   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Abstract: Striated muscles of a generalized genus of percomorph fishes (Micropterus, Centrarchidae, Percomorpha) were described. Overall, myological variation was sparse among species of black bass. Variation took the form of minor variants in the size or shape of a muscle or of singular or incongruous variants characterized by abnormalities in a single specimen. The remaining mylogical variation occurred as mimicking variants and was shared irregularly among taxa. The lack of mylogical variation among black bass may well be correlated with the low degree of diversity exhibited in their ecology, life history, and external anatomy. However, the value of Micropterus in systematic and evolutionary studies is not compromised by morphological stasis. Instead, because Micropterus and other conserved lineages have been minimally responsive to ecological factors, they are valuable as outgroups to polarize character states, as identifiers of vicariant events leading to allopatric speciation, and as exemplars for studying the evolutionary mechanism of stabilizing selection. In addition, the description and assessment of mylogical variation in this generalized percomorph will be useful in future studies of comparative anatomy, functional morphology, and higher level systematics.
Statement of Responsibility: W. Calvin Borden and Miles M. Coburn.
Bibliography: Includes bibliographical references (p. 132-136).
General Note: Cover title.
General Note: Bulletin of the Florida Museum of Natural History; vol. 47, no. 4, pp. 109-136
 Record Information
Bibliographic ID: UF00101263
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 247939453
issn - 0071-6154 ;


This item has the following downloads:

PDF ( 9 MBs ) ( PDF )

Full Text


W. Calvin Borden' and Miles M. Cobum2


Striated muscles of a generalized genus of percomorph fishes (Micropterus, Centrarchidae, Percomorpha) were described. Overall, myological
variation was sparse among species of black bass. Variation took the form of minor variants in the size or shape of a muscle or of singular or
incongruous variants characterized by abnormalities in a single specimen. The remaining myological variation occurred as mimicking variants
and was shared irregularly among taxa. The lack of myological variation among black bass may well be correlated with the low degree of diversity
exhibited in their ecology, life history, and external anatomy. However, the value of Micropterus in systematic and evolutionary studies is not
compromised by morphological stasis. Instead, because Micropterus and other conserved lineages have been minimally responsive to ecological
factors, they are valuable as outgroups to polarize character states, as identifiers of vicariant events leading to allopatric speciation, and as
exemplars for studying the evolutionary mechanism of stabilizing selection. In addition, the description and assessment of myological variation
in this generalized percomorph will be useful in future studies of comparative anatomy, functional morphology, and higher level systematics.

Key Words: Black bass, Centrarchidae, Micropterus, Myology, Stasis.


In tro du action ......................................................................................................... 1 10
M e th o d s............................................................................................................ .. 1 1 0
M material Exam ined ..................................................... ...................................... 112
Results and M yological Descriptions....... .... ................... ..................... 112
M uscles of the C heek....................................... ............... ... ......... ........ .. 112
M uscles of the Ventral Surface of the Head............................... ................ 116
Muscles Serving the Dorsal Elements of the Branchial Arches...................117
Muscles Serving the Ventral Elements of the Branchial Arches................. 118
Muscles Between the Pectoral Girdle and the Skull, Hyoid, and Branchial
A rc h e s ..................................................................................... ....................... 12 0
M uscles of the Pectoral Fin....... .... ......................... 121
M uscles of the Pelvic Fin.................. ........................... 122
M uscles of the C audal F in ........................................ .................................. 126
Notes on Other Features of the Soft Anatomy in Micropterus species........ 128
D iscu ssio n ............................................................................................................ 12 9
M yological N otes.................................................. ...... ... ... ... ........... .. 129
M yological Variation....................................................... ................ 129
M acroevolutionary Patterns....... .... ............................................. 130
Phylogenetic U tility....................................................... ..... .............. 131
A cknow ledgem ents................................................................ ................ 132
L literature C ited...................... ................................................................. 132

'Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH 44115;
'Department of Biology, John Carroll University, University Heights, OH 44118;
Borden, W.C. and M.M. Coburn. 2008. Striated muscles of the black basses (Micropterus, Centrarchidae): Myological stasis in a generalized group of
percomorph fishes. Florida Museum. Nat. Hist. Bull. 47(4):109-136. [End of volume]

The myology of fishes is an under-described morpho-
logical system relative to osteology. This is unfortunate
because it has been shown to be relevant in determining
phylogenetic relationships across a variety of diverse
fish groups and taxonomic levels (e.g. tetradontiforms -
Winterbottom 1974b; acanthurids Winterbottom 1993;
teleosts Greenwood & Lauder 1981; cottoids Yabe
1985; cirrhitoids Greenwood 1995; acanthomorphs -
Mooi & Gill 1995; nasines Borden 1999; siluriform fami-
lies Diogo 2005; notothenioids Iwami 2004;
actinopterygians Springer & Johnson 2004; basal
acanthomorphs Wu & Shen 2004; bony fish and tetra-
pods Diogo & Abdala 2007). We initiated the current
study to (1) describe a relatively unknown character
system, striated muscles, in a generalized percomorph
genus, (2) evaluate the utility of myology in resolving
species level relationships among the black bass
(Micropterus, Centrarchidae), and (3) contribute to the
development of a myological data base suitable for higher
level systematic studies among percomorphs.
The phylogenetic affinities of Centrarchidae within
Percomorpha are unknown although centrarchids are
considered basal members of the order. The family is
monophyletic and consists of eight genera with 31 spe-
cies inhabiting freshwaters, mostly in eastern North
America, and known commonly as black bass, sunfish,
rock bass, and crappies (Nelson 2006). The genus
Micropterus Lacepede (1802) is monophyletic and is
comprised of seven species, the redeye bass (M.
coosae), the shoal bass (M cataractae), the Suwannee
bass (M notius), the Guadalupe (M treculii), and three
species which have recognizable subspecies: the small-
mouth bass (M. dolomieu: dolomieu and velox), the
spotted bass (M. punctulatus: henshalli and
punctulatus), and the largemouth bass (M. salmoides:
floridanus and salmoides). Black bass have been iden-
tified as the basal clade of centrarchids (Ramsey 1975;
Wainwright & Lauder 1992; Mabee 1993) or a derived
clade either as the sister group to Lepomis (Branson &
Moore 1962; Avise et al. 1977; Near et al. 2005), or
with unresolved affinities (Roe et al. 2002).
The interspecific relationships ofMicropterus spe-
cies have also varied considerably. Bailey (1938) and
Hubbs and Bailey (1940) envisioned two lineages of black
bass, one consisting solely ofM salmoides placed in
the genus Huro (Fig. lA). Branson and Moore (1962)
recognized six species and identified M salmoides as
the basal lineage based on a detailed analysis of the
acustico-lateralis system (Fig. iB). Ramsey (1975)
grouped seven species into three lineages with M
salmoides comprising one lineage, and M coosae and


M dolomieu comprising a second lineage (Fig. 1C).
These morphological hypotheses were followed by a
series of molecular analyses using phylogenetic meth-
ods (Fig ID, Johnson et al. 2001; Fig. 1E, Kassler et al.
2002; Fig. IF, Near et al. 2003, 2005). While the results
of the Johnson et al. (2001) study resembled those mor-
phological hypotheses with M salmoides as the basal
clade, the remaining molecular studies suggested new
phylogenetic relationships. Kassler et al. (2002), em-
ploying meristic and molecular characters, recoveredM
salmoides deeply nested in the tree and a non-sister
group relationship between M punctulatus henshalli
and M punctulatus punctulatus (Fig. 1E). Most re-
cently, Near et al. (2003, 2005) recovered a fully re-
solved tree supporting a M. dolomieu-M. punctulatus
clade as the sister group to the remaining black bass
(Fig. IF).
Black bass are high trophic level predators prima-
rily of fishes and crayfishes (Scott & Crossman 1973;
Koppelman & Garrett 2002) and well known as sport
fishes. As a consequence, numerous studies have in-
vestigated facets of their ecology, reproduction, life his-
tory, and behavior (see Philipp & Ridgway 2002 as a
starting point). In addition, various anatomical compo-
nents have been described as exemplars in the context
of functional morphology (Wainwright & Lauder 1992;
Higham 2007), kinematics (Lauder 1982), ecomorphology
(Norton & Brainerd 1993; Wintzer & Motta 2005), de-
scriptive osteology (Shufeldt 1900; Blair & Brown 1961;
Mabee 1988), ontogeny (Mabee 1993), and pigment
patterns (Mabee 1995). A complete morphological ap-
praisal of a relatively conservative anatomical system
(i.e. myology) promotes a fuller understanding of the
comparative anatomy, functional morphology, and sys-
tematics of these fishes.

Sample size can adversely affect phylogenetic results
particularly if character state variation within the taxo-
nomic unit is not identified. A protocol for detecting
myological variants was put forth by Raikow et al. (1990)
and subsequently modified by Kesner (1994). Their
models suggested that at least 10 specimens of a refer-
ence species should be bilaterally dissected in a search
for variable character states. Variants were catego-
rized as "incongruous" (abnormal and nonfunctional
variation due to a malformation), "mimicking" (an atypi-
cal condition in one species that is typical for a different
species), "minor" (slight variation in size, shape, position
and perhaps resulting from nonbiological causes), and
"singular" (atypical but not nonfunctional, and not present
in other taxa) (Raikow et al. 1990). Incongruous, minor,

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

dolomieu coosae notius treculii punctulatus

coosae + dolomieu





salmoides -

cataractae + notius
+ punctulatus + treculii

- dolomieu

-~) 0
0 0 -
0 0
.( -8 = 6- (
"5 "= 3
.o X 8 S ,- =

/) h0)
=3 cc <
V C .- (D i
o (0 = U) Ca (
" o a t- o n
ci 2 .3 0 .


Figure 1. Proposed phylogenetic relationships among the black bass. Each hypothesis is based on a different data set
and tree building criterion, if any. A. Hubbs and Bailey (1940, Fig. 1). "dolomieu" and "velox" are subspecies ofM
dolomieu. "henshalli", "punctulatus", and "wichitae" are subspecies of M punctulatus. B. Branson and Moore
(1962, Fig. 15). C. Ramsey (1975) included 2 subspecies in M salmoides and M dolomieu each and 3 subspecies
in M punctulatus. D. Johnson et al. (2001, Fig. 2). E. Kassler et al. (2002, Fig. 6). F. Near et al. (2005, Fig. 7). Near
et al (2003) switched the position of "cataractae" and "coosae". The numbers located at each node are age esti-
mates in "millions of years ago" using a fossil cross-validation methodology (Near et al. 2005).

and singular variants are phylogenetically uninformative;
mimicking variants create homoplasies in the form of
convergences or parallelisms. Raikow et al. (1990) rec-
ommended initial dissections of a reference species to
identify and eliminate minor and incongruous variants.
Single bilateral dissection and at least two unilateral dis-
sections should be undertaken in the remaining species

to resolve mimicking and singular variants. Alternatively,
in the absence of 10 specimens for a given species, four
to five specimens of several species should be dissected
(Kesner 1994).
Lacking a series of 10 specimens, M. coosae, M
d. dolomieu, and M s. salmoides were dissected for
seven, five, and eight specimens respectively of which




four, four, and six specimens were bilaterally dissected.
In all specimens examined, muscles of the branchial and
hyoid arches, pectoral, pelvic, and caudal fins were bi-
laterally dissected. Muscles of head, cheek, jaws, sus-
pensorium, and those connecting any two components
of the head, suspensorium, and fins were dissected bi-
laterally in at least one specimen. Specimens were dis-
sected sequentially and in random order excepting most
specimens of M d. dolomieu and M s. salmoides,
which were dissected at the beginning of the study to
assess the prevalence of the four variant classes.
Striated muscle terminology follows Winterbottom
(1974a); nerves follow Freihofer (1963). Muscle de-
scriptions represent a consensus or generalized form of
each species, thus averaging out the effects of minor
variation such as muscle proportions or muscle origins
on bones with fimbricate sutures (e.g. prootic and pterotic
suture). Swimbladder and subcutaneous muscles were
not observed, median fin and eye muscles were not ex-
amined, and body and cardinal muscles were not described
in detail except as relevant to muscles described below.
Roman numerals were used to denote muscles; Arabic
numbers were used to denote bones. Singular and in-
congruous variants were noted under the appropriate
muscle and checked against antimeres and other speci-
mens. Intraspecific and mimicking variation is listed in
Table 1. Soft anatomical features such as the number
and structure of pyloric caecae and the nasal rosette
were also described. Morphological conditions in
outgroup species were described for characters vari-
able only among Micropterus species or for incongru-
ous and singular variants.
Fish were fixed in 10% formalin and stored in 70-
75% ethyl alcohol. Specimens were dissected using a
Nikon SMZ-U microscope and drawn using a camera
lucida attachment on a Leica MZ 125 microscope. Small
and questionable muscle fibers were stained with a modi-
fied iodine solution (Bock & Shear 1972) to highlight
them against non-muscle tissue. Following dissection,
some specimens were cleared and double stained for
bone alizarinn red-S) and cartilage (Alcian blue) using
modified protocols of Potthoff (1984) and Taylor and
Van Dyke (1985).
Scientific names follow Nelson et al. (2004) with
the following additions that recognized subspecific sta-
tus in M. dolomieu [dolomieu and velox], M.
punctulatus [henshalli and punctulatus] (following
Hubbs & Bailey 1940), and M. salmoides floridanuss
and salmoides] (following Bailey & Hubbs 1949). Al-
though Kassler et al. (2002) argued for the promotion of
M s. floridanus and M s. salmoides to specific status
based on meristic and molecular data, we retain them as


subspecies following the recommendation of Nelson et
al. (2004) for additional analysis.

