Nassau grouper
| Nassau grouper | ||||||||||||
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Nassau grouper ( Epinephelus striatus ) |
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| Scientific name | ||||||||||||
| Epinephelus striatus | ||||||||||||
| ( Bloch , 1792) |
The Nassau grouper ( Epinephelus striatus ) is also known to divers under its English name Nassau Grouper .
features
Nassau groupers have a typical perch shape with a front, hard-nosed and a rear, soft-nosed dorsal fin. The hard-rayed part is indented, the third and fourth fin rays are the longest. The base of the dorsal fin section with soft rays and the anal fin are covered with small, large-area overlapping scales and with thick skin. The big mouth gives the Nassau groupers a "grim" appearance. They usually show a vertical pattern of light and dark stripes with a gray or brown base color. The third and fourth vertical stripes are divided above the sideline and are W-shaped. The stripes on the head form a tuning fork- like shape. A black saddle point on the base of the tail is typical of the species. Specimens from deeper water regions show a reddish sheen. Nassau groupers can change their color from whitish to dark brown in a matter of minutes. They become 80 centimeters long. Young fish have a rounded tail fin, in adult fish it ends straight.
- Fin formula : dorsal XI – XII / 16–18, anal III / 8.
distribution
The fish live in the tropical West Atlantic , in the Caribbean , in the Gulf of Mexico , on the Florida coast , near the Bahamas and Bermuda , south to the coast of Brazil on rocky and coral reefs down to a depth of 40 meters. Due to commercial fishing and harpoon hunting, they have become rare in many regions of their range.
Reproduction
Like all saw bass, Nassau groupers undergo sex reassignment surgery during their lifetime. They are females first and switch to the male sex around the age of five. Therefore the males are always bigger. The time of reproduction is determined by the moon. New moon nights are the trigger in the Bahamas, full moon nights on the coast of Belize and the Virgin Islands . Then the solitary animals gather in huge groups of 30,000 to 100,000 animals and spawn together. The eggs are one millimeter in diameter. After just one day, the larvae hatch and live in the plankton for 30 to 40 days until they transform to reef-bound life after a metamorphosis .
literature
- Hans A. Baensch / Robert A. Patzner: Mergus Sea Water Atlas Volume 7 Perciformes (perch-like) , Mergus-Verlag, Melle, 1998, ISBN 3-88244-107-0
Web links
- Nassau grouper on Fishbase.org (English)
- Epinephelus striatus in the endangered Red List species the IUCN 2006. Posted by: Cornish & Eklund, 2003. Retrieved on 6 May, 2006.