(DRAFT) - Taxonomy
Species conch, queen
Species Id M060165
Date 26 AUG 96
TAXONOMY
NAME - conch, queen
OTHER COMMON NAMES - queen conch and pink conch
ELEMENT CODE -
CATEGORY - Aquatic Molluscs
PHYLUM AND SUBPHYLUM - Mollusca,
CLASS AND SUBCLASS - Gastropoda, Prosobranchia
ORDER AND SUBORDER - Mesogastropoda,
FAMILY AND SUBFAMILY - Strombidae,
GENUS AND SUBGENUS - Strombus,
SPECIES AND SSP - gigas,
SCIENTIFIC NAME - Strombus gigas
AUTHORITY - Linnaeus
TAXONOMY REFERENCES - 186 and 213
COMMENTS ON TAXONOMY -
The common names, queen or pink conch, come from the beautiful color
and graceful lines of the shell. There are 55 species of Strombus conchs,
six of which occur in Caribbean and Florida waters *213*.
Taxonomy - 1 (DRAFT) - Status
Species conch, queen
Species Id M060165
Date 26 AUG 96
STATUS
Coded Status
Commercial
Existing, FMP exists
Commercial/consumption
Commercial/bait
Other federal or state designation
See Comments
REFERENCES FOR STATUS - 213
COMMENTS ON STATUS -
Conch is one of the most important export fisheries in the Caribbean *213*.
In 1985, Florida banned all harvest, killing, molestation, harming or
mutilation of queen conch in Florida waters. Beginning in December 1986,
the rule was extended so now harvest by all persons in Florida-registered
vessels in federal waters contiguous to Florida waters is banned. As of
1989, it is unlawful to take or harvest any queen conch from the land or
waters of Florida or to possess or transport any queen conch so taken or
harvested *213*.
The soft parts of the body are used for fish bait or are discarded *213*.
The well-developed foot muscle of the queen conch provides the sweet white
meat so highly prized. Excluding the shell, 35% of the animal's weight is
marketable meat *213*.
Status - 1 (DRAFT) - Distribution
Species conch, queen
Species Id M060165
Date 26 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
REFERENCES FOR HABITAT - 213
LAND USE -
Water
Atlantic Ocean Coastal Waters
REFERENCES FOR LAND USE - 213
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Marine AB.
Marine RF.
Marine RF1
Marine OW0
REFERENCES FOR NWI - 213
COMMENTS ON HABITAT ASSOCIATIONS -
Adults are found most often in seagrass meadows and hard-bottom
communities, but may also be seen on the sandy sea floor, coral rubble and
reefs.
The larval stage drifts and swims in the ocean currents, feeding on
phytoplankton *213*.
ANIMAL/PLANT SPECIES ASSOCIATIONS -
pink cardinal fish
slipper limpets
REFERENCES FOR SPECIES ASSOCIATIONS - 213
COMMENTS ON SPECIES ASSOCIATIONS -
Other sea creatures often share the large shell of the conch. Pink cardinal
fish, or conchfish, may live in the space between the shell and the animal.
As many as five may be present. A small crab also lives commensally with
the conch, making its home wedged between the shell and the foot. Slipper
limpets are sometimes found securely attached to the shell or operculum
*213*.
Habitat Associations - 1 (DRAFT) - Food Habits
Species conch, queen
Species Id M060165
Date 26 AUG 96
FOOD HABITS
TROPHIC LEVEL -
DETRITIVORE
HERBIVORE/GRAZER
REFERENCES FOR TROPHIC LEVEL - 213
LIFESTAGE FOOD FOOD PART
General Microorganisms Not Applicable
General Bacteria Not Applicable
General Algae Not Applicable
General See Comments; Food Not Applicable
Adult Microorganisms Not Applicable
Adult Algae Not Applicable
Adult Detritus - Organic Not Applicable
Adult See Comments; Food Not Applicable
Juvenile Microorganisms Not Applicable
Juvenile Algae Not Applicable
Juvenile Detritus - Organic Not Applicable
Juvenile See Comments; Food Not Applicable
Larva Microorganisms Not Applicable
Larva Phytoplankton Not Applicable
Larva See Comments; Food Not Applicable
REFERENCES FOR GENERAL FOOD - 213
REFERENCES FOR ADULT FOOD - 213
REFERENCES FOR JUVENILE FOOD - 213
REFERENCES FOR LARVAE FOOD - 213
COMMENTS ON FOOD -
The snout-like mouth can be extended to graze on small algae growing on
rocks and dead coral, or to ingest algae- or bacteria- covered sand grains
*213*.