Institutional abbreviations follow Leviton et al. (1985).
The number of specimens dissected and their standard
lengths) in millimeters follows the catalog number.
Micropterus. (1): M cataractae Williams &
Burgess 1999, ROM 82445, 1 (216.2 mm SL); UMMZ
168752, 1 (102.8 mm SL). (2): M coosae Hubbs &
Bailey 1940, OSUM 105229, 1 (104.3 mm SL); ROM
82449, 1 (116.0 mm SL); ROM 82450, 1 (126.1 mm
SL); UF 86268, 1 (131.8 mm SL); UF 86313, 1 (122.2
mm SL); UF 89989, 1 (154.7 mm SL); USNM 168075,
1 (98.7 mm SL). (3): M d. dolomieu Lacepede 1802,
CAS 13020 C&S, 1 (77.2 mm SL); OSUM 102599, 1
(173.2 mm SL); OSUM 102600,1 (155.2 mm SL); ROM
1783CS, 1 (178.3 mm SL); ROM 82436, 1 (248.8 mm
SL); ROM 82437, 1 (133.2 mm SL). (4): M d. velox
Hubbs & Bailey 1940, UMMZ 116802, 1 (121.6 mm
SL); UMMZ 128680, 1 (120.7 mm SL). (5): M notius
Bailey & Hubbs 1949, UF 57323, 1 (187.6 mm SL); UF
58761, 2 (131.8 145.2 mm SL, fish labeled "4" and "5"
respectively by UF); TU 9775, 2 (107.4 152.3 mm
SL). (6): M p. henshalli Hubbs & Bailey 1940, UAIC
10587.15, 1 (154.3 mm SL); UAIC 12652.19, 1 (132.8
mm SL). (7): M p. punctulatus (Rafinesque 1819),
OSUM 102597, 1 (153.4 mm SL); OSUM 102598, 1
(144.7 mm SL); USNM 251991, 2 (88.0 95.4 mm SL).
(8): M s. floridanus (Lesueur 1822), UMMZ 158634,
1 (128.8 mm SL); UMMZ 163350, 1 (125.6 mm SL).
(9): M s. salmoides (Lacepede 1802), CAS 19030
C&S, 1 (60.6 mm SL); ROM 1780CS, 1 (170. mm SL);
ROM 1781CS, 1 (159.1 mm SL); ROM 1782CS, 1 (138.2
mm SL); ROM 82435, 1 (176.5 mm SL); ROM 82446,
4 (153.2 219.4 mm SL). (10): M treculii (Vaillant &
Bocourt 1874), OSUM 105227, 1 (254.0 mm SL); ROM
1784CS, 1 (253.0 mm SL); UMMZ 136849, 1 (112.8
mm SL); UMMZ 220247, 1 (137.2 mm SL).
Centrarchids. (1): Ambloplites ariommus
Viosca 1936, ROM 82444, 1 (105.2 mm SL). (2):
Centrarchus macropterus (Lacepede 1801), UMMZ
164961, 1 (124.8 mm SL). (3): Lepomis cyanellus
Rafinesque 1819, ROM 82438, 1 (81.1 mm SL). (4):
Lepomis gibbosus (Linnaeus 1758), ROM 82439, 1
(113.6 mm SL). (5): Pomoxis nigromaculatus (Lesueur
1829), ROM 82440, 1 (152.3 mm SL).

The ligamentum primordium attaches tendinously

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

on the dorsolateral surface of the maxilla and arcs pos-
teriorly and ventrally to attach on the lateral surface of
the angular (angulo-articular) anterior of the quadrate-
angular articulation.
Adductor mandibulae (A], A2, A3, Azi, Figs.
2-5, 8). All sections of the adductor mandibulae are
graded to varying degrees, and the extensive grading
complicates assignment of fibers to a specific section.
After removal of the skin and infraorbitals, the adductor
mandibulae occupies the lateral side of the suspenso-
rium in the space bounded by the orbit, preopercle, and
jaws. The lateralmost section of the adductor mandibulae
is Al. Section Al is described as two bundles of un-
equal size. The dorsalmost of the two sections origi-
nates on the preopercle, anterodorsal face of the
hyomandibula, and base of the elevator arcus palatini.
The ventral border is separable from the ventral and
main mass ofA1 only laterally as fibers are graded me-
dially. As the dorsal section passes anteriorly, it rolls
medially over the main mass of Al and grades into a
medial aponeurosis shared by several sections of the
adductor mandibulae. Fibers of the main bundle of Al
originate primarily on the preopercle but also include the
hyomandibula. Insertion includes the ligamentum pri-
mordium particularly at the anterodorsal comer of the
muscle and the aforementioned medial aponeurosis. In
addition, a well-developed tendon arises from the




DOp LPect

/ /


Figure 2. Left, lateral view of the superficial cheek
musclulature ofM p. henshalli (UAIC 12652.19, 132.8
mm SL). Anterior is to the left. Scale bar = 5 mm.
Abbreviations: Al, A2, A3 sections of the adductor
mandibulae; AAP adductor arcus palatine; DOp di-
latator operculi; LAP elevator arcus palatini; LOp -
levator operculi; lp ligamentum primordium; LPect -
levator pectoralis; RMV ramus mandibularis V.

anteromedial comer of the muscle mass, runs parallel to
the ligamentum primordium, and inserts on the medial
surface of the maxilla at the level of the ligamentum
primordium. Insertion on the medial surface ofthe max-
illa suggests that it is Ald; however, the lack of a dis-
tinct origin from the palatal arch or suspensorium and its
dorsolateral position relative to A2 preclude its identifi-
cation as A la.
A2 originates on the preopercle and hyomandibula
and is inseparable from Al due to extensive grading.
Minor grooves and lateral separations were occasion-
ally present in the fused A 1- A2a bundle, but disappeared
medially due to extensive grading and, therefore, were
not given subsection status. Anterior and more dorsal
fibers of A2 grade into the medial aponeurosis shared
by the bundles of Al while more ventral fibers grade
into AM via a myocommatum. A tendon arises from the
anteroventral comer of the Al- A2 muscle mass and
inserts on the medial side of the angular in the Meckelian
fossa ventral to the cartilage.
Ramus mandibularis V of the 5th cranial nerve
(trigeminal nerve) is medial to Al- A2 and lateral to a
single section of muscle identified as A3. A3 originates
on the quadrate, symplectic, hyomandibula, preopercle,
metapterygoid, and base of the elevator arcus palatini at
the metapterygoid. The posterior border ofA3 is notched
weakly giving it a chevron shape. Dorsal fibers of A3
attach to the tendon of Al-A2, the shared medial apo-
neurosis, and Ai More ventral fibers ofA3, originat-
ing on the quadrate and symplectic, run near horizontal
and give rise to a tendon that inserts on the medial side
of the angular in the Meckelian fossa dorsal to the car-
tilage and near its posterior end. This tendon is lateral to
the tendon from A l-A2.
Ai attaches on the medial side of the lower jaw
from the intermandibularis at its anterior end and ex-
tends posteriorly via a strong tendon to originate on the
quadrate, preopercle, and symplectic. The tendon of
Ai is medial to the tendons from sections Al-A2 and
A3; however, fibers of Ai are heavily graded with both
tendons and determining which fiber belongs to which
section is both frustrating and fruitless as this pattern is
consistent among Micropterus species.
Levator arcus palatini (LAP, Figs. 2, 3, 7). This
muscle is a large bundle forming the posterior wall of
the orbit. It originates on the sphenotic and fans out
onto the metapterygoid and hyomandibula with a few
fibers extending to the adductor arcus palatini. The ori-
gin does not appear to include the frontal dorsally or
prootic medially. The posterior border passes medial to
the anterior border of the dilatator operculi, but the two
muscles have only a few, if any, graded fibers.


ligament from



Figure 3. Left, lateral view of the superficial cheek musculature ofMM cataractae (UMMZ 168752, 102.8 mm SL).
Anterior is to the left. A. as above. Scale bar = 5 mm. B. Detailed view of the tendons inserting on the medial side of
the maxilla and fibers passing to the medial side of the lower jaw. Scale bar = 1 mm. Abbreviations as in Figure 2.


Al-A2 tendon
A1-A2 to medial face
of maxilla

Al-A2 tendon
to medial face
of maxilla

/ )

Am tendon to preopercle
A2 tendon

A2 tendon

Figure 4. Medial view of the cheek musculature of M p. henshalli (UAIC 12652.19, 132.8 mm SL). Anterior is to
the right. Scale bar = 5 mm. A. The lower jaw has been removed, and the tendon of At to the suspensorium and
preopercle has been cut. B. As above with A6 removed and most ofA3 cut and removed. Abbreviations: A6 medial
section of the adductor mandibulae; as in Figure 2.


BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)






' 1 HyoAdd

Figure 5. Medial view of the muscles connecting the
cranium to the right suspensorium and opercular series
of M s. floridanus (UMMZ 163350, 125.6 mm SL).
Anterior is to the left. Scale bar = 5 mm. Abbreviations:
AddHy adductor hyomandibulae; AddOp adductor
operculi; HyoAdd hyohyoides adductores; i site of
interhyal articulation; as in Figures 2 and 4.

Dilatator operculi (DOp, Figs. 2, 3, 6, 7). This
muscle has the shape of an inverted triangle with a broad
origin on the sphenotic, pterotic, and hyomandibula. It
tapers ventrally and inserts on the dilatator process of
the opercle. Fibers pass medial to the dorsal tip of the
preopercle. The posterior border is medial to the leva-
tor operculi; fibers of the two muscles are not graded.
Levator operculi (LOp, Figs. 2, 5-7). The origin
is confined to the pterotic but the muscle quickly fans
out onto the medial, dorsal surface of the opercle. A
small, autonomous section of fibers originates from the
posttemporal and inserts on the medial, dorsal surface
of the opercle posterior to the main mass. This poste-
rior section is weakly developed and lies within connec-
tive tissue running from the skull to the opercle. This
posterior section was the most diffuse and smallest in
both specimens of M. cataractae, and absent in
Lepomis cyanellus (ROM 82438).
Adductor arcus palatini (AAP, Figs. 2, 3, 5).
This muscle forms the posterior half of the orbit floor. It
originates on the prootic and parasphenoid and inserts
on the metapterygoid and mesopterygoid. Posteriorly it
is continuous and graded heavily with the adductor
Adductor hyomandibulae (AddHy, Figs. 5, 7).
This muscle is continuous with the posterior border of
the adductor arcus palatini. It inserts solely on the me-
dial side of the hyomandibula. The origin includes the
prootic, pterotic, and anteriodorsal comer of the intercalar.

Figure 6. Left, lateral view of the posterior muscles con-
necting the cranium and opercular series of M p.
punctulatus (OSUM 102598, 144.7 mm SL). Anterior
is to the left. Scale bar = 5 mm. Abbreviations as in
Figure 2.

DOp AddOp
LAP h AddHy / LOp




Epx LPect

Yd 7

2 ':
ii': !i


Figure 7. Left, lateral view of muscles connecting the
cranium to the suspensorium and pectoral girdle and the
dorsal muscles of the branchial gill arches of M p.
punctulatus (OSUM 102598, 144.7 mm SL). Anterior
is to the left. Scale bar = 5 mm. Abbreviations: Epx -
epaxialis; h site of hyomandibular articulation; LE -
levator extemus; LI elevator intemus; LPost elevator
posterior; OD obliquus dorsalis; PrPect protractor
pectoralis; TD transverses dorsalis; as in Figures 2
and 5.



The origin is linear on the neurocranium (sphenotic-
pterotic) along the medial side of the hyomandibula's
articulation with the skull. The muscle is bulkier on ei-
ther side of this articulation.
Adductor operculi (AddOp, Figs. 5, 7). The ad-
ductor operculi originates on the intercalar and extends
ventrally to the suture with the exoccipital but not onto
the exoccipital. The origin lies posterior to the adductor
hyomandibulae and anterior to the elevator posterior. The
adductor operculi is separable from the latter but may
grade with the adductor hyomandibulae. Insertion is on
the medial side of the opercle dorsal to a horizontal bony
ridge, and posterior to the opercle-hyomandibula articu-
lation and elevator operculi.

Intermandibularis (IntM, Fig. 8). The
intermandibularis originates on the medial surface of the
dentary, on either side of the symphysis, and meets its
antimere at the ventral midline in the absence of a raphe.
The muscle is a flattened sheet lying in a frontal plane.
Protractor hyoidei (PrHy, Fig. 8). The anterior
border of this muscle is bifurcated to accommodate its
origin on the medial surface of the dentary above and
below the intermandibularis. Anteriorly the antimeres
are held together along the ventral midline via a septum
but diverge posteriorly. Two myocommata are present
posteriorly. Insertion is on the lateral side of the anterior
ceratohyal with the posteroventral fibers passing later-
ally to branchiostegal rays 1 and 2, but medially to ray 3.
An exception to this pattern wasM. coosae (UF 86313),
in which the right antimere passes lateral to
branchiostegal rays 1-3 and medial to ray 4; however,
the left antimere follows the "normal" pattern. It may
be more accurate to note that the protractor hyoidei
passes medial to the first branchiostegal ray having a
well-developed head (usually the third ray) that also ar-
ticulates on the lateral side of the anterior ceratohyal.
Branchiostegal rays anterior to this ray lack such well-
developed heads and abut the ventral edge of the ante-
rior ceratohyal, not its lateral surface.
Hyohyoides inferioris. This muscle running from
the urohyal to the hyoid arch is absent.
Hyohyoidei adductores (HyoAdd, Fig. 9). The
adductor bundles originate primarily on the medial side
of the opercle and insert on the dorsoposterior surfaces
of the posteriormost branchiostegal rays. Additional
bundles are isolated distally between branchiostegal rays.
In general, adductor fibers parallel the ventral borders
of the anterior and posterior ceratohyals.

