Diurnal-Nocturnal Activity of Some Inshore Fishes in the Gulf of California

Abstract

the southern Gulf of California. Certain patterns of behavior within and between species were consistently observed, and permit a number of tentative generalizations regarding feeding habits, schooling, and other activity in relation to time of day. Species with predominently diurnal foraging habits include: Mycteroperca rosacea (Streets), Epinephelus labriformis (Jenyns), Chromis atrilobata (Gill), Eupomacentrus rectifraenum (Gill), Abudefduf troschelii (Gill), Bodianus diplotaenia (Gill), Thalassoma lucasanum (Gill), Scarus californiensis (Pellegrin), Heniochus nigrirostris (Gill), Prionurus punctatus Gill, Runula azalea Jordan and Bollman, Balistes verres Gilbert and Starks, and Balistes polylepis Steindachner. Species obtaining most of their food at night include: Holocentrus suborbitalis (Gill), Myripristis occidentalis Gill, Rypticus bicolor (Valenciennes), Lutjanus argentiventris (Peters), Apogon retrosella (Gill), Microlepidotus inornatus Gill, Anisotremus interruptus Gill, Haemulon sexfasciatum Gill, Selar crumenophthalmus (Bloch), and Pareques viola (Gilbert). A number of other species are introduced as their activity relates to the discussion. The nocturnal species are predators, while the herbivorous and omnivorous fishes show predominantly diurnal feeding habits. Those species schooling in dense, relatively inactive schools inshore during the day are nocturnal feeders and the school functions in defense against diurnal predators. Members of these schools disperse to feed at night, often after moving a considerable distance offshore.