All species of stromboid conchs in the Caribbean are herbivore and detritus
feeders *213*.
COMMENTS ON ADULT FOOD -
Adults feed on algae and algal detritus *213*.
COMMENTS ON JUVENILE FOOD -
Juvenile conchs, called "rollers", graze on the algae attached to seagrasses
and detritus *213*.
COMMENTS ON LARVAE FOOD -
Veligers feed on phytoplankton drifting in the sea. Their ciliated lobes
capture tiny, single-celled plants *213*.
Food Habits - 1 (DRAFT) - Environment Associations
Species conch, queen
Species Id M060165
Date 26 AUG 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Water Depth Preference: Specified in Comments
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 213
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
Queen conchs are found in depths down to nearly 500 feet, but are most
abundant in waters ranging from the shallows to 70 feet *213*.
Environment Associations - 1 (DRAFT) - Life History
Species conch, queen
Species Id M060165
Date 26 AUG 96
LIFE HISTORY
DESCRIPTION
The body consists of a black-speckled, long and narrow foot, a "head" with
colorful yellow eyes on the end of two protruding stalks, and a snout-like
probosis between them, plus a pair of slender, sensitive tentacles. The
orange or yellow mantle resembles a close-fitting cover enclosing the foot
and head. The respiratory organs are feathery gill combs in the mantle
which remove oxygen from the water. Eye development in queen conch is more
complex and keener than most other gastropods *213*.
The foot bears a horny, sickle-shaped operculum that digs into the bottom as
the conch hurtles itself forward. It moves about half its body length with
each leap. The operculum is too small and curved to seal the shell opening
completely when the animal retreats into its shell, so the conch is not able
to "close" its shell as well as other snails do. The operculum is used
mainly to assist in locomotion and righting the shell when it is turned
over *213*.
An adult conch has a "heavy" shell with a broad, flaring lip. A blunt crown
of spines projects from each whorl of the spiral shell as they descend from
the apex. The shell coils to the right when viewed with the apex nearest
the eye *213*.
The broad, flaring lip of a mature conch has a "stromboid notch," which is a
deep, upward ripple of shell at the end opposite the apex. When the animal
emerges from its shell, one eyestalk protrudes from this notch and the other
from the opening at the end of the spiral column. The living shell is
covered with a brown papery covering called the periostracum, which scales
off when the shell is dried. Ther periostracum, which collects silt,
bacteria and algae, contributes to the mossy-rock look of conchs resting on
the sea floor *213*.
Young conch shells, called "rollers", do not have the flaring lip of adults.
The shell is more fragile, the spines are well-developed, more pointed and
not yet blunted. When the lip is first laid down, it is thin and delicate.
Boring sponges and other creatures can cause the lip to crumble. The conch
then directs its energies to renew and repair the lip, so it becomes
thicker. As time goes by, the animal continues to strengthen its shell and
flaring lip from the inside of the shell, increasing the shell thickness and
decreasing the shell volume. The shell is composed mainly of calcium
carbonate, excreted by the mantle as a fluid which hardens as crystals*213*.
GROWTH AND MATURATION
Queen conchs are among the largest gastropods in the sea, though males tend
to be slightly smaller than females. Shells measuring up to 12 inches have
been found. The shell length increases at an average rate of nearly three
inches (75 mm) a year in its active growing stage. With maturity, the shell
thickens and the increase in length slows or ceases *213*.
