Influence of temperature on the fatty acid pattern of mosquitofish (Gambusia affinis) and guppies (Lebistes reticulatus)

Adult male mosquitofish were adapted to 14–15C and 26–27C water temperature over a 14‐day period and the fatty acids from their total lipids analyzed by gasliquid chromatography. Newly born guppies were raised at the same temperature for eight weeks and analyzed in the same way. Some fish in the warm water group were subjected to a sudden drop in temperature and the changes of the fatty acids studied after two and eight days, and after two and four weeks. In all fish the tendency is toward higher unsaturation at lower temperature, but the acids involved in the change differ with the species of fish. A distinct difference is also obvious when guppies are raised at, or when they are adapted to the low temperature. The diet, too, influences the kind and amount of fatty acid synthesis and deposition.