TROPHIC COMPARISON AMONG TRIGLIDAE (PISCES, SCORPAENIFORMES) OFF BAJA-CALIFORNIA-SUR, MEXICO

Composition, intensity, diversity, ontogenetic and seasonal changes of feeding of Prionotus stephanophrys, Bellator gymnostethus and P. albi rostris were studied in the Pacific coast of Baja California Sur, Mexi co. A total of 547 individuals of the three species were sampled betwe en 1988 and 1990. The euphausiid Nyctiphanes simplex was the main prey of B. gymnostethus, which caught it during the day, and of P. stephan ophrys, which ate it at night and twilight; larger individuals of P. s tephanophrys shifted to Pleuroncodes planipes, a change that coincided with the fish' shift from the pelagic to the benthic environment. Fee ding intensity of this searobin was higher in summer, after reproducti on. P. albirostris fed throughout the day; its diet, more diverse and equitable, was based on penaeids, pasiphaeids, and mysids. Differences in spatial distribution, diet and time of feeding suggested efficient habitat partitioning among these fishes.