FI* pjSH A*
q~ K 4e
C -* ~ n
Department of Planning and Natural Resources
Division of Fish and Wildlife
U.S.V.I. Animal Fact Sheet #19
The beautiful shell of the queen conch (Strombus
gigas) is an enduring symbol for the USVI, as it is for the
whole Caribbean. Among images, the foremost is the "call
to freedom" that was sounded by the blowing of a conch
horn, signifying an end to slavery during the Danish
colonial era. But queen conchs, and their shells, have been
utilized throughout the history of our islands. The earliest
inhabitants Arawak, Taino, and Caribe Indians fashioned
jewelry from conch shells, used them for tools, cookware,
horns, and even as building materials. The first explorers
returned home with the conch shells and they were quickly
adopted as a standard decorative item for European homes.
Today, the beauty of conch shells still captivates tourists
who purchase them as mementos of their visit.
Because of their exquisite taste and large size, queen
conchs have always been an important food in the USVI.
Today, conch meat (derived from the conch's foot) is used
in many traditional dishes like pates, fritters and chowders.
Queen conch meat is in high demand, with a market price
of about $6.00 per pound. For this reason, the queen conch
supports a commercial fishery of scuba and free divers who
harvest conch by hand. The queen conch fishery makes an
important contribution to our local economy.
Reaching over 12 inches in shell length, but averaging
6-9 inches, the queen conch is among the largest marine
snails in the world older adults may exceed 5 pounds! The
large, thick shell has blunt spikes that radiate from a central
spire. The shell flares sideways into a "lip" on the shells of
older conchs. Inside, the shell color is a lustrous pink to
red. An orangish layer (called the periostracum) coats the
shell's exterior, though it is usually hidden beneath a layer
of algae and sediments. With age, the periostracum slowly
erodes away, being absent from shells of the oldest conchs.
Hidden within the sturdy shell is the conch itself. The
queen conch has a mottled gray head with large proboscis
(mouth) for feeding on algae. Two well-developed yellow
eyes rest on the ends of eyestalks, each stalk bearing one
short sensory tentacle. Attached to the foot is a long claw-
like operculum which is used for propulsion, much like a
pole-vault. Through a series of awkward leaps and tumbles,
the queen conch slowly moves forward. A yellow-orange
mantle is pressed against the shell continuously polishing
the surface and secreting more shell material. Rarely (about
1 in 10,000 conchs), the mantle secretes shell around an
embedded object like a sand grain, forming a conch pearl.
The queen conch is one of five conch species found in
the USVI. The queen conch is distinguished by its large
size, blunt shell-spikes, orange mantle, and mottled gray
head. Our four other conchs (all in the genus Strombus) are
distinguished as follows: the milk conch (S. costatus) has a
creamy color along the inside of its shell and a green head;
the hawkwing conch (S. raninus) has a knobby brown and
purple shell with a reddish interior; the roostertail conch (S.
gallus) has a distinctive "roostertail" extending rearward
from shell lip; the West Indian fighting conch (S. pugilis) is
smaller (-4 inches) and the shell opening is deep orange.
The queen conch is an invertebrate from the phylum
Mollusca (meaning soft body) a group that includes
snails, chitons, clams, octopuses, and squids. Conchs are
classified together with all other snails as gastropods
(stomach feet). The queen conch belongs to the subclass
Prosobranchia and family Strombidae. Their genus name
Strombus means "spiral shell" and their species name gigas
Distribution and Habitat
The range of the queen conch extends from southern
Florida and Bermuda to the Bahamas, stretching southward
throughout the Caribbean. Queen conchs generally occur in
waters less than 100 feet deep although they are
occasionally found at depths greater than 200 feet.
Adult queen conchs occur in habitats where algae (their
preferred food) abound such as hardbottom or sandy algal
plains, rubble areas, and seagrass beds. Occasionally they
forage in coral reef habitats too. Their habitat preference
changes during the course of their lifetime (see below) and
they migrate during reproduction. Despite their slow speed,
conchs may travel large distances (tens of miles) during
their foragings and migrations, making their exact locations
difficult to predict from one year to the next.
