,,0 flSH A*
Department of Planning and Natural Resources
Division of Fish and Wildlife
U.S.V.I. Animal Fact Sheet #14
The spiny lobster, Panulirus argus, could easily be an
emblem for the plentifulness of our Virgin Islands
nearshore waters. Their large size (averaging 1 to 3 lbs but
reaching over 15 lbs) and delectable taste make spiny
lobsters a valuable food for locals and tourists alike. For
this reason, spiny lobsters support an important local
commercial fishery. Recreational fishers also pursue spiny
lobsters. And pleasure divers enjoy them too a close-up
encounter with a big spiny lobster can add a memorable
thrill to any dive.
True to their name, spiny lobsters are indeed spiny,
with many stout spines arising from the hard shell that
covers their body (called an exoskeleton). The two largest
spines or "horns" project forward over their eyes. Spiny
lobsters have five pairs of walking legs, but they lack the
large claws of some other lobster species from colder
climates. Generally, lobsters use their legs to move about
the seafloor. When startled, however, a spiny lobster uses
powerful flips of its muscular tail to make a rapid
backwards escape. A large pair of antennae also assists
with self-defense. Spiny lobsters will wave their antennae
at intruders, often maintaining contact so as to keep the
enemy at a safe distance. Two smaller forked antennae,
called antennules, are used for taste, as are the tips of the
legs (imagine tasting food with your feet!). Body coloration
is variable, but is usually orange-brown on back fading to
tan on the sides. The tail fan has distinct dark bands.
Scientists compare lobsters on the basis of size,
typically using a measure called carapace length. The
carapace is the fused and hard-shelled back portion of the
lobster that extends from the eyes to the first flexible
segment of the tail.
Although at least seven species of lobsters may be
found in waters of the USVI, spiny lobsters grow the
largest, and adults are usually easy to recognize. Spiny
lobsters have two long antennae, whereas slipper lobsters
(Scyllarides, Arctides, Parribacus) and copper lobsters
(Palinurellus gundlachi) have short antennae.
Occasionally, you might encounter one of two closely
related species: the spotted spiny lobster (Panulirus
guttatus) or more rarely, the olive-green colored smoothtail
spiny lobster (Panulirus laevicauda). Both of these species
have many more white spots than Panulirus argus, notably
with spots extending onto their legs. In contrast, spiny
lobsters have only stripes on their legs (no spots), and only
a few white spots on their carapace and tail.
There is no consensus on the best common name to use
for Panulirus argus. Some scientists call them Caribbean
spiny lobsters; others call them West Atlantic spiny lobsters
or Florida spiny lobsters. Here, we call them spiny lobsters.
Most locals simply use the name lobster, or in Spanish
Lobsters are invertebrates (animals without backbones)
that belong to the subphylum Crustacea. This large and
diverse group includes many familiar crabs and shrimps.
All lobsters are classified in the order Decapoda (meaning
ten legs). Spiny lobsters belong to the family Palinuridae,
with about 49 species worldwide.
Spiny lobsters occur in nearshore waters throughout
the Caribbean Sea, the Bahamas, and Bermuda. They
inhabit coastal waters of the Americas, from North
Carolina southward to Brazil. Occasionally, spiny lobsters
have been caught in the Gulf of Guinea (western Africa),
but they don't seem to form stable populations there. In
almost every place that spiny lobsters occur, they are
harvested by fishers, thereby supporting fisheries and
making a contribution to local economies. In Florida, for
example, spiny lobsters are perhaps the single most
economically important marine species.
Life History & Habitat
To appreciate the biology of spiny lobsters, one should
first realize that their life history is a complex cycle with
five distinct phases: adult, egg, phyllosome larva, puerulus
larva, and juvenile. Each phase occurs in a different habitat.