" >PrHy


Figure 8. A. Dorsal and B. ventral view of the lower
jaws and of M coosae (ROM 82449, 116.0 mm SL).
Anterior is to the left. Unfilled area ofA is toothed. Scale
bar = 5 mm. Abbreviations: IntM intermandibularis;
PrHy protractor hyoidei; as in Figure 4.


Figure 9. Right, lateral view of the hyoid arch minus the
urohyal of M d. dolomieu (OSUM 102600, 155.2 mm
SL). Anterior is to the right. Scale bar = 5mm. The
branchiostegals have been spread and not all fibers of
the hyohyoidei abductores were drawn including the
antimere originating from the hypohyals. Abbreviations:
HyoAbd hyohyoideus abductores; as in Figure 5.

Hyohyoidei abductores (HyoAbd, Fig. 9). The
abductors are composed of many isolated bundles. The
largest bundle originates tendinously on the dorsal and
ventral hypohyals. This bundle crosses the midventral
line and attaches to the medial surfaces of branchiostegal
rays 1 and 2. Antimeres overlap at the origin with the
left antimere (left side of hypohyals to right
branchiostegal rays) ventral to the right antimere. Addi-
tional bundles originate muscularly on the ventral side of
the anterior ceratohyal and insert on the medial, proxi-
mal surfaces of adjacent branchiostegal rays. In gen-
eral, abductor bundles are orientated obliquely relative
to the ventral borders of the anterior and posterior

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

LE LPost




Figure 10. Dorsal view of the branchial gill arch muscles
of M p. henshalli (UAIC 12652.19, 132.8 mm SL).
Anterior is to the left. Scale bar = 5 mm. The left
epibranchial 1 has been removed as has the right
pharyngobranchial 1. The right antimere of the retrac-
tor dorsalis, obliquus dorsalis III/IV, and transversus dor-
salis IV have been removed. Abbreviations: Add ad-
ductor; OP obliquus posterior; RD retractor dorsa-
lis; SphOes sphincter oesophagi; as in Figure 7.

Levatores externi (LE I-IV, Figs. 7, 10, 11). Four
muscles, each a elevator extemus, constitute the leva-
tores extemi with each bundle serving the dorsal ele-
ments of one of the first four gill arches. Levatores
extemi I and II originate primarily on the prootic while
III and IV originate primarily on the pterotic although all
four muscles probably share both the prootic and pterotic.
Levator extemus I is nearly vertical but the remaining
extemi muscles are orientated obliquely. Levatores
extemi III and IV are closely appressed but not graded.
Levator extemus I inserts on epibranchial 1 anterolat-
eral to its articulation with the interarcual cartilage.
Levator extemus II inserts on a raised dorsoposterior
ridge of epibranchial 2; elevator extemus III inserts on a
well developed uncinate process of epibranchial 3, and
elevator externus IV inserts on a raised ridge of
epibranchial 4 that is lateral to the uncinate process but
medial to a very small elevator process. Insertion sites
move distally from elevator extemus I to IV.
Levatores intern (LI II-III, Figs. 7, 10). Two
muscles, each a elevator intemus, serve the dorsal ele-


Add IV
Add IV

Add V

Figure 11. Posterior view of the left fourth and fifth bran-
chial gill arches and muscles of M d. velox (UMMZ
128680, 120.7 mm SL). The esophagus is to the right.
Scale bar = 1 mm. The sphincter oesophagi grades into
the obliquus posterior medially. The protractor pectora-
lis has been removed. Muscle fibers extend ventrally to
the level of the epibranchial-ceratobranchial articulation
before grading into the branchial wall. The latter is at-
tached to the posterior surfaces of epibranchial 4 and
ceratobranchials 4 and 5. Abbreviations: cb 4 -
ceratobranchial 4; cb 5 ceratobranchial 5; eb 4 -
epibranchial 4; as in Figures 7 and 10.

ments of either the second or third gill arch. They origi-
nate on the prootic and pterotic medial to the levatores
extemi. Levator intemus II is medial to III, and they
form an "X" in lateral view. Levator intemus II inserts
on the dorsal surface of pharyngobranchial 2 adjacent
SphOes to its articulation with the interarcual cartilage. Levator
interns II inserts on the dorsal surface of
pharyngobranchial 3 adjacent to its articulation with
epibranchial 3. InM. treculii (UMMZ 136849), fibers
of elevator intemus III also insert on the cartilaginous
end of epibranchial 3 at its articulation with
pharyngobranchial 3.
- ADD IV Levator posterior (LPost, Figs. 7, 10). The leva-
tor posterior is well developed and separated from the
extemi and intemi muscles. It originates on the intercalar,
posterior of the adductor operculi, at the base of the
'stump' that articulates with the posttemporal. It inserts

on the dorsal, distal surface of epibranchial 4 anterior to
elevator extemus IV.
Obliquus dorsalis (OD III IV, Figs. 7, 10). A
single bundle originates from the dorsal surfaces of
epibranchials 3 and 4 and extends medially to insert on
the dorsal surface of pharyngobranchial 3. Fibers along
the epibranchials are heavily graded.
Transversi dorsales (TD II, IIl/IV, Figs. 7, 10).
Transversus dorsalis II consists of two graded bundles.
An anterior circular bundle arises from the dorsolateral
surface of pharyngobranchial 2 and passes medially
where it attaches to its antimere via a raph6. A more
posterior bundle arises along the dorsal surface of
epibranchial 2 and passes to the dorsal midline where it
attaches to its antimere via a raph6. The posterior bor-
der of the circular section is dorsal to the more posterior
section but the two sections are heavily graded. Ven-
trally the bundles adhere to the dorsal side of the skin
lining the buccal cavity along the dorsal midline. Dor-
sally, the muscle abuts the parasphenoid. Springer and
Johnson (2004) noted a small accessory cartilage on the
anterodorsal tip of pb2 as part of the origin of TD II in
cleared and stained material of M. dolomieu. In es-
sence, this cartilage lies on the "free" and cartilaginous
end of pb2 adjacent to the interarcual cartilage. Such a
cartilage was not observed during the dissection of the
dorsal gill arches prior to double-staining. Eight speci-
mens were cleared and stained (one each ofM. coosae,
M. d. dolomieu, M. notius, M. p. punctulatus, M.
treculii, and three M s. salmoides) following dissec-
tion. The first author noticed what he would call a car-
tilaginous bud on one specimen ofM d. dolomieu and
M s. salmoides. However, confidence in this interpre-
tation is not high since the TD II and/or pb's were re-
moved in many dissections and consequently could have
removed any autogenous or bud-like cartilages.
A transversus dorsalis III/IV bundle originates on
the dorsal surfaces of epibranchial 3 and
pharyngobranchial 3 and often includes the medial carti-
laginous end of epibranchial 4 and dorsal surface of
pharyngobranchial 4. Fibers extend medially to join its
antimere in the absence of a raph6. The posterior bor-
der of the bundle is usually separable from fibers of the
sphincter oesophagi.
Obliquus posterior (OP, Figs. 10-11). This is a
well-developed muscle posterior to both of the adductor
muscles. It is attached to the posterior side of
ceratobranchial 5 and runs dorsally to insert on the pos-
terior surface of epibranchial 4, medial to elevator extemus
IV. The obliquus posterior grades into the sphincter oe-
sophagi medially.
Adductores (Add IV-V, Figs. 10, 11). Adductor


IV connects ceratobranchial 4 and epibranchial 4. The
insertion on epibranchial 4 is lateral to the obliquus pos-
terior. Adductor V connects ceratobranchials 4 and 5;
however, fibers may extend onto the cartilaginous end
of epibranchial 4 at its articulation with ceratobranchial
4. Adductor V is posterior to adductor IV.
Retractor dorsalis (RD, Fig. 10). The retractor
dorsalis is a large muscle originating on the ventral sur-
faces of vertebral centra 2 and 3, with some fibers on
the posterior half of vertebral centrum 1. The left and
right muscles pass anteroventrally to insert on the dorsal
surfaces of pharyngobranchials 3 and 4.
Interbranchiales abductors. The abductors con-
nect the proximal, lateral bases of the filaments to the
bony arches.
Interbranchiales adductores (IntBAdd, Fig.
12). These bundles originate on the base of the gill fila-
ment of one hemibranch and attach distally to the gill
filament of the opposite hemibranch. Thus, this is a Type
I adductor as defined by Pasztor and Kleerekoper (1962).

The ventral side of the branchial arches is charac-
terized by a distinct pattern of ligaments connecting the
bony elements. From the ventral surface ofbasibranchial
3 a cupula (cartilaginous pedicle) arises and is positioned
between the fourth ceratobranchials. An U-shape liga-
ment connects the cupula posteriorly to each of the pro-
cesses on the ventral surfaces of the third hypobranchials.
This semi-circular ligament was originally considered to
be characteristic of acanthopterygians (Dietz 1914, as
cited by Winterbottom 1974a; Stiassny 1992), but has
been identified in several non-acanthopterygians (Springer
& Johnson 2004). Additional ligaments connect
hypobranchials 2 and 3. The ventral aorta ascends and
passes just anterior to the cartilaginous pedicle.
Sphincter oesophagi (SphOes, Figs. 10-11, 13).
This muscle is comprised of many autonomous bundles
and fibers. Perhaps the most obvious bundles circum-
scribe the esophagus. In doing so, they may grade with
the obliquus posterior. Fibers also parallel the posterior
borders of transversus dorsalis III/IV and transversus
ventralis V and may grade with either muscle. One
sphincter bundle holds the retractor dorsalis against the
esophagus acting as a 'belt'. Additional sphincter bundles
lie medially and laterally to the retractor dorsalis as the
fibers run from the esophagus to the dorsal side of
pharyngobranchial 3.
Obliqui ventrales (OV I-III, Fig. 13). Three
obliquus ventralis muscles connect the ceratobranchials
with their respective hypobranchials across their ventral

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

mediately posterior to transversus ventralis IV. M.
treculii (ROM 1784CS) possesses an extra bundle of
rectus ventralis IV originating on the left ceratobranchial
4 and inserting on the U-ligament. Centrarchus
macropterus (UMMZ 164961) also has an additional
rectus bundle originating on ceratobranchial 4, passes
ventral to transversus ventralis IV, and inserts tendinously
on the posterior side of the cupula at its base.
Transversi ventrales (TV IV-V, Fig. 13). Trans-
versus ventralis IV connects the medial surfaces of
ceratobranchials 4 across the midline in the absence of
a raphe. The posterior border is ventral to the anterior
border of transversus ventralis V. Transversus ventralis
V connects the fifth ceratobranchials in a similar man-
ner. The posterior border of transversus ventralis V is
continuous with sphincter oesophagi with some fibers
appearing to grade with it. Dorsally, the transversi
ventrales attach to skin between the ceratobranchials.
Rectus communis (RComm, Fig. 13). Antimeres
insert on the lateral surfaces of the urohyal and are graded
above its dorsal edge. Antimeres diverge posteriorly
and pass medially to ligaments connecting the urohyal
and hypobranchials 2 and 3. They insert tendinously on
the ventrolateral edges of the fifth ceratobranchials, lat-


Figure 12. Dorsal view of a gill filament from the trans-
verse section of the left, ceratobranchial 3 of M p.
punctulatus (OSUM 102598, 144.7 mm SL). Anterior
is to the left. Scale bar = 1 mm. The interbranchiales
abductores were not included but would connect either
side of the ceratobranchial to the bases of the gill fila-
ments. Abbreviations: IntBAdd interbranchialis ad-
ductor; as in Figure 11.

surfaces. The majority of each muscle lies on the
hypobranchials while the ceratobranchials contain strong
tendinous attachments. Some fibers ofobliquus ventra-
lis III also attach to the U-ligament. By definition, these
latter fibers comprise rectus ventralis III, and the result-
ing bundle is a graded obliquus ventralis III and rectus
ventralis III.
Recti ventrales (RVIV, Fig. 13). A single rectus
ventralis IV connects the ventral side of ceratobranchial
4 to the U-ligament. Antimeres converge slightly to-
ward the ligament. A fascia extends dorsally along the
margins of rectus ventralis IV and the rectus communis
forming a longitudinal branchial wall. This fascia ex-
tends posteriorly and attaches to ceratobranchial 5 im-


Figure 13. Ventral view of the branchial gill arch muscu-
lature of M d. dolomieu (OSUM 102600, 155.2 mm
SL). Anterior is to the left. Scale bar = 5 mm. The hyoid
arch has been removed and the rectus communis cut
away from the urohyal. The right antimere of the rec-
tus communis has been cut near its insertion. Abbrevia-
tions: hb hypobranchial; OV obliquus ventralis; PCE
- pharyngoclavicularis externus; PCI -
pharyngoclavicularis internmus; RComm rectus com-
munis; RV rectus ventralis; TV transverses ventra-


eral to the insertions of pharyngoclavicularis extemus
and intemus. The rectus communis may become tendi-
nous as it passes lateral to the ventral aorta.

Sternohyoideus (StHyo, Figs. 8, 14-15). The
stemohyoideus originates on the dorsal surface of the
ventral arm of the cleithrum, lateral and anterior to the
origin of pharyngoclavicularis extemus. Antimeres are
heavily graded and contain three myocommata. The
bundles pass anteriorly and insert on the lateral sides of
the urohyal. Connective tissue from the stemohyoideus
extends dorsally and attaches to the ventral processes
ofhypobranchials 2 and 3. The stemobranchialis, which
is derived from the stemohyoideus and attaches to the
third hypobranchial, is absent.
Pharyngoclavicularis externus (PCE, Figs. 13-
15). This muscle originates on the dorsal surface of the
ventral arm of the cleithrum. It passes vertically to in-

StHyo /

A /


Figure 14. Left, lateral view of the pectoral fin (15 rays)
and girdle of M treculii (UMMZ 220247, 137.2 mm
SL). Anterior is to the left. Scale bar = 5 mm. A. Super-
ficial abductor muscles and those attaching to the
cleithrum from the branchial and hyoid arches. B. Me-
dial abductor muscles. Abbreviations: AbdP abductor
profundus; AbdS abductor superficialis; ArrV ar-
rector ventralis; cl cleithrum; StHyo stemohyoideus;
as in Figure 13.