Growth and Reproduction
Queen conchs have been reported to live for 40 years
(in Bermuda), although 6-15 years may be more typical.
The architecture of a queen conch shell reflects its age and
sexual maturity. Young, sexually immature conch have thin
shells that quickly elongate up to 3 inches per year but
lack a flared lip. As a conch reaches sexual maturity
(usually in its third year) and reaches a length of ~9 inches,
shell growth changes permanently: energy is devoted to
shell thickening, and the opening of the shell flares into a
distinct lip. In mature conch, both shell and lip continue to
thicken throughout life while shell length changes little.
In the spring or early summer, mass conch migrations
from deep to shallow coincide with annual reproduction.
After mating with males, the females lay 6-inch egg masses
composed of thin tubes over 100 feet long. Within the egg
masses, up to half a million conch embryos develop. The
embryos hatch as tiny free-floating larvae called veligers,
which drift in the open ocean for 3-4 weeks. Some veligers
survive the voyage to settle down in quiet nearshore waters
- especially shallow seagrass beds, algal plains, and sandy
areas. There, they transform into small conch and spend
much of their first year buried under sand and sediments,
emerging at night to feed. In their second year, when conch
have reached 3-6 inches in length, they emerge and move
into shallow seagrass and sandy habitats. From here they
may progress to deeper habitats with age.
Queen conchs are herbivorous, feeding primarily on
algae, but also on decaying plant and animal material called
detritus. Frequently, they graze in seagrass beds, eating
algae that grow on blades of seagrass.
Among the predators of queen conch, man is clearly
the most significant in some places queen conchs have
become rare due to over-harvesting. Quite a few predators
eat juvenile conch: fish, such as porcupinefish (Diodon
hystrix) and permit (Trachinotusfalcatus), and spiny
lobsters (Panulirus argus) prey on juveniles, as do a variety
of crabs, sharks, rays and snails. Adult conchs, owing to
their larger size and thicker shells, have fewer predators
(aside from humans). These include horse conchs, octopus,
and loggerhead sea turtles.
In recent decades, declines in USVI conch populations
have led to serious concerns about their conservation.
Territorial and federal regulations have been enacted to
hel ueen conch stocks recover to their former abundance.
of 9 inches
To protect immature individuals, queen conch must be
a minimum of 9 inches in shell length (from spire to distal
end as shown above) or 3/8-inch lip thickness [a measuring
gauge is available from DFW]. Commercial fishermen are
limited to 150 conchs per day while recreational fishermen
(for personal use) can take no more than 6 conchs per day.
Conch must be landed whole in their shells. There is a
closed season each year (July 1st to September 30th), when
queen conch cannot be harvested, to ensure successful
conch reproduction. Undersized conch shells and their meat
cannot be sold. Imported conch must have a CITES export
permit and clear at the port of Miami.
Awareness of and adherence to regulations is one
means to preserve queen conch populations. Protection of
essential habitats, especially the conch nursery areas found
within our near shore waters, will be equally important to
ensure conch for future generations.
References for this article are available upon request from
DFW. For more information on this or other animals in the
USVI please visit our web site at:
WRITTEN BY WES TOLLER AND KEMIT-AMON LEWIS
IN 2003. THIS PUBLICATION WAS PRODUCED WITH
FUNDS FROM THE WILDLIFE CONSERVATION AND
RESTORATION PROGRAM (WCRP).
FOR MORE INFORMATION CONTACT
DIVISION OF FISH AND WILDLIFE
6291 ESTATE NAZARETH, 101,
ST. THOMAS, VI 00802
PHONE 340-775-6762 FAX 340-775-3972
45 MARS HILL, ST. CROIX, VI 00840
PHONE 340-772-1955 FAX 340-772-3227