(DRAFT) - Taxonomy
Species grouper, Nassau
Species Id M010412
Date 27 AUG 96
TAXONOMY
NAME - grouper, Nassau
OTHER COMMON NAMES - Nassau grouper, grouper, rockfish and hamlet
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - Chordata,
CLASS AND SUBCLASS - Osteichthyes,
ORDER AND SUBORDER - Perciformes,
FAMILY AND SUBFAMILY - Serranidae,
GENUS AND SUBGENUS - Epinephelus,
SPECIES AND SSP - striatus,
SCIENTIFIC NAME - Epinephelus striatus
AUTHORITY - Bloch, 1792
TAXONOMY REFERENCES - 200
Taxonomy - 1 (DRAFT) - Status
Species grouper, Nassau
Species Id M010412
Date 27 AUG 96
STATUS
Coded Status
Sport Fish
REFERENCES FOR STATUS - 200
COMMENTS ON STATUS -
Despite their economic importance, available information on the life history
of black and Nassau groupers is grossly inadequate for effective management
of the fishery. Few studies have been published on the biology of the
groupers and are mainly focused on tagging programs that describe movement
patterns.*200*
Status - 1 (DRAFT) - Distribution
Species grouper, Nassau
Species Id M010412
Date 27 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Marine RF.
Marine RB.
Estuarine AB3
REFERENCES FOR NWI - 200
COMMENTS ON HABITAT ASSOCIATIONS -
Like most species of groupers, the black, red and Nassau groupers are
secretive, occupying caves, ledges and crevices on reefs and shipwrecks.
The larger fish generally occupy the lower part of the depth range. The
Nassau grouper is generally found near high-relief coral reefs and rocky
bottoms from the shoreline to a depth of at least 90m. It is reported that
large fish occur at depths greater than about 50 m. In Bermuda, there is a
marked size segregation; fish less than 40 cm SL were on inshore banks and
larger ones were on offshore banks. *200*
Habitat Associations - 1 (DRAFT) - Food Habits
Species grouper, Nassau
Species Id M010412
Date 27 AUG 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
REFERENCES FOR TROPHIC LEVEL - 200
LIFESTAGE FOOD FOOD PART
General Crustaceans Not Specified
General Squid, Octopus Not Specified
General Fish Not Specified
Juvenile Plankton Not Applicable
REFERENCES FOR GENERAL FOOD - 200
REFERENCES FOR JUVENILE FOOD - 202
COMMENTS ON FOOD -
All the groupers are carnivorous, feeding mainly on fishes, larger
crustaceans, and occasionally on cephalopods.*202*
Nassau groupers may consume queen conchs after other predators have made
soft parts available. In Bahamian waters, however, Nassau groupers have
been observed forcefully pulling conchs out of their shells. Moray eels
have been reported in stomachs of Nassau groupers collected in the Virgin
Islands and Puerto Rico and Jamaica.*200*
COMMENTS ON ADULT FOOD -
Stomach contents of 150 Nassau groupers collected during daylight off the
Virgin Islands and Puerto Rico consisted of about 53% fish, 39% crustaceans,
5% cephalopods, 2% gastropods, and 2% pelecypods.*200*
COMMENTS ON JUVENILE FOOD -
Many studies report some change in proportion of various food items-- eg.,
consumption of more fish and less crustaceans with increasing age. There is
evidence that snappers and groupers eat other snappers and groupers. The
prey are usually rather young stages, but predation on adults does
occur.*202*
Crustaceans dominated the diet of smaller fish, whereas fish predominated in
the stomach contents of larger Nassau groupers over 300 mm SL.*200*
Food Habits - 1 (DRAFT) - Environment Associations
Species grouper, Nassau
Species Id M010412
Date 27 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 Substrate: Rocks
G
A Water Depth Preference: 50-100 ft.
G Biodegradable Organics: Wide range of tolerance to organic pollution
FJ Bottom Type [Aquatic]: Rooted aquatic vegetation
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 200
REFERENCES FOR RESTING ADULT ENVIRONMENTAL ASSOC_ - 200
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
The Nassau grouper is generally found near high-relief coral reefs and
rocky bottoms from the shoreline to a depth of at least 90 m. Large fish
occur at depths greater than about 50 m. In Bermuda, a marked size
segregation was noted: fish less than 40 cm SL were on inshore banks. The
species may be resistant to changing salinities. In the old New York
Aquarium, several Nassau groupers reportedly lived for several years in
water that occasionally became almost fresh and was rather polluted.*200*
Environment Associations - 1 (DRAFT) - Life History
Species grouper, Nassau
Species Id M010412
Date 27 AUG 96
LIFE HISTORY
Morphology:
This grouper can be distiguished from other species in the genus Epinephelus
by the third spine of the dorsal fin which is longer than the second, and in
having a slightly indented interspinous membrane. The caudal fin is
slightly emarginated. In Nassau groupers the pelvic fins are shorter than
the pectorals and are inserted below or behind the ventral end of the
pectoral fin base. The Nassau grouper can be distinguished from
Mycteroperca spp. by its less elongated body and eight soft anal fin rays.
