Spawning of Red Snapper (Lutjanus campechanus) in Response to Hormonal Induction or Environmental Control in a Hatchery Setting

Abstract

Red snapper (Lutjanus campechanus) is a popular marine sportfish and is a significant part of the commercial fisheries in the Gulf of Mexico. It can be reproduced under hatchery conditions by induced spawning of wild-caught adults or by conditioning wild-caught adults to spawn naturally under controlled conditions. Mature females (Gondosomatic Index ω 1) occur in the northern Gulf of Mexico from May to September. When such females were collected off the Alabama coast and induced to spawn with HCG, 56 ± 17.3% of the females ovulated. Fecundity (ovulated floating eggs) varies, for 60 spawns averaged 197,212 ± 173,349 eggs/kg female. Percent hatch averaged 42.1 ± 3.44%. Wild-caught adult red snapper can be held in confinement and natural spawning obtained when temperature and photoperiod are controlled. Adult snapper held in 13.2-m³ tanks (8–10 fish/tank), where photoperiod and temperatures were adjusted, spawned naturally 63 times over a 105-day period, with a mean egg production/tank of 4.2 million eggs. Mean fertilization rate, hatch rate, and survival at 36–40 hph were 90.5%, 83%, and 49%, respectively. Natural spawns produce better quality seed, but the occurrence of fertilized spawns is unpredictable. Hormone-induced spawns are easier to schedule but egg quality can be variable.

Keywords:

• red snapper
• reproduction
• fecundity
• spawning

ACKNOWLEDGMENTS

The activities were possible in large part due to the assistance of the staff of the Alabama Marine Resources of the Alabama Department of Conservation working at Claude Peteet Mariculture Research Station in Gulf Shores, Alabama, and the facilities they provided. We are very grateful for the support from the USDA Grant 2001-34421-10376 and Grant Award #NA86RG0039-4 project number R/SP-2 from the Mississippi-Alabama Sea Grant College Program.