AddS-1 /

I ddM

AddP cr ArrD

AddP cr ArrD


Figure 15. Left, medial view of the pectoral fin (15 rays)
and girdle of M treculii (UMMZ 220247, 137.2 mm
SL). Anterior is to the right. Scale bar = 5 mm. A. As
above. B. After removal of the adductor superficialis
bundles. The adductor radialis is outlined by the dashed
line. Abbreviations: AddM adductor medialis; AddP -
adductor profundus; AddRad adductor radialis; AddS
- adductor superficialis; ArrD arrector dorsalis; cr -
coracoid; as in Figures 13 15.

sert tendinously on the ventral side of ceratobranchial 5.
Length of its insertion is almost that oftransversus ven-
tralis V.
Pharyngoclavicularis internus (PCI, Figs. 13-
15). This muscle originates on the medial surface of the
cleithrum near the 'bend' at the juncture of the dorsal
and ventral arms. The bundle passes horizontally to in-
sert tendinously on the ventral side of ceratobranchial 5,
medial to the pharyngoclavicularis extemus. The inser-
tion occupies a small area near the posterior border of
transversus ventralis V. Pomoxis nigromaculatus
(ROM 82440) is unique in that the anterior portions of
both antimeres continue anteriorly and insert tendinously
on the tips of ceratobranchial 5. In doing so, this ante-
rior extension passes dorsal to transversus ventralis IV.
Protractor pectoralis (PrPect, Fig. 7). This is a
well-developed muscle posterior to the muscles serving
the dorsal elements of the branchial arches. It origi-
nates tendinously on the wing of the pterotic and passes
ventrally where it grades into the branchial wall. At the
point where muscle fibers disappear, the branchial wall
attaches strongly to the cleithrum, dorsal to
pharyngoclavicularis intemus and ceratobranchial 4.

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)



AbdP r17


Figure 16. Different patterns of the origin and insertion
of the adductor radialis of the pectoral fin. Pectoral
rays served have been numbered with the leading ray
as ray 1. Scale bar = 1 mm. A. Medial view of the left
pectoral fin (16 rays) ofM notius (TU 9775, 107.4 mm
SL) after removal of the adductor muscles. Anterior is
to the right. B. Medial view of the left pectoral fin (17
rays) ofM. notius (UF 57323, 187.6 mm SL) after re-
moval of the adductor muscles. Anterior is to the right.
C. Medial view of the right pectoral fin (17 rays) ofM
notius (UF 57323, 187.6 mm SL) after removal of the
adductor muscles. Anterior is to the left. Abbreviations:
r ray number; as in Figures 14-15.

Levator pectoralis (LPect, Figs. 2, 6, 7). The
most obvious fibers of this muscle originate on the
pterotic and intercalar and insert on the cleithrum and
posttemporal. Perfunctory attention was paid to this
muscle so additional attachment sites are not described.
Baudelot's ligament. Although possessing no
muscle fibers, this ligament passes from the exoccipital
to a vertical ridge on the medial side of the supracleithrum.

The pectoral girdle consists of the cleithrum,
coracoid, scapula, and four radials with which the rays
articulate. An interosseus septum occurs between the
coracoid and cleithrum. The number of fin rays varies
from 14 to 17 in Micropterus, and spines are absent in
all species. The first ray is the most robust and referred
to as the marginal or leading ray. The interradialis pec-
toralis is absent in all specimens dissected.
Abductor superficialis (AbdS, Fig. 14). This
muscle originates on the posterior side of the lateral
flange of the cleithrum. The individual tendons form a
continuous aponeurotic sheet and insert on the anterior
surfaces of the fin ray bases of all but the marginal or
leading ray.
Abductor profundus (AbdP, Figs. 14, 16). This
muscle is medial to the abductor superficialis and origi-
nates primarily on the lateral surface of the coracoid but
also includes the cleithrum near its ventral tip and the
interosseus septum between these two bones. The lat-
eral surface of the muscle often has a vertical ridge that
coincides with the ventral border of the abductor
superficialis. The development of this ridge is variable
across specimens. The insertion site is the ventral sur-
face of the posteriorly directed flange at the base of the
fin ray. Insertion is tendinous on all rays. The tendon
serving the leading ray arises from fibers only partially
separated from the main abductor mass. The size of
the ray and the tendon serving it decrease at the trailing
end of the fin.
Arrector ventralis (ArrV, Fig. 14). The arrector
ventralis lies anteriorto the abductor profundus and medial
to the abductor superficialis. It originates primarily on
the cleithrum but also includes the anterodorsal corner
of the coracoid and the interosseus septum. Insertion is
on the anteromedial surface of the leading ray via a well-
developed tendon.
Adductor superficialis (AddS 1-3 and AddM,
Fig. 15). Three bundles comprise the adductor
superficialis. The distinct middle bundle is given the name
of adductor superficialis medialis. Bundle one ( 1) is
the most medial section and originates on the dorsal arm
of the cleithrum. It is vertically orientated and inserts on

the more ventral fin rays. The adductor superficialis
medialis (2 AddM) is oblique to 1 and originates on
the cleithrum along the bend where the dorsal and ven-
tral arms converge. Section 2 serves the middle fin rays.
The third section originates on the cleithrum, dorsal cor-
ner of the coracoid, and usually the ventral border of the
scapula and the interosseus septum. Section 3 is twisted
such that tendons from the ventral border of the bundle
serve the dorsalmost fin rays. Tendons insert on the
anterodistal surfaces of the base of all but the leading
fin rays. Tendon length is greatest near ray 8.
Adductor profundus (AddP, Fig. 15). The pro-
fundus muscle is lateral and ventral to the adductor
superficialis. Origin includes the cleithrum, coracoid,
and interosseus septum. Insertion is tendinous on the
ventral surface of a posteriorly directed flange of the fin
ray. It is noteworthy that tendons serving the ventralmost
three rays are greatly reduced in size, and tendons serv-
ing the last two fin rays are closely bound to the ante-
penultimate tendon. Their small size and hidden appear-
ance in combination with neighboring connective tissue
create uncertainty in determining the number of
ventralmost rays served. In the majority of specimens,
all rays except the leading ray are served. Thorsen and
Westneat (2005) report variable insertion patterns, such
as those noted above, in labroids and five additional
percomorph families.
Arrector dorsalis (ArrD, Fig. 15). It originates
on the cleithrum, coracoid, and interosseus space be-
tween cleithrum and coracoid and inserts on the leading
ray. This muscle is graded with the adductor profundus.
Adductor radialis (AddRad, Figs. 15-16. Table
1). This muscle is small and lateral to the adductor pro-
fundus. It originates on the medial sides of radials 2-4.
Anteriorly fibers may also originate on a fine ridge of
the scapula. Insertion is tendinous on the ventralmost
fin rays, the number of which is variable both within
species and individuals (Table 1). In many instances
when the specimen is asymmetrical with respect to the
number of fin rays, the fin with the additional ray usually
has an additional tendon of the adductor radialis although
this pattern is not constant. Given the small size of the
tendons, it is possible that some inconsistencies may be
the result of observation error, although Thorsen and
Westneat (2005) also find interspecific variation of the
adductor radialis among labroids and five additional fami-
lies of coral reef fishes.
Sometimes muscle fibers of the adductor radialis
are found that originate separately on the ventromedial
face of radial 4 [M. coosae, OSUM 105299 (Right side);
M. notius, UF 57323 (R), UF 58761 (L); M. p.


punctulatus USNM 251991 (88.0 mm SL) (R); P
nigromaculatus, ROM 82440 (L, R)] or the coracoid at
its deepest indentation [M. coosae, OSUM 105299 (L),
ROM 82449 (R); M notius, UF 57323 (L); M p.
punctulatus, OSUM 102597 (L); M s. salmoides, ROM
1782CS; M treculii, UMMZ 136849 (L); L. gibbosus,
ROM 82439 (L, R)]. A single specimen may have mul-
tiple conditions.
These fibers comprise a small slip of the adductor
radialis that is lateral to the adductor profundus and clearly
separable from the more lateral abductor profundus which
is exposed in medial view between the coracoid and
fourth radial. This slip is separable from the adductor
radialis at its origin but then grades to varying degrees
with the main adductor mass. A tendon of the slip in-
serts on the last fin ray and is generally either posteri-
orly (if from radial 4) or laterally (if from the coracoid)
displaced relative to tendons from the adductor radialis
although it passes into the main mass prior to insertion in
L. gibbosus (ROM 82439).
Coracoradialis. Fibers originate from the cora-
coid near its deepest indentation and attach tendinously
to a process on the ventromedial face of radial 4 in M
treculii (OSUM 105227, ROM 1784CS). This process
occurs distally at approximately one-third the length of
radial 4 and is not observed in other dissected
centrarchids. The muscle is lateral to the adductor
profundus and medial to a translucent connective sheet
between radial 4 and the coracoid. These two speci-
mens of M. treculii are the largest black bass (> 250
mm SL) dissected and originate from hatchery ponds
(G. Garrett, pers. comm.). Fibers in this same orienta-
tion are present inM d. dolomieu [OSUM 102599 (L),
173.2 mm SL; ROM 82437 (R), 133.2 mm SL] but at-
tach proximally on the ventromedial surface of the fourth
radial in the absence of a process.

The pelvic fin contains one spine and five rays.
The rays are numbered from 1-5 with ray 1 adjacent to
the spine and ray 5 being the most medial. Only M s.
salmoides (ROM 1780CS) deviated from this pattern
with a pelvic fin of 14 (bilaterally).
Abductor superficialis pelvicus (AbdSP, Fig.
17). The abductor superficialis pelvicus originates on
the abductor profundus pelvicus, posterior end of the
basipterygium, and a mid-ventral septum where it joins
its antimere. It grades to varying degrees with the ab-
ductor profundus pelvicus, but the two muscles are most
easily separable posteriorly. The muscle extends -50-
60% of the pelvic length and inserts via an undifferenti-

Table 1. Variation in the insertion sites of three striated muscles: adductor radialis (pectoral fin), hypochordal longitudinalis and flexor ventralis externus (caudal fin); number
of caecae; and nasal rosette inMicropterus and centrarchid species. Standard length (mm) follows the catalogue number for specimens from the same lot. "L" and "R" refer to
the left and right sides of the specimen respectively. "N/A" indicates damage to the musculature or clearing and staining prior to dissection. Adductor radialis: A dash separates
the number of pectoral fin rays from the number of fin rays served. An asterisk following the number of pectoral fin rays indicates that the last fin ray is a rudiment. Hypochordal
longitudinalis, flexor ventralis externus: "D" or "V" refers to caudal fin rays dorsal or ventral to the lateral midline respectively; fin rays are numbered sequentially in either
direction from the midline. Rosette: Rosette notation describes the number of folds (movable flaps of epithelium) and ridges (immobile flaps) dorsal and ventral of a longitudinal
axis. At the posterior end of the longitudinal axis, a single fold is always present and is denoted "/1/". The number of folds is separated from the number of ridges by a colon.
Elements dorsal of the longitudinal axis are left of "/1/" while elements ventral of the axis are right of "/1/". For example, "4:2/1/4:1" indicates 12 rosette elements. Four folds and
two ridges are present dorsal to the longitudinal axis, followed by a single fold at the posterior end of the axis, and four folds and one ridge ventral to the axis. Ridges always
occurred anterior to folds.

Species and Adductor Hypochordal Flexor Ventralis No. of Rosette No. of Rosette
Catalogue Number Radialis Longitudinalis Externus Caecae Formula Elements

A. cataractae
ROM 82445 16-4 16-4 D 5-9 D 4-9 V 1-2 V 1-2 10 5:1/1/5:1 4:2/1/4:1 13 12
UMMZ 168752 16-4 16-3 D 5-9 D 5-9 V 1-2 V 1-2 12 3:0/1/2:0 N/A 6 N/A

A!. coosae
OSUM 105229 16 -4 16 -4 D 4-9 D 5-9 V 1-2 V 1-2 10 3:0/1/3:0 2:1/1/2:1 7 7
ROM 82449 15-3 15-3 D 5-9 D 5-9 V 1-2 V 1-2 10 3:0/1/3:0 3:0/1/3:0 7 7
ROM 82450 15-3 15-3 D 6-9 D 4-9 V 1-2 V 1-2 9 3:0/1/2:1 3:0/1/3:0 7 7
UF 86268 15-4 15-4 D 3-8 D 3-8 absent absent 10 4:0/1/3:0 4:0/1/3:0 8 8
UF 86313 16-4 16-3 D 5-9 D 5-9 V 1-2 V 1-2 8 4:0/1/3:1 4:0/1/3:1 9 9
UF 89989 N/A- 5 N/A-4 D 5-9 N/A V 1 V 1-2 13 N/A N/A N/A N/A
USNM 168075 14* 3 16-4 D 5-9 D 3-9 V 1-3 V 1-2 11 3:1/1/3:1 3:1/1/3:1 9 9

AM. d. dolomieu
ROM 1783CS 16-4 16 -4 D 6-9 D 5-9 V 1-2 V 1-2 16 N/A N/A N/A N/A
ROM 82436 16 -4 16 -3 D 4-9 D 4-9 V 1-2 V 1-2 14 6:0/1/5:0 6:0/1/5:0 12 12
ROM 82437 16-4 17 -5 D 6-9 D 5-9 V 1-2 V 1-2 12 4:0/1/4:0 3:1/1/3:1 9 9
OSUM 102599 16-4 16-4 D 4-9 D 4-9 V 1-2 V 1-2 12 5:0/1/5:0 4:1/1/2:0 11 8
OSUM 102600 16-4 16-4 D 5-9 D 5-9 V 1-2 V 1-2 14 4:0/1/4:1 4:1/1/3:2 10 11

AM. d. velox
USNM 116802 17-4 17-4 D 3-9 D 4-9 V1-2 V1-2 10 3:0/1/2:1 3:1/1/2:1 7 8
USNM 128680 16-4 16 -4 D 5-9 D 5-9 V 1-2 V 1-2 12 3:1/1/3:0 3:0/1/3:0 8 7

A. notius
UF 57323 17-5 17-6 D 5-9 D 5-9 V 1-2 V 1-2 11 2:0/1/2:0 2:0/1/1:1 5 5
UF 58761 (131.8) 17-4 17-4 D 5-9 D 5-9 V 1-2 V 1-2 12 4:0/1/4:0 5:0/1/4:1 9 11
UF 58761 (145.2) 16-5 16 5 D 5-9 D 5-9 V 1-2 V 1-2 11 4:1/1/4:0 4:1/1/4:1 10 11
TU 9775 (107.4) 16-5 16 5 D 5-9 D 6-9 V 1-2 V 1-2 12 1:0/1/1:0 1:0/1/1:0 3 3
TU 9775 (152.3) 16-5 16-4 D 6-9 D 5-9 V 1-2 V 1-2 12 1:0/1/1:0 N/A 3 N/A

Table 1. Cont.

