Red snapper (Lutjanus campechanus) associated with a small artificial structure in the Mississippi sound, a northern Gulf of Mexico estuary

During September 1994 - 1997, opportunistic sampling of red snapper (Lutjanus campechanus) at a small, artificial structure in the Mssissippi Sound estuary provided information on age, reproductive biology, diet and behavior of juvenile and adult red snapper from inshore habitat. The study represents the first detailed account of adult red snapper from a northern Gulf estuary. Red snapper (n = 302) collected from the study site ranged in size from 229 - 714 mm TL; 172 were retained for laboratory examination, and 130 were tagged and released. Age estimates for some specimens (n = 36; 326 - 713 min TL) ranged from 2 - 5 years. Histological assessment of gonads from a small sample of fish (n = 13) collected primarily during late summer and fall (near the end of the spawning season) revealed sexually mature males (n = 5; 390 - 520 mm TL) and females with regressed ovaries (n = 5; 326 - 662 nun TL) or immature ovaries (n = 2; 326 and 330 mm TL). However, ovaries from a single female collected during July (during the peak of the spawning season) contained oocytes in the final oocyte maturation (FOM) stage, an indication of imminent spawning. This finding was of great interest since red snapper are reported to spawn only in offshore waters. Snapper diet consisted of fish, crustaceans and cephalopods. Anchovies (Anchoa hepsetus and A. sp.) and hardhead catfish (Ariusfelis), were the dominant prey in the diet and occurred in 54 % of stomachs. Gulf crab (Callinectes similis), other portunid crabs, and penaeid shrimps were the primary crustaceans in the diet. Tag-recaptures (n = 32) were from the site of tag-release only and extended from 1 - 373 days-at-large. Recaptures documented growth for fish, primarily juveniles and young adults, at the study site and suggested site fidelity and overwintering for some fish. Aspects of the perennial occurrence of adult red snapper in the Mississippi Sound estuary are discussed.