FEEDING
The snout-like mouth can be extended to graze on small algae growing on
rocks and dead coral, or to ingest algae- or bacteria- covered sand grains
*213*.
EGGS
Egg masses are excreted as tightly wound gelatinous strings of capsules
Life History - 1 (DRAFT) - Life History
Species conch, queen
Species Id M060165
Date 26 AUG 96
containing more than a half-million embryos. The tube is folded back and
forth on itself, producing a long, slightly curved mass. From 70 to more
than 129 feet of tube strands may be extruded, at a rate of about five feet
per hour. Conchs spawn mainly in the warmer months, although egg masses have
been observed throughout the year. Larval veligers emerge from the egg case
after three to five days *213*.
LARVAE
The newly hatched , microscopic larva, called a veliger, has two ciliated
"wings" (lobes) used for swimming. The veliger has a tiny, transparent
shell (protoconch) which will eventually form the familiar shell. By the
sixth day of life, the veliger has four wing-like lobes; by the twelfth,
six. It drifts and swims in the ocean currents, feeding on phytoplankton
Velagers may travel great distances, moved by ocean currents. The currents
disburse the larvae throughout their geographic range *213*.
After 21 days, the veliger settles to the sea floor, the lobes disappear,
and the "foot" and proboscis development continues. It takes about a month
to develop into a shelled animal that begins to resemble the adult form.
JUVENILE
Queen conchs measure about three inches long at one year and five inches by
the second year. Juvenile conchs, called "rollers", graze on the algae
attached to seagrasses and detritus *213*.
The broad, flaring lip of the shell begins to develop after two-and-a-half
to three years, when it is about eight or ten inches long *213*.
ADULTS
Adults may wander for miles. Tagged adults have moved as much as one mile
over a two month period, and more than 700 yards in a week. They gather in
large colonies in shallow water in the summer through the fall months to
spawn. The animal reaches sexual maturity only after the lip is
well-developed; in terms of meat production, this stage is the optimum time
for harvest. From this point, the shell does not grow significantly in size
and length; the conch energies are directed to strengthening the shell and
lip, so it becomes thicker and heavier and the space occupied by the animal
actually becomes smaller. Older, heavier conchs were once believed to be a
different species and were called "sambas" *213*.
REPRODUCTION
Adults gather in large colonies in shallow water in the summer through the
fall months to spawn. Queen conchs mate in shallow waters in sandy areas
behind the reefs. The sexes are separate. Fertilization is internal.
During mating the male sits behind the female, depositing sperm via the
black, spade-like verge which is inserted into the female. The female
retains sperm for several weeks, releasing it to fertilize the eggs when
they are laid. Some may spawn as many as six or eight times a season *213*.
PREDATION
In the larval stages, queen conchs are preyed on by other small, swimming
creatures. Juveniles are eaten by crabs, sharks and rays, loggerhead
turtles, groupers and snappers, and octopus. After two years man is
probably the most important predator, fishing for conch to the point that
some Caribbean populations are threatened *213*.
Life History - 2 (DRAFT) - Life History
Species conch, queen
Species Id M060165
Date 26 AUG 96
FEEDING HABITS
The conch digestive system includes a crystalline style, a flexible rod
about five inches long composed of a microprotein gel. As the style rotates
against the gastric shield of the digestive tract, enzymes are released that
are capable of digesting the cellulose of the plants consumed. In addition,
a salivary gland and esophageal pouches digest cellulose *213*.
