Nassau Grouper (Epinephelus striatus)

TAXONOMY AND NAMING

Class : Actinopterygii
Order : Perciformes
Family : Serranidae
Genus/species : Epinephelus
Common names :
English : Nassau Grouper
Spanish : Mero estriado
French : Mérou de Nassau

ANATOMY AND MORPHOLOGY

The Nassau grouper is a medium to large fish, growing to over a meter in length and up to 25 kg in weight. It has a thick body and large mouth, which it uses to "inhale" prey. Its color varies depending on an individual fish’s circumstances and environment. In shallow water (down to 60 ft), the grouper is a tawny color, but specimens living in deeper waters are pinkish or red, or sometimes orange-red in color. Superimposed on this base color are a number of lighter stripes, darker spots, bars, and patterns, including black spots below and behind the eye, and a forked stripe on the top of the head.

DISTRIBUTION AND LIFE HISTORY

The Nassau grouper lives in the sea near reefs ; it is one of the largest fish to be found around coral reefs. It can be found from the shoreline to nearly 100-m-deep water. It lives in the western Atlantic Ocean and around the Caribbean Sea, from Bermuda, Florida, and the Bahamas in the north to the eastern coast of Venezuela, but it is only found in a few places in the Gulf of Mexico, most notably along the coast of Belize.

It is a solitary fish, feeding in the daytime, mainly on other fish and small crustaceans such as crabs and small lobsters. It spawns in December and January, always around the time of the full moon, and always in the same locations. By the light of the full moon, huge numbers of the grouper cluster together to mate in mass spawning.

THREATS

The threats to the grouper include overfishing, fishing during the breeding period, habitat loss, pollution, invasive species, and catching undersized grouper. A productivity-susceptibility analysis shows the five species of the family Pristidae are the most threatened elasmobranchs in the world, as a result of their high exposure to coastal shallow-water fisheries and their sow life history and large body size. The Nassau grouper is fished both commercially and for sport ; it is less shy than other groupers, and is readily approached by scuba divers. Furthermore, its historic spawning areas are easily targeted for fishing, which tends to remove the reproductively active members of the group.

ABUNDANCE AND CONSERVATION STATUS

Numbers of Nassau Groupers have been sharply reduced by overfishing in recent years, and it is a slow breeder. The current population is estimated to be more than 10,000 mature individuals, but is thought to be decreasing. The species is therefore highly vulnerable to overexploitation, and is recognised as critically endangered on the IUCN Red List.

PROTECTION STATUS

Many conservation methods have been put in place to help the grouper, including closed seasons, when fishing is not allowed.

CITES  : no

Protocol SPAW  : yes_Annex III

CMS  : yes_Annex I and II

International convention and protection for the Nassau Grouper

Bibliography

Compagno et Last 1999
Dulvy et al. (2014)