A female lobster becomes mature at 2-3 years of age
(carapace length of 3 /4 inches). She mates with a mature
male, who deposits two sticky gray patches of sperm
(known as "tar spots" or tar patches") on her belly. Eggs
are fertilized as the female lays them, but she doesn't
release them. Rather, she holds the bright orange-red eggs
in a bundle on the underside of her tail. After 2-4 weeks of
development, the eggs, now brownish colored, are ready to
Females usually move to deeper waters for releasing
their young. Tiny lobster larvae called phyllosome larvae
(which means leaf-shaped body) hatch from the eggs. The
phyllosome phase is pelagic larvae drift in the open ocean
at the mercy of currents. The phase may last from 6 months
to over a year. Obviously, spending so much time adrift can
result in larvae being carried a very long way perhaps
thousands of miles. This raises some serious questions
about where our lobsters come from. Scientists are still
trying to determine how far the larvae drift, and how often
they return to their place of origin.
Phyllosoma Larva Lobster Pueruli
At some point during their pelagic phase, lobster larvae
change into a postlarval form known as a puerulus.
Although still tiny (- 1/4-inch carapace length) and mostly
transparent, the puerulus phase actively swims towards
shore, seeking out habitats that are heavily vegetated with
algae or seagrass. They prefer one particular species of red
algae called Laurencia. Because such vegetated areas occur
in mangrove lagoons, estuaries, seagrass beds, and
protected shallow water bays, these areas are critical
nursery grounds for young spiny lobsters.
Shortly after settling into suitable habitat, the puerulus
changes into a juvenile, now resembling an adult lobster in
miniature form. As juveniles grow and mature, they move
from shallow nursery habitats to hardbottom habitats in
progressively deeper waters where they will live as adults.
During the spawning season, adult spiny lobsters are
known to move towards deeper waters, such as shelf-edge
reefs. In Florida and the Bahamas, spiny lobsters also make
spectacular seasonal migrations (usually in the Fall), where
hundreds of lobsters line up head-to-tail. With the antennae
of the one behind touching tail of the one ahead, they move
en masse towards deeper waters. Although reported in the
USVI, such mass migrations appear to be only rarely
Ecology & Behavior
Adult spiny lobsters are nocturnal and gregarious. By
daylight, they generally remain hidden in dens that are
formed by caves, crevices, ledges, coral heads or large
sponges. Lobster dens are shelters from predators, and
spiny lobsters seem to prefer sharing their dens with others.
At around sunset, they emerge from shelters to forage alone
away from their dens. Sometimes, they can cover large
distances (over 200 yards) in search of prey, their
wanderings often taking them into nearby areas of reef,
sand and seagrass habitats.
Ecologically, adult spiny lobsters are important
"keystone" predators. That is, their feeding controls the
populations of the many different species that they eat.
Spiny lobsters feed primarily on snails, clams, small crabs
and urchins, using their strong jaws to crush and open the
shells of their prey. Sometimes spiny lobsters will also
scavenge meals (such as a dead fish) but they generally
prefer live prey.
Juvenile spiny lobsters suffer from high predation,
falling victim to many different fish species, octopus, and
crabs. However as they get larger, fewer predators can
handle such a spiny meal. The most important predators on
adult spiny lobsters are large groupers, like the goliath
grouper jewfishh), sharks, moray eels, and loggerhead sea
Federal and territorial regulations protect spiny
lobsters. In the USVI, it is illegal to harvest spiny lobsters
that measure less than 3 V2 inch carapace length (89 mm).
Divers may catch lobsters by hand or with a snare only -
spearing or gigging is never allowed. Commercial fishers
may catch lobsters in traps. Poisons (such as bleach)
cannot be used to catch lobsters or any other marine
species. Additionally, female lobsters bearing eggs cannot
be harvested. Put "berried" females back so that they can
hatch their eggs.
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 IN 2003.
THIS PUBLICATION WAS PRODUCED WITH
FUNDS FROM THE WILDLIFE
CONSERVATION AND RESTORATION
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