Ecological Significance of Temperature Tolerance and Preference of Some Inshore California Fishes

Abstract

Abstract Dwarf perch Micrometrus minimus, shiner perch Cymatogaster aggregata, blacksmith Chromis punctipinnis, black perch Embiotoca jacksoni, rainbow seaperch Hypsurus caryi, and calico rockfish Sebastes dalli were collected in a vertical thermal gradient at the breakwater of King Harbor, Redondo Beach, California. Fish were acclimated at the field temperature. Acute preferred temperatures and avoidance temperatures determined in the laboratory were compared with temperatures in the field gradient at which the species were collected or observed by divers. Dwarf and black perch preferred temperatures significantly lower than their field temperatures. Preferred temperatures of the other four species were consistent with temperatures at their positions in the harbor. Although the field distributions of the six species are thermally differentiated, those of two species appear to be determined by factors other than temperature.