Species and Adductor Hypochordal Flexor Ventralis No. of Rosette No. of Rosette
Catalogue Number Radialis Longitudinalis Extemus Caecae Formula Elements

M. p. punctulatus
OSUM 102597
OSUM 102598
USNM 251991 (95.4)
USNM 251991 (88.0)

M. p. henshalli
UAIC 10587.15
UAIC 12652.19

M. s. floridanus
UMMZ 158634
UMMZ 163350

M. s. salmoides
ROM 1780CS
ROM 1781CS
ROM 1782CS
ROM 82435
ROM 82446 (153.2)
ROM 82446 (173.0)
ROM 82446 (214.4)
ROM 82446 (219.4)

M. treculii
OSUM 105227
ROM 1784CS
UMMZ 136849
UMMZ 220247

15 -3
14 2

15 -3
14- 3

D 5-9
D 3-9
D 5-9
D 5-9

16-4 16-4 D5-9
16-5 16-4 D6-9

15-4 15-4 D6-9
15-4 15-4 D6-9

14 N/A
14* 3

16 -4

15 N/A

15 -4

D 6-9
D 6-9
D 6-9
D 6-9
D 6-9
D 6-9
D 6-9
D 6-9

D 4-9
D 4-9
D 3-9
D 5-9

A. ariommus
ROM 82444 14-4 15-4 D 4-9

C. macropterus
UMMZ 164961

L. cyanellus
ROM 82438

L. gibbosus
ROM 82439

P. nigromaculatus
ROM R2440

13 -3 13-3 D 5-9

13 -3 13-3 D 5-9

13 -2 13-3 D 5-9

14- 3 14-4 T 7-9

D 5-9
D 3-9
D 5-9
D 5-9

V 1-2
V 1-2
V 1-2
V 1-2

see text
V 1-2
V 1-2

D5-9 V1-2 V1-2
D5-9 V1-2 V

D5-8 V1-2 V1-2
D5-9 V 1-2 V 1-2

D 6-9
D 5-9
D 6-9
D 6-9
D 6-9
D 6-9

D 5-9
D 4-9
D 3-9
D 3-9


D 5-9

V 1-2
V 1-2
V 1-2
V 1-2

V 1-3
V 1-2



6:0/1/5:0 5:0/1/5:0 12
5:1/1/4:1 4:1/1/4:1 12

37 2:1/1/2:1 2:0/1/2:1
40 3:1/1/4:0 4:0/1/4:0

V 1-2
V 1-2

V 1-2
V 1-3
V 1-2

V 1-2 V 1-3

V V1-2

D 5-9 V 1-2 V 1-2

D5-9 V1-3 V1-3





7 2:1/1/2:1 3:0/1/2:1

8 4:1/1/4:1 6:0/1/5:0 11 12

4 3:0/1/2:1 2:2/1/2:1

7 2:2/1/3:1 4:0/1/2:1

D 6-9 V 1 V 1 41/1/4-0 41/1/4-1

10 11

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

ated tendinous sheet to the spine and all rays on the
anterior surface of their medially directed, basal flanges.
Hypaxial fibers attach to this muscle via myocommata
and complete separation of the two muscles is very dif-
Abductor profundus pelvicus (AbdPP, Fig. 17).
This long muscle originates on the basipterygium and
mid-ventral septum and extends -80% of the pelvic
length. The insertion is tendinous on the dorsal surfaces
of the five rays but not the spine.
Arrector ventralis pelvicus (ArrVP, Fig. 17). This
muscle originates on the ventral side of the pelvis, lat-
eral to the abductor profundus pelvicus, although some
fibers may extend medially onto it. The arrector ventral
pelvicus extends to the anterior end of the pelvis but not
beyond it. Insertion is tendinous on the proximal, ventral
surface of the spine.
Adductor superficialis pelvicus (AddSP, Fig.
17). This muscle originates on the dorsal side of the
adductor profundus pelvicus and basipterygium near the
posterior pelvic process. Antimeres converge at the
midline but are not in contact; the muscle extends -75%
of the pelvic length. Tendons insert on the anterior faces
of the medially directed flanges of the spine and first
four rays. The fifth ray does not possess a medially
directed flange and consequently is not served by the
adductor superficialis pelvicus.
Adductor profundus pelvicus (AddPP, Fig. 17).
This long muscle originates on the basipterygium and
extends to the anterior tip of the pelvis but not beyond it.
The tendons form a continuous sheet that attaches to
the anterior surfaces of the five rays. This attachment
site is ventral to that of the adductor superficialis pelvicus.
Arrector dorsalis pelvicus (ArrDP, Fig. 17). The
arrector dorsalis pelvicus originates on the lateral side
ofthe basipterygium. Posteriorly the bundle sits in a well-
defined bony groove of the basipterygium. Fibers may
extend ventrally onto the arrector ventralis pelvicus. It
extends anteriorly -75% of the pelvic length. A large
tendon inserts on the proximal, lateral surface of the
Extensor proprius (ExtP, Fig. 17). This small,
but well-developed muscle originates on the adductor
superficialis and profundus pelvicus with fascia extend-
ing laterally to the basipterygium. Insertion is on the
dorsal, distal surface of ray 5, where a small tuberosity
is present. Micropterus coosae (OSUM 105229) and
M. treculii (ROM 1784CS) each possess one bundle
that attaches to rays 4 and 5, while its antimere attaches
to ray 5. The extensor proprius inserts on ray 4 bilater-
ally inM s. salmoides (ROM 1780CS), which has only
four fin rays.











Figure 17. Pelvic fin musculature of M s salmoides
(ROM 82446, 153.2 mm SL). Anterior is to the left.
Scale bar = 5 mm. A. Dorsal view of the pelvis. The
left antimeres of the extensor proprius and adductor
superficialis pelvicus have been removed. B. Ventral
view ofthe pelvis. The left abductor superficialis pelvicus
antimere has been removed. C. Left, lateral view of the
pelvis including the ventral tip of the left cleithrum. Ab-
breviations: AbdPP abductor profundus pelvicus;
AbdSP abductor superficialis pelvicus; AddPP ad-
ductor profundus pelvicus; AddSP adductor
superficialis pelvicus; ArrDP- arrector dorsalis pelvicus;
ArrVP arrector ventralis pelvicus; ExtP extensor
proprius; Hyp hypaxialis; ICA infracarinalis ante-
rior; ICM infracarinalis medialis; spine pelvic spine;
as in Figures 14 and 16.


r--- -:

S ,/







/ /



Figure 18. Left, lateral views of the caudal fin muscula-
ture. Anterior is to the left. Scale bar = 5 mm. A. M.
coosae (UF 86268, 131.8 mm SL) after removal of the
epaxialis and hypaxialis. Note that the flexor ventralis
extemus is missing and the dorsalmost insertion of the
hypochordal longitudinalis is to the eighth ray dorsal of
the lateral midline. B.M p. punctulatus (OSUM 102598,
144.7 mm SL) after removal of the epaxialis and
hypaxialis. The solid black line is a nerve. Abbrevia-
tions: D dorsalmost caudal ray served by the hypo-
chordal longitudinalis; FD flexor dorsalis; FDS flexor
dorsalis superior; FV flexor ventralis; FVE flexor
ventralis extemus; FVI flexor ventralis internmus; HL -
hypochordal longitudinalis; ICP infracarinalis poste-
rior; IntRad interradialis; SCP supracarinalis poste-
rior; V ventral caudal rays served by flexor ventralis


There are 17 principal caudal rays in black bass;
nine dorsal and eight ventral to the midline. The outer-
most principal caudal rays are segmented and un-
branched (Schultze & Arratia 1989). These rays are
numbered sequentially beginning at the midline, with those
dorsal and ventral to the midline denoted "D" and "V"
respectively. Thus, "V6" is the sixth principal caudal
ray ventral to the midline. Along the dorsal and ventral
margins of the caudal fin are a variable number of
procurrent rays which may be segmented but are un-
branched (Schultze & Arratia 1989). The caudal fin of
Micropterus species is typically composed of three
epurals, two uroneurals, and five autogenous hypurals.
The ural complex (pUl and caudal centra) is ossified
and fused as a single entity. Vertebrae anterior to the
ural complex are denoted "pU#" starting with pU2 and
sequentially numbered anteriorly. The neural spine of
pU2 is short. Cartilaginous distal radials lie distal to the
neural and hemal spines of pU3-pU4 or pU4-pU5 and
anterior to the procurrent caudal rays. The adductor
dorsalis is absent in all species observed.
Interradialis (IntRad, Fig. 18). The interradialis
originates and inserts on caudal rays and usually over-
laps several fin rays. These bundles span from V8 to
D8 or D9. In addition, separate bundles occur between
D9-10 and D8-10. At the middle of the fin, fibers origi-
nate from a single attachment site on V proximally and
insert broadly along the ventral side of Dl. Medially
this arrangement is reversed with fibers originating on
Dl and fanning onto V 1.
Hypochordal longitudinalis (HL, Fig. 18. Table
1). This muscle is asymmetrical and originates on the
ural complex, hypurapophysis, head of the hypural,
hypural plates 1-3, and in some specimens on the cen-
trum of pU2. Insertion is tendinous on a variable num-
ber of fin rays (Table 1). With two exceptions (M.
coosae, UF 86268; M s.floridanus UMMZ 158634),
the dorsalmost fin element is D9. The tendon serving
D9 is the largest. The site of attachment is the
anteroventral comer of the ventralmost fin ray, but the
site moves distally on more dorsal fin rays. Often the
tendon serving the ventralmost ray 'hides' against the
posteromedial surface of the preceding tendon thus lead-
ing to erroneous observations. Removal of singular and
minor variants reveals D5-9 as the generalized condi-
tion with M s. floridanus and M s. salmoides charac-
terized by D6-9.
Flexor dorsalis (FD, Fig. 18). The flexor dorsa-
lis originates on the centra and neural spines of pU2-5,
ural complex, epurals, uroneurals, hypural plates 4-5 and
variably on hypural plate 3. Insertion is tendinous on the

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

anterior ends of D 1-8 with the insertion moving to the
lateral surface at D8.
Tendons serving D7 and D8 become 'stringy',
meaning that they appear to be comprised of multiple
strands and therefore multiple insertion sites. On many
specimens, two tendons appear to insert on D8. One
tendon inserts medially in an orientation consistent with
tendons of the flexor dorsalis, while a more distal and
lateral insertional site is consistent with the flexor dorsa-
lis superior. Under this interpretation, both the flexor
dorsalis and flexor dorsalis superior insert on D8 in a
majority of specimens. At times, a similar orientation is
observed on D7.
Flexor dorsalis superior (FDS, Fig. 18). The
flexor dorsalis superior originates muscularly on the
epurals, distal tip of neural spine pU3, and tendinously
on distal radial at the tips of neural spines pU4 or pU5.
This distal radial is serves as an attachment site for the
supracarinalis posterior, but the two muscles are not
continuous as the flexor dorsalis superior is removable
largely without affecting the supracarinalis posterior. The
flexor dorsalis and flexor dorsalis superior are graded.
The most common insertion is on the dorsal, distal sur-
faces of D8-D12 but may vary to either D8-D11 or D8-
Flexor ventralis (FV, Fig. 18). The flexor ven-

i t' /

tralis originates on the parhypural, hypurapophysis, ural
complex, hypural plate 1, centra pU2-5, and hemal spines
pU2-3. The centrum of pU5 and hemal spine of pU4
may variably be included. Insertion is on the anterior
faces of V1-8 with the site moving anterodorsally from
VI to V8.
Flexor ventralis inferior (FVI, Fig. 18). This
muscle is chevron shaped and separable from the flexor
ventralis. Origin of the dorsal arm includes hemal spines
pU2-3 while the ventral arm originates on the distal tip
of hemal spine pU4 and distal radials between hemal
spines pU3-pU4 or pU4-pU5. The infracarinalis poste-
rior also attaches to this distal radial where some fibers
may grade with the flexor ventralis inferior. The most
common insertion is on the ventrodistal surfaces of V9-
11 but may vary to either V9-V10 or V9-V12.
Flexor ventralis externus (FVE, Fig. 18. Table
1). This small slip of a muscle originates on a combina-
tion ofcentrapU3-5 and hemal spines of pU2-3. Poste-
riorly, fibers disappear into an aponeurosis which yields
long and slender tendons that insert on a variable num-
ber of caudal fin rays (Table 1). Often a single tendon
will extend to a point between two adjacent fin rays thus
appearing to insert on both rays. This pattern was inter-
preted as a single tendon which should serve a single
ray, the dorsalmost of the two rays. The flexor ventralis



Figure 19. Branching patterns of the pyloric caecae.
Scale bar = 5 mm. A. and B. Two observed patterns of
branching in M s. floridanus (UMMZ 158634, 128.8
mm SL). C. M cataractae (UMMZ 168752, 102.8 mm
SL) has 12 single caecae surrounding the stomach. The
intestine has not been included.