Other serranid species have less robust bodies, soft dorsal and anal fin
bases that are not covered by scales or thick skin, and 10 or fewer dorsal
fin spines.
Coloration:
In this species the body ground color can be tawny to pinkish and red, with
five dark vertical bars; the third and fourth bars divide above the lateral
line and their adjacent branches join to form a w-shaped mark. The Nassau
and red groupers are somewhat similar in general appearance, but can be
distinguished because the Nassau grouper has a black saddle on top of the
caudal peduncle, distincitve black spots below and behind the eyes, and a
characteristic "tuning fork" shaped mark on the top of the head, all of
which are lacking in the red grouper.*200*
Sex reversal:
The Nassau grouper changes from female to male at a length between 300 and
800 mm, which presumably indicated that an individual fish can spend more
than one spawning season as a functional female. In the Caribbean, ripe
fish were collected between February and May, and sexually inactive ones
were collected in October and November. Nassau groupers form spawning
aggregations of as many as 100,000 fish off Bimini, Bahamas, for 1 week
during the full moon in January. Similar aggregations have been found in
other Carribean areas.*200*
Movement:
Nassau groupers have been reported to form enormous spawning aggregations
and undergo spawning migrations. Analyses of gonad samples indicates that
fish of both sexes are present and ripe during the aggregations.
Tagged Nassau groupers in the Florida Keys promptly returned to their
original reef, showing strong home-reef specificity. Tagged Nassau groupers
in the Virgin Islands moved at most about 820 m from the site of release.
From results of tagging studies, it was reported that the Nassau grouper
tends to become established in an area.*200*
REFERENCES FOR LIFE HISTORY- 200
Life History - 1 (DRAFT) - Management Practices
Species grouper, Nassau
Species Id M010412
Date 27 AUG 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Providing artificial nesting/spawning sites
Beneficial Regulating harvest - setting size limits
Existing Regulating commercial harvest gear types
REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 200
REFERENCES FOR EXISTING MANAGEMENT PRACTICES - 200
COMMENTS ON MANAGEMENT PRACTICES -
The minimum size for any species (including species such as scamp and gag)
is 18 inches total length. New gear restrictions prohibit use of longline
nets and stab nets (also called sink nets) off the Atlantic coast of
Florida.
Artificial reef programs designed to improve recreational fishing in the
ocean have become popular in recent years; most activity in United States
waters has been in Florida. Artificial reefs consisting of a wide variety
of materials, ranging from abandoned vessels to designed and prefabricated
structures and even junk (debris, large appliances, etc.), have been placed
on the coasts of Florida (greatest activity has been in Dade County). A
controversy exists as to the best depths for artificial reefs. Among the
recreational fishermen, there seems to be a consensus favoring water about
73 m deep, where diving and spearfishing are discouraged and reefs tend to
attract large fish. The long-term effect of artificial reef placement would
seem to be that recreational catches of groupers would improve, perhaps in
some proportion to the numbers and kinds of artificial reefs installed. It
is not known if artificial reefs increase fish populations or just
redistribute them.*200*
Size limits that maximize yield per recruit for gonochoristic (bisexual)
species would probably allow continued adequate reproduction of that species
regardless of fishing mortality if release-related mortality is low.
Protection of reproduction occurs because the size limit that maximizes
yield per recruit appears mathematically related to the downward inflection
of the von Bertalanffy growth curve. The inflection usually occurs at the
initial age of sexual maturity when the fish's energy is partially diverted
from somatic growth to reproduction. Thus, size limits that maximize yield
per recruit usually allow attainment of sexual maturity.*202*
Management Practices - 1 (DRAFT) - References
Species grouper, Nassau
Species Id M010412
Date 27 AUG 96
References
200 * Jory, Darryl, Iverson, Edwin. 1989. Species Profiles: Life
Histories and Environmental Requirements of Coastal Fishes and
Invertebrates (South Florida)--Black, Red and Nassau Groupers.
Fish and Wildlife Species Profiles 82(11.110) (ed.). Fish and
202 * Polovina, Jeffrey (Ed.) and Stephen Ralston (Ed.). 1987.
Tropical Snapper and Groupers: Biology and Fisheries Management.
Polovina, J. and Ralston, S. (ed.). Westview Press Boulder, CO
and London, England:659.
191 * South Atlantic Fishery Management Council. 1988. Amendment
Number 1 and Environmental Assessment and Regulatory Impact
Review To The Fishery Management Plan For The Snapper Grouper
Fishery of The South Atlantic Region. (ed.):46.
References - 1