LIFE HISTORY CODES -
Foraging Strategy: Grazing
Foraging Sites: Herbaceous vegetation
Average Number of Offspring/Reproductive Effort: Grea
Number of Broods/Litters (Reproductive Efforts) Per Ye
REFERENCES FOR LIFE HISTORY- 213
Life History - 3 (DRAFT) - Management Practices
Species conch, queen
Species Id M060165
Date 26 AUG 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Regulating harvest of species being described
Beneficial Prohibiting harvest of species being described
Existing Regulating harvest of species being described
Existing Prohibiting harvest of species being described
Existing Mariculture activities
Existing Other management practices [specified in comments]
REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 213
REFERENCES FOR EXISTING MANAGEMENT PRACTICES - 213
COMMENTS ON MANAGEMENT PRACTICES -
MANAGEMENT PROBLEMS
There have been many management problems in the efforts to protect this
significant fishery. In the Bahamas, the fishery is a diffuse, "cottage"
fishery, with many small, independent businesses involved, difficult to
oversee. Shell disposal is a problem; cleaned shells, dumped at the docks,
can clog harbors. (Nassau, Bahamas, imposes fines for shell dumping.) In
other areas, the fishery is run by fishing cooperatives with large
processing plants. All conch are cleaned at sea and only the body brought
ashore *213*.
The animal reaches sexual maturity only after the lip is well-developed; in
terms of meat production, this stage is the optimum time for harvest *213*.
FISHING GEAR
In the Caribbean, queen conchs were once fished from dinghies by scanning
the bottom with glass-bottom buckets, then retrieving the animals with long,
hooked poles. Now divers use SCUBA and snorkeling gear to find conchs.
They are often brought to port live. They are cleaned by knocking a hole
between the third and fourth whorl of the spire, inserting a knife to cut
the animal free from the shell, and then pulling it out. The soft parts of
the body are used for fish bait or discarded *213*.
REGULATIONS
Venezuela, Belize and Puerto Rico now have seasons closed to conch harvest.
These shellfish have been so extensively harvested that their numbers
have severely declined. In 1978, Florida declared a moratorium on commercial
fishing. In 1985, Florida banned all harvest, killing, molestation, harming
or mutilation of queen conch in Florida waters. Beginning in December 1986,
the rule was extended so now harvest by all persons in Florida-registered
vessels in federal waters contiguous to Florida waters is banned. As of
1989, it is unlawful to take or harvest any queen conch from the land or
waters of Florida or to possess or transport any queen conch so taken or
harvested *213*.
FARMING POTENTIAL
There has been great interest throughout the Caribbean in breeding and
rearing conchs in aquaculture systems, especially since 1982. Several
Management Practices - 1 (DRAFT) - Management Practices
Species conch, queen
Species Id M060165
Date 26 AUG 96
hatcheries have been established, but mass-rearing of conchs has had mixed
success *213*.
STOCKING
In 1986, the Florida Department of Natural Resources field station in
Marathon, Florida, initiated a stock assessment program and a research
effort to determine the feasibility of queen conch stocking in Florida as a
management tool. To date, small-scale efforts reported in the literature
have indicated massive mortality of hatchery-reared juveniles released in
the field. During 1988-1989, to test out-door facilities for grow-out and
production of larger juveniles, hatchery-reared conchs were raised to a size
of five inches. Much work is yet to be done to determine whether stock
enhancement is, in fact, necessary and feasible. To protect native stock,
permits will eventually be required before any hatchery animals can be
released into the wild. *213*.
Management Practices - 2 (DRAFT) - References
Species conch, queen
Species Id M060165
Date 26 AUG 96
References
186 * Turgeon, D.D., A.E. Bogan, E.V. Coan, W.K. Emerson, W.G.
Lyons, W.L. Pratt, C.F.E. Roper, A. Scheltema, F.G. Thompson,
J.D. Williams. 1988. Common and scientific names of aquatic
invertebrates from the United States and Canada: mollusks.
American Fisheries Society Special Publication 16. (ed.):277.
213 * Stewart, V.N. 1990. Sea-Stats - A summary of information
and statistics on Florida's marine organisms and the marine
environment. Queen Conch. (14) (ed.). FL Department of Natural
Resources St. Petersburg, FL:10.
References - 1