532 EHRLICH, McGOWEN, AND MUSZYNSKI 



direct the fish to areas of reduced predation. Norris (1963) showed 

 that preference of warm water by young opal eye (Girella nigricans) 

 directs them from offshore into intertidal areas. Third, food levels 

 may be higher inshore or in bays and harbors. In King Harbor many 

 atherine larvae are found in the back basins that are warmest and 

 contain the highest concentration of food organisms (McGowen, 

 unpublished data). Beitinger (1977) suggested that seeking the 

 warmest water available, below temperatures that are detrimental, 

 may be beneficial to fishes. 



The thermal behavioral responses of topsmelt suggest that they 

 may be attracted to warmed water, such as power-plant effluents, as 

 has been observed by Stephens (1977). This does not imply, 

 however, that these conditions are necessarily beneficial to them. 

 Before any conclusion can be reached, such factors as the fish's 

 physiological thermal optimum, susceptibility to predation and 

 disease, and ability to compete must also be considered. 



REFERENCES 



Beitinger, T. L., 1976, Behavioral Thermoregulation by Bluegill Exposed to Vari- 

 ous Rates of Temperature Change, in Thermal Ecology II, ERDA Symposium 

 Series, Augusta, Ga., Apr. 2—5, 1975, G. W. Esch and R. W. McFarlane 

 (Eds.), pp. 176-179, CONF-750425, NTIS. 



, 1977, Thermopreference Behavior of Bluegill (Lepomis macrochirus) 



Subjected to Restrictions in Available Temperature Range, Copeia, 1977: 

 536-541. 



Blaxter, J. H. S., 1969, Development: Eggs and Larvae, in Fish Physiology, W. S. 

 Hoar and D.J. Randall (Eds.), Vol. 3, pp. 177-252, Academic Press, Inc., 

 New York. 



, 1970, Light-Fishes, in Marine Ecology, O. Kinne (Ed.), Vol. I, pp. 213-285, 



John Wiley & Sons, Inc., New York. 



Brett, J. R., 1956, Some Principles in the Thermal Requirements of Fishes, Q. 

 Rev. Biol., 31: 75-87. 



, 1971, Energetic Responses of Salmon to Temperature. A Study of Some 



Thermal Relations in the Physiology and Freshwater Ecology of Sockeye 

 Salmon (Oncorhynchus nerka). Am. Zool., 11: 99-113. 



Doudoroff, P., 1938, Reactions of Marine Fishes to Temperature Gradients, 

 Biol. Bull., 75: 494-509. 



, 1945, The Resistance and Acclimation of Marine Fishes to Temperature 



Changes. II. Experiments with Fundulus and Aiherinops, Biol. Bull., 88(2): 

 194-206. 



Ehrlich, K. F., 1977, Laboratory Thermal Effects Investigations on Marine 

 Fishes, in Effects of Thermal Effluent from Southern California Edison's 

 Redondo Beach Steam Generating Plant on the Warm Temperate Fish Fauna 

 of King Harbor Marina, Annual Report for Phase II, Mar. 1, 1975, to Feb. 29, 

 1976, Southern California Edison, Redondo Beach. 



, and D. A. Farris, 1971, Some Influences of Temperature on the 

 Development of the Grunion Leuresthes tenuis (Ayres), Calif. Fish Game, 

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