Biology of the Red Snapper, Lutjanus aya Bloch, of the Northwestern Gulf of Mexico.

Adult and juvenile red snappers were collected at irregular intervals in the northwesten Gulf of Mexico from February 1964 through March 1965. Stomach analyses indicated that red snappers were polyphagous. Adult red snappers were primarily piscivorous, although in certain seasons, they fed heavily on tunicates. Juvenile red snappers fed primarily on crustaceans, but periodically took fish. Age-growth studies conducted via scale readings indicated that red snappers have a more rapid growth rate than other lutjanids. It was found that Lutjanus aya attained a standard length of 200-220 mm their first year, and grew 80 to 90 mm each successive year up to spawning class III. The spawning season for red snappers off the Texas coast was found to be June to Mid-September, with the peak occurring in August. Adult red snappers seemed to prefer areas of hard limestone bottoms or irregular bottom formations, although commercial catch data and food studies indicated that they were not confined to these areas. Juveniles were collected only in waters over sandy and muddy bottoms, indicating that they do not show a complete preference for limestone bottoms or irregular bottom formations.