Figure 20. Left, lateral view of the nasal rosette. Dotted
line indicates the extent of the nasal capsule. Scale bar
= 1 mm. A. M coosae (UF 86268, 131.8 mm SL).
Pattern notation is 4:0/1/3:0 as described in Table 1. B.
M notius (UF 58761, 131.8 mm SL). Pattern notation
is 4:0/1/4:0.


externus grades with the hypaxialis inM.p.punctulatus
(OSUM 102599) and the flexor ventralis in M. s.
salmoides (ROM 82446, 219.4 mm). In both instances,
their respective insertions remain distinct. Micropterus
coosae (UF 86268) is unique in lacking a flexor ventra-
lis extemus.

Pyloric Caecae (Fig. 19). Pyloric caecae are blind
sacs that circle the intestine immediately below the stom-
ach. They are assumed to increase retention time of
food and therefore serve to facilitate protein digestion
and fat or carbohydrate absorption (Barrington 1957).
The structure and numbers of caecae are variable among
species and absent in other species (e.g. Cyprinidae).
The number of caecae and the presence of branched
caecae are not independent characters although they
are described separately.
Micropterus s. floridanus and M. s. salmoides
have predominantly branched caecae that occur vari-
ably along the length of the caecum. Frequently a cae-
cum has multiple branches resulting in a single base hav-
ing three, four, and in one instance, seven tips (M. s.
salmoides, ROM 82446, 153.2 mm). The remaining
species of Micropterus and other centrarchids have

oo. ..

0 *,'*


predominantly unbranched caecae. In the majority of
these latter exceptions, adjacent branches share part of
their walls and thus are caecae not completely sepa-
rated from each other (M. coosae UF 89989, USNM
168075; M d. dolomieu OSUM 102600, ROM 82436;
M p. punctulatus OSUM 102597).
M s. floridanus and M s. salmoides have the
most caecae averaging 38.5 and 27.9 respectively. The
remaining species ofMicropterus average 9.0 (treculii),
10.0 10.8 (coosae, henshalli, punctulatus), 11.0 -
11.6 (cataractae, notius, velox), and 13.6 (dolomieu)
caecae. The single specimen of each outgroup species
has eight (Pomoxis, Centrarchus), seven (Ambloplites,
Lepomis gibbosus), or four (Lepomis cyanellus)
caecae (Table 1). If branches are ignored, M. s.
floridanus and M s. salmoides average 14.0 and 10.0
bases respectively and fall within the range of other
Micropterus species.
Nasal rosette (Figs. 20, 21. Table 1). The nasal
rosette consists of a number of folds in the nasal epithe-
lium arranged above and below the longitudinal axis of
the nasal cavity, with a single fold at the posterior end of
this axis. This arrangement results in an odd number of
folds with an equal number of folds above and below
the longitudinal axis. 'Folds' and 'ridges' were differen-
tiated based on their flexibility. A fold is defined as flex-

70 120 170 220 270

standard length (mm)

70 120 170 220 270

standard length (mm)

Figure 21. A. Scatterplot of the average number of rosette structures (folds and ridges) per specimen against stan-
dard length forMicropterus species (filled circles, solid line) and outgroups (open circles, dashed line). B. Scatterplot
of the average number of rosette structures per specimen against standard length for each Micropterus and outgroup
species. Subspecies have not been differentiated. Lines of best fit were forced through the origin. Abbreviations: C -
M cataractae; D M dolomieu; N M. notius; 0 M coosae; P M punctulatus; S M salmoides; T M

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

ible piece of tissue that 'flops' when pushed with a probe,
whereas a ridge is immobile resembling a speed bump.
Folds are always posterior to ridges. The fold is simple,
not crenulated, such that a cross-section resembled a
keyhole. In the notation below, the number of folds pre-
cedes the number of ridges and is separated by a colon.
A backlash on either side of "1" represents the single
fold along the horizontal axis. The number of folds and
ridges ventral of the axis follows in a format consistent
with the number of dorsal structures (Table 1). For ex-
ample, the rosette pattern "4:1/1/3:2" has 11 structures
in total. Dorsal to the axis are four folds and a single
ridge, followed by a single fold parallel to the longitudi-
nal axis. Three folds and two ridges are ventral to the
Rosette size and the number of elements within
the rosette increase with standard length. Variation in
standard length explained 47% and 20% of the variation
in the number of rosette elements for outgroup and
ingroup species respectively (Fig. 21A). Analysis by
ingroup species resulted in five clusters of species (Fig.
21B). The positive relationship between standard length
and the number of rosette elements is supported by ob-
servations that smaller (ridges) and 'missing' elements
(denoted by appropriate spaces) are found at the ante-
rior end of the rosette. Posterior elements (folds) are
always larger and thus presumably older than more an-
terior elements (ridges). In instances of asymmetry
above and below the longitudinal axis, elements on the
dorsal side of the longitudinal axis are either more nu-
merous or more developed than elements below the lon-
gitudinal axis.

Myological descriptions of Micropterus are
consistent with the conditions of other teleosts
(Winterbottom 1974a) and specific observations of the
dorsal branchial arch muscles in M dolomieu (Springer
& Johnson 2004). A "universal division" (Wu & Shen
2004) of the adductor mandibulae originates from the
hyomandibula and palatal arch and passes lateral to ra-
mus mandibularis V (RMV) to insert on the Meckelian
fossa and a shared myocommatum with Ai Wu &
Shen (2004) identify this section as A2a and synony-
mize it with A2a ofWinterbottom (1974a) andA2-A3 of
Gosline (1989). The A3 division described herein is the
universal division, and the graded A -A2 section is the
Al-A2a bundle sensu Wu and Shen (2004). The pres-
ence of an A 1-A2a bundle with autonomous divisions of
A2a and AM in the absence of A3 appears to be a gen-
eral characteristic of Perciformes (Wu & Shen 2004).

Divisions of the adductor mandibulae have come
under recent scrutiny in an effort to determine the reli-
ability of the course of RMV. One school notes that the
path of RMV through divisions of the adductor
mandibulae is variable and phylogenetically uninforma-
tive (Edgeworth 1935; Winterbottom 1974a; Gill & Mooi
1993). An opposing view suggests that the path of RMV
may be phylogenetically informative (Gosline 1989; Diogo
& Chardon 2000; Nakae & Sasaki 2004; Wu & Shen
2004), with the primary obstacle to robust interpreta-
tions being comparisons among non-homologous divi-
sions of the adductor mandibulae. This latter opinion
implies that if the problem of non-homology among divi-
sions of the adductor mandibulae is resolved, the path of
the RMV would likely contain a recoverable phyloge-
netic signal (Gosline 1989). Evolutionary models ex-
plaining the origin and pattern of division of the adductor
mandibulae were then developed (Gosline 1986, 1989;
Diogo & Chardon 2000; Wu & Shen 2004). However,
such explanations are based on the a priori premise
that the course of the RMV is a valid taxonomic char-
acter. While it is highly probable that nerves, and their
paths, retain a phylogenetic signal, we seek to avoid the
circularity of employing the path of RMV to identify
divisions of the adductor mandibulae. An ontogenetic
analysis of the adductor mandibulae may resolve this
dilemma and inform the larger issue of using nerves to
identify muscles.

Black bass display all four classes of myological
variation: minor, incongruous, singular, and mimicking.
Minor variants are slight differences in the size, shape,
or position of the muscle arising from a variety of fac-
tors including biological (specimen health, age, sex, etc.)
and non-biological (storage, preservation) effects. Ex-
amples include variable lengths of the pelvic adductors
and abductors and the variable origin of the adductor
hyomandibulae on the prootic, the pterotic, or both bones
due to the fimbricate suture between them. By describ-
ing the generalized condition of a species, minor vari-
ants are necessarily excluded.
Incongruous variants result in nonfunctional
muscles and include cases of absent muscles normally
present or shifted insertions, which have negated the
original function of the muscle. The sole example of a
muscle absent in a specimen was the flexor ventralis
externus (caudal fin, M coosae, UF 86268).
Singular variants are atypical and unique to a given
specimen. Examples from centrarchids include three
bundles of rectus ventralis IV (ventral branchial arches)
either all serving the U-shaped ligament (M. treculii,

ROM 1784CS) or the U-shaped ligament and cupula
(Centrarchus macropterus, UMMZ 164961) and the
shared origin of the flexor ventralis extermus (caudal fin)
with either the flexor ventralis (M s. salmoides, ROM
82446, 219.4 mm SL) or the hypaxialis (M. p.
punctulatus, OSUM 102597). Presumably these
muscles retain their original functions despite an altered
insertion or origin.
Polymorphic states of the adductor radialis (pec-
toral fin), hypochordal longitudinalis (caudal fin), and
flexor ventralis extermus (caudal fin) are a result of mim-
icking variants which atypically resemble the usual con-
dition of another species. Identifying the cause of this
variation is problematic but it could result in part from
fluctuating developmental conditions or phenotypic plas-
ticity induced by locomotory differences between indi-
viduals. While some variation may be the result of dis-
section errors, safeguards against observer bias were
employed. A random dissection order and independent
dissections of the bilateral elements in the same indi-
vidual suggest that intra-individual, intraspecific, and in-
terspecific variation is considerable in black bass.
A fifth, and rare, trait-category characterized by a
high frequency of diverse morphologies is "explosive"
variation (Raikow et al. 1990). The breadth of variation
in the adductor radialis (pectoral fin) might be consid-
ered explosive and likely results from a combination of
mimicking and singular variants. In addition, an unex-
plained compensatory mechanism exists whereby the
number of pectoral rays served by the muscle co-varies
with the number of fin rays present, even within the
same specimen. If meristic variation such as the num-
ber of fin rays can influence the number of insertion
sites, a similar pattern between muscles and other serial
bony elements might be expected. The extensor pro-
prius (pelvic fin) inserts on the medialmost ray, which is
usually the fifth ray in black bass; however, it can insert
on the fourth ray in the absence of the fifth ray (M. s.
salmoides, ROM 1780CS).
Finally, specimens possessing one incongruous or
singular variant often possessed a second or third vari-
ant. Why variants accumulate in some individuals is not
clear, but a variety of intrinsic (genetics, life history, body
size Billerbeck et al. 1997, McDowall 2003) and ex-
trinsic (fluctuating environmental conditions e.g.,
Gabriel 1944, Hubbs 1959) factors experienced during
development are long known to affect the meristics of
serial bony elements. For instance, an increase in ver-
tebrae but a decrease in anal fin rays is attributed to
colder water temperatures experienced by larval M p.
punctulatus at two of nine locations in the Ohio River
(Bryan 1969). Observations from the present study sug-


gest that co-variation in the number of fin rays and the
number of insertion sites occurs in the adductor radialis
(pectoral fin) and the extensor proprius (pelvic fin). For
example, bilateral differences in the number of pectoral
fin rays occurred in seven specimens, and in six of those
the number of rays served by the adductor radialis in-
creased as the number of fin rays increased. If envi-
ronmental conditions affect meristic variation and myo-
logical variation is tied to the meristic counts of fins and
vertebrae, for instance, then fluctuating environments
may also contribute to myological variation. This line of
reasoning is in contrast to Raikow et al. (1990, p. 367),
who asserted "that neither sexual difference nor indi-
vidual developmental instability contributes ',,,, ', ,U ,,l'
to intraspecific myological variation" in passerine birds
(emphasis added). How much variation constitutes "sub-
stantial" variation is not clear.

