Phototoxicity and fish predation: selective factors in color morphs ofHeterocope
Limnology and Oceanography
phototoxicity, fish, predation, color morph, heterocope
In the Toolik Lake region of arctic Alaska, Heterocope septentrionalis occurs in two distinct color morphs, dark red and pale green. The dark form tends to occur in shallow fishless ponds and the pale form in large, deep lakes with fish. Phototoxicity and fish predation experiments on the two morphs showed that the dark red form had better survivorship in bright sunlight and the pale green form was less susceptible to predation by visually feeding fish. The red color is caused by a keto-carotenoid pigment. In lakes where predation presents a threat than sunlight the keto-carotenoid pigment is complexed with a protein to produce green Heterocope.
Luecke, C., and W.J. O'Brien. 1981. Phototoxicity and fish predation: selective factors in color morphs of Heterocope. Limnol. Oceanogr. 26:454-460.