Micropterus species share a remarkably uniform
external morphology characterized by a fusiform body,
large mouth, and posterior extension of the median fins.
Myologically they display minor variation of the cheek,
jaws, branchial and hyoid complexes and slightly more
variation in the pectoral and caudal fin complexes. Ad-
ditionally, Jayne and Lauder (1994) found M salmoides
had the least variation in the linear dimensions of the
myoseptal system relative to one species each of
Lepomis, Pomoxis, and Ambloplites. Ecologically, black
bass are ram feeders of elusive prey such as fishes and
crayfishes. Biogeographically, black bass and their sis-
ter group Lepomis (Near et al. 2005) occupy most of
the same drainages, but Lepomis is more diverse in the
Mississippi basin whereas Micropterus is more diverse
along the Gulf Coast and southeastern Atlantic drain-
ages where M cataractae, M coosae, M notius, M
p. henshalli, and M s. floridanus are restricted (Lee
et al. 1980). Geographical outliers include M. treculii of
the Guadalupe River basin in Texas and M. d. velox of
the Neosho River and tributaries of the Arkansas River
on the western slope of the Ozark Plateau (Koppelman
& Garrett 2002). The remaining species of black bass
are distributed from the southern USA, northward into
the Ohio River basin (M. p. punctulatus) and Great
Lakes including Ontario and Quebec (M d. dolomieu,
M s. salmoides) (Scott & Crossman 1973; Lee et al.
1980; Trautman 1981).
Studies of ecological morphology have concluded
that a strong relationship exists between feeding anatomy
and diet among fish guilds (e.g., Wainwright & Lauder
1992; Wainwright & Richard 1995), although the ab-
sence of a direct one-to-one correlation between mor-

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

phology and function has been noted (Norton 1995;
Wainwright et al. 2005; Collar &Wainwright 2006; Dean
et al. 2007). A fuller appreciation of the evolution of the
family Centrarchidae requires a consideration of the sta-
sis exhibited by one major lineage,Micropterus, in com-
parison to the ecological and morphological variation
exhibited by its sister lineage, Lepomis, which likely di-
verged from each other about 25 mya (Near et al. 2005).
The conservatism in Micropterus stands in con-
trast to the morphological diversity of the 12 species of
Lepomis, which are primarily suction feeders on a range
of sedentary to elusive and soft-bodied to hard-bodied
prey (Collar et al. 2005). Comparison of the relation-
ship between diet and morphological diversity in
Micropterus and Lepomis supports the assertion that
highly diverse diets across Lepomis spp. are correlated
to changes in those elements of the skull, jaws, and sus-
pensorium related to food acquisition (Lauder 1983;
Wainwright & Lauder 1992; Wainwright & Shaw 1999;
Collar et al. 2005). The higher rate of evolution in
Lepomis (Collar et al. 2005) is driven in part by diet or
habitat specialization resulting in differential biomechani-
cal efficiencies and is evidence of natural selection act-
ing in a directional manner (Ehlinger 1990; Cutwa &
Turingan 2000 and references therein; Thorsen &
Westneat 2005; Wintzer & Motta 2005 and references
therein; Higham 2007).
The high degree of myological and overall mor-
phological stasis among Micropterus species indicates
natural selection has been stabilizing, not directional, and
suggests that speciation in this lineage is driven not by
ecological specialization but more probably by vicariant
events, a conclusion also arrived at by Near et al. (2003).
At least in this taxonomic example, speciation events in
a static lineage may retain a clearer signal of vicariant
geological events when compared to a more speciose
lineage whose cladogenesis results from a mixture of
ecological, behavioral, and life history specialization as
well as vicariance.
The majority of speciation events in Micropterus
occur during great topographic and climatic change dur-
ing the Cenozoic of North America (Near et al. 2003,
2005). Warm, tropical temperatures with minimal latitu-
dinal variation in the Eocene gave way to more modem
conditions of cooler temperatures (drop of mean annual
temperature 8.2 + 3.1 C, Zanazzi et al. 2007), and sea-
sonal and latitudinal variation in the Oligocene across
central North America (Prothero et al. 2003). The early
Miocene (23-17 mya) witnessed large-scale changes in
the size of the Antarctic ice sheet (Pekar & DeConto
2006). The cooling phase was marked by Antarctic ice
sheet expansion during the middle Miocene (-14 mya,

Holboum et al. 2005) and subsequent sea level fluctua-
tions as the Antarctic ice sheet waxed and waned. The
timing of late Miocene-early Pliocene sea fluctuations is
consistent with the majority of speciation events in
Micropterus which are dated to this period (Near et al.
2003, 2005). Fluctuating sea levels may have produced
vicariant isolation events at watershed levels. Stabiliz-
ing selection resulting in conservative black bass mor-
phology and ecology is reflective of a stable river habi-
tat during the late Miocene and early Pliocene. Other
morphologically static perciform groups such as
moronids and non-darter percids may also be reliable
identifiers of historical geological events that resulted in
allopatric speciation during this time.
An alternative hypothesis leading to an increased
rate of speciation inMicropterus, and consequently other
lineages of North American freshwater fishes, is sec-
ondary effects of the tremendous uplift of the Colorado
Plateau in Western North America. During the Miocene,
Colorado Plateau uplift began about 20 mya and formed
the Colorado River less than 6 mya (Dorsey et al. 2007).
The large western uplift of the Colorado Plateau may
have resulted in a much lesser but still significant uplift
in eastern North America (i.e., exhumation of the Appa-
lachians during the Miocene-Pliocene), with the effect
of entrenching some established eastern river systems
(eg., the Susquehenna, New River, Green and
Cumberland systems), and isolating other drainages along
the Gulf Coast and Atlantic. An explanation of eastern
North American uplift in the Mio-Pliocene, although
speculative, is consistent with the phylogenies of
Catostomidae, Ictaluridae, and Percidae where mem-
bers of basal lineages (Carpiodes, Ictiobus in
Catostomidae, Harris & Mayden 2001; Ictalurus and
Pylodictis in Ictaluridae, Sullivan et al. 2006; Perca in
Percidae, Wiley 1992) are lower gradient, large river or
more lacustrine than derived lineages which occupy
higher gradient habitats. The current habitats occupied
by Micropterus, moderate-sized rivers of moderate to
higher gradient, suggest it would be subject to the selec-
tive pressure generated by uplift.

Within the context of this study, muscle complexes
in the caudal and pectoral fins exhibit the greatest varia-
tion while complexes of the branchial gill arches, cheeks,
and pelvic fin are static. The high frequency of mimick-
ing variants in the caudal and pectoral fins necessitates
the use of alternative coding methods to incorporate
intraspecifically polymorphic characters into phylogenetic
analyses (e.g., Wiens & Servedio 1997; Wiens 1999,
2001). Overall, the paucity of myological characters

suitable for phylogenetic analysis at low taxonomic lev-
els, including Micropterus, and their relative rarity com-
pared to osteological characters at these same taxonomic
levels is a generally supported tenet (Kesner 1994 and
references therein; Borden 1998; Diogo 2004). How-
ever, across higher taxonomic levels, these five muscle
systems (cheek, branchial gill arches, paired fins, caudal
fin) are evolutionarily stable complexes that provide nu-
merous myological characters suitable for comparative
and systematic analyses of teleosts and perciforms.
Higher taxonomic levels usually circumscribe greater
ecological diversity, which may yield greater anatomical
Rightly or wrongly, static lineages are often con-
sidered to be generalized starting points when examin-
ing ecological, trophic, or morphological diversity within
a larger clade. This perception explains in part why
generalized species (i.e., members of static lineages)
are often selected as outgroups to polarize character
transformation series in phylogenetic analyses. Certainly,
the interest and attention of many investigators are drawn
to diverse and speciose groups where hypotheses of
ecologically-driven divergence mechanisms are possible
to test, but static lineages resulting from stabilizing se-
lection give a different but equally valuable perspective
into the study of evolutionary mechanisms.
Because static lineages are difficult to resolve phy-
logenetically at low taxonomic levels using morphology,
their most efficient application in systematics may be at
unraveling higher-level relationships. Conversely, diverse
lineages may have higher resolution at lower taxonomic
levels but the use of species with specialized morpholo-
gies to serve as outgroups or exemplars of clades in
higher-level systematics may introduce unintended bi-
ases into analyses. Systematists wishing to incorporate
myology, and morphology more generally, into macro-
evolutionary studies at low taxonomic levels might esti-
mate the relative cost in time and effort of muscle dis-
sections by assessing the ecological diversity of the
ingroup. A cost-benefit assessment a priori may yield
more efficient systematic research, although ultimately
it is the distribution of character states that is more rel-
evant than the number of characters (Kesner 1994).

We thank a number of people for the loans and gifts of
material including R. Robins, T. Vigliotti, L. Page, and J.
Albert (FLMNH), R. Winterbottom (ROM), B. Kuhajda
(UAIC), J. Williams, S. Smith, and S. Jewett (USNM),
N. Rios and H. Bart, Jr. (TU), D. Catania (CAS), T.
Cavender and M. Kibbey (OSUM), D. Nelson (UMMZ),
G Steinhart and R. Stein (OSU), B. Shaner, P. Landford,


and J. Biagi (GADNR), G Garrett (TXDP&W), and J.
Williams (USGS-FL). C. Sheil (JCU) kindly made space
and time for use of a camera lucida and critiques of the
illustrations, and P. Doerder (CSU) patiently endured
his ciliate lab smelling of preserved fish. R. Krebs (CSU),
D. Franz (FLMNH), and one anonymous reviewer pro-
vided valuable critiques of the manuscript. In particular,
we thank E. Hilton (FMNH) for a careful review of the
manuscript and his many valuable suggestions. The
Department of Biological, Geological, and Environmen-
tal Sciences (CSU) provided support to WCB.

Avise, J. C., D. 0. Straney, & M. H. Smith. 1977. Bio-
chemical genetics of sunfish IV. Relationships of
centrarchid genera. Copeia, 1977:250-258.
Bailey, R. M. 1938. A systematic revision of the
centrarchid fishes, with a discussion of their distribu-
tion, variations, and probable interrelationships. Ph.
D. dissertation. University of Michigan, Ann Arbor.
256 p.
Bailey, R. M., & C. L. Hubbs. 1949. The black basses
(Micropterus) of Florida, with description of a new
species. Occasional Papers, Museum of Zoology,
University of Michigan, 516:1-40 + 2 plates.
Barrington, E. J. W. 1957. The alimentary canal and
digestion. Pp. 109-161 in M. E. Brown, ed. The Physi-
ology of Fishes. Vol. 1 Metabolism. New York: Aca-
demic Press, 447 p.
Billerbeck, J. M., G Orti, & D. 0. Conover. 1997. Lati-
tudinal variation in vertebral number has a genetic
basis in the Atlantic silverside, Menidia menidia.
Canadian Journal of Fisheries and Aquatic Sciences,
Blair, Jr., C. B., & W. N. Brown. 1961. The osteology
of the red eye bass, Micropterus coosae (Hubbs
and Bailey). Journal of Morphology, 109:19-36.
Bock, W. J., & C. R. Shear. 1972. A staining method for
gross dissection of vertebrate muscles. Anatomische
Anzeiger, 130(1):222-227.
Borden, W. C. 1998. Comparative myology of the
unicomfishes, Naso (Acanthuridae, Percomorpha),
with implications for phylogenetic analysis. Journal
of Morphology, 239(2): 191-224.
Borden, W. C. 1999. Phylogeny of the unicomfishes
(Naso, Acanthuridae) based on soft anatomy. Copeia,
Branson, B. A., & G. A. Moore. 1962. The lateralis com-
ponents of the acoustico-lateralis system in the sun-
fish family Centrarchidae. Copeia, 1962(1): 1-108.
Bryan, C. F. 1969. Variation in selected meristic char-
acters of some basses, Micropterus. Copeia,

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

Collar, D. C., T. J. Near, & P. C. Wainwright. 2005.
Comparative analysis of morphological diversity: does
disparity accumulate at the same rate in two lineages
of centrarchid fishes? Evolution, 59(8): 1783-1794.
Collar, D. C., & P. C. Wainwright. 2006. Discordance
between morphological and mechanical diversity in
the feeding mechanism of centrarchid fishes. Evolu-
tion, 60(12):2575-2584.
Cutwa, M. M., & R. G Turingan. 2000. Intralocality
variation in feeding biomechanics and prey use in
Archosargus probatocephalus (Teleostei, Sparidae),
with implications for the ecomorphology of fishes.
Environmental Biology of Fishes, 59:191-198.
Dean, M. N, J. J. Bizzarro, & A. P. Summers. 2007.
The evolution of cranial design, diet, and feeding
mechanisms in batoid fishes. Integrative and Com-
parative Biology, 47(1):70-81.
Dietz, P.A. 1914. Beitrage zur Kenntnis der Kiefer-und
Kiemenbogenmuskulatur der Teleostier. I. Die
Kieferund Kiemenbogenmuskeln derAcanthopterygii.
Mitteilungen Statzione zoological Neapel. 22(4)99-
Diogo, R. 2004. Muscles versus bones: catfishes as a
case study for a discussion on the relative contribu-
tion ofmyological and osteological features in phylo-
genetic reconstructions. Animal Biology, 54(4):373-
Diogo, R. 2005. Morphological Evolution, Aptations,
Homoplasies, Constraints and Evolutionary Trends:
Catfishes as a Case Study on General Phylogeny and
Macroevolution. Science Publishers Inc., Enfield, NH,
491 p.
Diogo, R., & V. Abdala. 2007. Compartive anatomy,
homologies and evolution of the pectoral muscles of
bony fish and tetrapods: a new insight. Journal of
Morphology, 268:504-517.
Diogo, R., & M. Chardon. 2000. Homologies among
different adductor mandibulae sections of teleostean
fishes, with special regard to catfishes (Teleostei:
Siluriformes). Journal of Morphology, 243:193-208.
Dorsey, R. J., A. Fluette, K. McDougall, B. A. Housen,
S. U. Janecke, G. J. Axen, & C. R. Shirvell. 2007.
Chronology of Miocene-Pliocene deposits at Split
Mountain Gorge, Southern California: a record of re-
gional tectonics and Colorado River evolution. Geol-
ogy, 35(1):57-60.
Edgeworth, F. H. 1935. The Cranial Muscles of Verte-
brates. Cambridge University Press: Cambridge, 493
Ehlinger, T. J. 1990. Habitat choice and phenotype-lim-
ited feeding efficiency in bluegill: individual differences

and trophic polymorphism. Ecology, 71(3):886-896.
Freihofer, W. C. 1963. Patterns of the ramus lateralis
accessories and their systematic significance in te-
leostean fishes. Stanford Ichthyological Bulletin,
Gabriel, M. L. 1944. Factors affecting the number and
form of vertebrae in Fundulus heteroclitus. Journal
of Experimental Zoology, 95(1): 105-143.
Gill, A. C., & R. D. Mooi. 1993. Monophyly of the
Grammatidae and of the Notograptidae, with evidence
for their phylogenetic positions among Perciformes.
Bulletin of Marine Science, 52:327-350.
Gosline, W. A. 1986. Jaw muscle configuration in some
higher teleostean fishes. Copeia, 1986(3):705-713.
Gosline, W. A. 1989. Two patterns of differentiation in
the jaw musculature of teleostean fishes. Journal of
Zoology, London, 218:649-661.
Greenwood, P. H. 1995. Preliminary studies on a
mandibulohyoid 'ligament' and other intrabuccal con-
nective tissue linkages in cirrhitid, latrid and
cheilodactylid fishes (Perciformes: Cirrhitoidei). Bul-
letin of the Natural History Museum, London (Zool-
ogy), 61(2):91-107.
Greenwood, P. H., & G V. Lauder. 1981. The protrac-
tor pectoralis muscle and the classification ofteleost
fishes. Bulletin of the Natural History Museum, Lon-
don (Zoology), 41(4):213-234.
Harris, P. M., & R. L. Mayden. 2001. Phylogenetic re-
lationships of major clades ofCatostomidae (Teleostei:
Cypriniformes) as inferred from mitochondrial SSU
and LSU rDNA sequences. Molecular Phylogenetics
and Evolution, 20(2):225-237.
Higham, T. E. 2007. Feeding, fins and braking maneu-
vers: locomotion during prey capture in centrarchid
fishes. The Journal of Experimental Biology, 210:107-
Holbourn, A., W. Kuhnt, M. Schulz, & H. Erlenkeuser.
2005. Impacts of orbital forcing and atmospheric car-
bon dioxide on Miocene ice-sheet expansion. Nature,
Hubbs, C. 1959. High incidence of vertebral deformities
in two natural populations of fishes inhabiting warm
springs. Ecology, 40(1): 154-155.
Hubbs, C. L., & R. M. Bailey. 1940. A revision of the
black basses (Micropterus and Huro) with descrip-
tions of four new forms. Miscellaneous Publications,
Museum of Zoology, University of Michigan, No. 48,
51 p. plus VI plates, 2 Maps.
Iwami, T. 2004. Comparative morphology of the adduc-
tor mandibulae musculature of notothenioid fishes
(Pisces, Perciformes). Antarctic Science, 16(1): 17-

Jayne, B. C., & G V. Lauder. 1994. Comparative mor-
phology of the myomeres and axial skeleton in four
genera of centrarchid fishes. Journal of Morphology,
Johnson, R. L., J. B. Magee, & T. A. Hodge. 2001.
Phylogenetics of freshwater black basses
(Centrarchidae: Micropterus) inferred from restric-
tion endonuclease analysis of mitochondrial DNA.
Biochemical Genetics, 39(11/12):395-406.
Kassler, T. W., J. B. Koppelman, T. J. Near, C. B.
Dillman, J. M. Levengood, D. L. Swofford, J. L.
VanOrman, J. E. Claussen, & D. P. Philipp. 2002.
Molecular and morphological analyses of the black
basses: implications for taxonomy and conservation.
Pp. 291-322 in D. P. Philipp & M. S. Ridgway, eds.
Black Bass: Ecology, Conservation, and Management.
AFS Symposium 31. American Fisheries Society,
Bethesda, MD, 724 p.
Kesner, M. H. 1994. The impact of morphological vari-
ants on a cladistic hypothesis with an example from a
myological data set. Systematic Biology, 43(1):41-57.
Koppelman, J. B., & G P. Garrett. 2002. Distribution,
biology, and conservation of the rare black bass spe-
cies. Pp. 333-341 in D. P. Philipp & M. S. Ridgway,
eds. Black Bass: Ecology, Conservation, and Man-
agement. AFS Symposium 31. American Fisheries
Society, Bethesda, MD, 724 p.
Lauder, G V. 1982. Structure and function in the tail of
the pumpkinseed sunfish (Lepomis gibbosus). Jour-
nal of Zoology, London, 197:483-495.
Lauder, G. V. 1983. Functional and morphological bases
of trophic specialization in sunfishes (Teleostei,
Centrarchidae). Journal of Morphology, 178:1-21.
Lee, D. S., C. R. Gilbert, C. H. Hocutt, R. E. Jenkins,
D. E. McAllister, & J. R. Stauffer, Jr. eds. 1980. At-
las of North American Freshwater Fishes. North
Carolina State Museum of Natural History, Raleigh,
NC, 854 p.
Leviton, A. E., R. H. Gibbs Jr., E. Heal, & C. E. Dawson.
1985. Standards in herpetology and ichthyology: Part
I. Standard symbolic codes for institutional resource
collections in herpetology and ichthyology. Copeia,
Mabee, P. M. 1988. Supraneural and predorsal bones in
fishes: development and homologies. Copeia,
Mabee, P. M. 1993. Phylogenetic interpretation of onto-
genetic change: sorting out the actual and artefactual
in an empirical case study ofcentrarchid fishes. Zoo-
logical Journal of the Linnean Society, 107:175-291.
Mabee, P. M. 1995. Evolution of pigment pattern devel-
opment in centrarchid fishes. Copeia, 1995(3):586-


McDowall, R.M. 2003. Variation in vertebral number in
galaxiid fishes (Teleostei: Galaxiidae): A legacy of life
history, latitude and length. Environmental Biology of
Fishes, 66: 361-381.
Mooi, R. D., & A. C. Gill. 1995. Association ofepaxial
musculature with dorsal-fin pterygiophores in
acanthomorph fishes, and its phylogenetic significance.
Bulletin of the Natural History Museum, London (Zo-
ology), 61:121-137.
Nakae, M., & K. Sasaki. 2004. Homologies of the ad-
ductor mandibulae muscles in Tetraodontiformes as
indicated by nerve branching patterns. Ichthyological
Research, 51:327-336.
Near, T. J., T. W. Kassler, J. B. Koppelman, C. B.
Dillman, & D. P. Philipp. 2003. Speciation in North
American black basses, Micropterus, (Actinopterygii:
Centrarchidae). Evolution, 57(7): 1610-1621.
Near, T. J., D. I. Bolnick, & P. C. Wainwright. 2005.
Fossil calibrations and molecular divergence time es-
timates in centrarchid fishes (Teleostei:
Centrarchidae). Evolution, 59(8): 1768-1782.
Nelson, J. S., 2006. Fishes of the World. 4th edition.
John Wiley & Sons, Inc., Hoboken, NJ, 601 p.
Nelson, J. S., E. J. Crossman, H. Espinosa-Perez, L. T.
Findley, C. R. Gilbert, R. N. Lea, & J. D. Williams.
2004. Common and Scientific Names of Fishes of
the United States, Canada, and Mexico. AFS Special
Publication 29. American Fisheries Society, Bethesda,
MD, 386 p.
Norton, S. F. 1995. A functional approach to
ecomorphological patterns of feeding in cottid fishes.
Environmental Biology of Fishes, 44:61-78.
Norton, S. F., & E. L. Brainerd. 1993. Convergence in
the feeding mechanics of ecomorphologically similar
species in the Centrarchidae and Cichlidae. Journal
of Experimental Biology, 176:11-29.
Pasztor, V. M., & H. Kleerekoper. 1962. The role of the
gill filament musculature in teleosts. Canadian Jour-
nal of Zoology, 40:785-802.
Pekar, S. F., & R. M. DeConto. 2006. High-resolution
estimates for the early Miocene: evidence for a dy-
namic ice sheet in Antarctica. Palaeogeography,
Palaeoclimatology, Palaeoecology, 231(1-2):101-109.
Philipp, D. P., & M. S. Ridgway, eds. 2002. Black Bass:
Ecology, Conservation, and Management. AFS Sym-
posium 31. American Fisheries Society, Bethesda, MD,
724 p.
Potthoff, T. 1984. Clearing and staining techniques. Pp.
35-37 in G Moser, W. J. Richards, D. M. Cohen, M.
P. Fahay, A. W. Kendall & S. L. Richardson, eds.
Ontogeny and Systematics of Fishes. ASIH Special

BORDEN and COBURN: Striated Muscles of the Black Basses (Micropterus, Centrarchidae)

Publication, no. 1. American Society of Ichthyologists
and Herpetologists, Gainesville, FL, 760 p.
Prothero, D. R., L. C. Ivany, & E. A. Nesbitt. 2003.
From Greenhouse to Icehouse: The Marine Eocene-
Oligocene Transition. Columbia University Press, New
York, 541 p.
Raikow, R. J., A. H. Bledsoe, B. A. Meyers, & C. J.
Welsh. 1990. Individual variation in avian muscles and
its significance for the reconstruction of phylogeny.
Systematic Zoology, 39:362-370.
Ramsey, J. S. 1975. Taxonomic history and systematic
relationships among species ofMicropterus. Pp. 67-
75 in R. H. Stroud & H. Clepper, eds. Black Bass
Biology and Management. Sport Fishing Institute,
Washington, D.C., 534 p.
Roe, K. J., P. M. Harris, & R. L. Mayden. 2002. Phylo-
genetic relationships of the genera of North Ameri-
can sunfishes and basses (Percoidei: Centrarchidae)
as evidenced by the mitochondrial cytochrome b gene.
Copeia, 2002:897-905.
Schultze, H.-P., & G. Arratia. 1989. The composition of
the caudal skeleton of teleosts (Actinopterygii:
Osteichthyes). Zoological Journal of the Linnean So-
ciety, 97:189-231.
Scott, W. B., & E. J. Crossman. 1973. Freshwater Fishes
of Canada. Fisheries Research Board of Canada,
Bulletin 184. Ottawa, ON, 966 p.
Shufeldt, R.W. 1900. The skeleton of the black bass.
Extracted from the U. S. Fish Commission Bulletin
for 1899:311-320, and plate 44.
Springer, V. G., & G. D. Johnson. 2004. Study of the
dorsal gill-arch musculature ofteleostome fishes, with
special reference to the Actinopterygii. Bulletin of the
Biological Society of Washington, 11:1-260.2 Volumes.
Stiassny, M. L. J. 1992. Atavisms, phylogenetic charac-
ter reversals, and the origin of evolutionary novelties.
Netherlands Journal of Zoology, 42(2-3):260-276.
Sullivan, J. P., J. G Lundberg, & M. Hardman. 2006. A
phylogenetic analysis of the major groups ofcatfishes
(Teleostei: Siluriformes) using rag] and rag2 nuclear
gene sequences. Molecular Phylogenetics and Evo-
lution, 41:636-662.
Taylor, W. R., & G. C. Van Dyke. 1985. Revised proce-
dures for staining and clearing small fishes and other
vertebrates for bone and cartilage study. Cybium,
Thorsen, D. H., & M. W. Westneat. 2005. Diversity of
pectoral fin structure and function in fishes with
labriform propulsion. Journal of Morphology, 263:133-
Trautman, M. B. 1981. The Fishes of Ohio. Revised
edition. Ohio State University Press, Columbus, OH,

782 p.
Wainwright, P. C., M. E. Alfaro, D. I. Bolnick, & C. D.
Hulsey. 2005. Many-to-one mapping of form to func-
tion: a general principle in organismal design? Inte-
grative and Comparative Biology, 45:256-262.
Wainwright, P. C., & G V. Lauder. 1992. The evolution
of feeding biology in sunfishes (Centrarchidae). Pp.
472-491 in R. L. Mayden, ed. Systematics, Histori-
cal Ecology, and North American Freshwater
Fishes. Standford University Press, Stanford, CA, 969
Wainwright, P. C., & B. A. Richard. 1995. Predicting
patterns of prey use from morphology of fishes. En-
vironmental Biology of Fishes, 44:97-113.
Wainwright, P. C., & S. S. Shaw. 1999. Morphological
basis of kinematic diversity in feeding sunfishes. The
Journal of Experimental Biology, 202:3101-3110.
Wiens, J. J. 1999. Polymorphism in systematics and com-
parative biology. Annual Review of Ecology and Sys-
tematics, 30:327-362.
Wiens, J. J. 2001. Character analysis in morphological
phylogenetics: problems and solutions. Systematic
Biology, 50(5):689-699.
Wiens, J. J., & M. R. Servedio. 1997. Accuracy of phy-
logenetic analysis including and excluding polymor-
phic characters. Systematic Biology, 46(2):332-345.
Wiley, E. 0. 1992. Phylogenetic relationships of the
Percidae (Teleostei, Perciformes): a preliminary hy-
pothesis. Pp. 247-267 in R. L. Mayden, ed. System-
atics, Historical Ecology, and North American Fresh-
water Fishes. Standford University Press, Stanford,
CA, 969 p.
Winterbottom, R. 1974a. A descriptive synonymy of the
striated muscles of the Teleostei. Proceedings of the
Academy of Natural Sciences of Philadelphia,
Winterbottom, R. 1974b. The familial phylogeny of the
Tetraodontiformes (Acanthopterygii: Pisces) as evi-
denced by their comparative myology. Smithsonian
Contributions to Zoology, 155:1-201.
Winterbottom, R. 1993. Myological evidence for the
phylogeny of recent genera of surgeonfishes
(Percomorpha, Acanthuridae), with comments on the
Acanthuroidei. Copeia, 1993(1):21-39.
Wintzer, A. P., & P. J. Motta. 2005. Diet-induced phe-
notypic plasticity in the skull morphology of hatchery-
reared Florida largemouth bass, Micropterus
salmoides floridanus. Biology of Freshwater Fish,
Wu, K-Y., & S-C. Shen. 2004. Review of the teleostean
adductor mandibulae and its significance to the sys-
tematic positions of the Polymixiiformes,


Lampridiformes, and Triacanthoidei. Zoological Stud-
ies, 43(4):712-736.
Yabe, M. 1985. Comparative osteology and myology of
the superfamily Cottoidea (Pisces: Scorpaeniformes),
and it phylogenetic classification. Memoirs of the
Faculty of Fisheries, Hokkaido University, 32:1-130.
Zanazzi, A., M. J. Kohn, B. J. MacFadden, & D. 0.
Terry, Jr. 2007. Large temperature drop across the
Eocene-Oligocene transition in central North America.
Nature, 445(7128):639-642.

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs