Fig. 168.—Gofu, or Poison Fish, Synanceia verrucosa (Linnæus). Family Scorpænidæ. Specimen from Apia, Samoa, showing resemblance to coral masses, in the clefts of which it lives.
Sexual Coloration.—In many groups of fishes the sexes are differently colored. In some cases bright-red, blue, or black markings characterize the male, the female having similar marks, but less distinct, and the bright colors replaced by olive, brown, or gray. In a few cases, however, the female has marks of a totally different nature, and scarcely less bright than those of the male.
Fig. 169.—Lizard-skipper, Alticus saliens (Forster). A blenny which lies out of water on lava-rocks, leaping from one to another with great agility. From nature; specimen from Point Distress, Tutuila Island, Samoa. (About one-half size.)
Nuptial Coloration.—Nuptial colors are those which appear on the male in the breeding season only, the pigment afterwards vanishing, leaving the sexes essentially alike. Such colors are found on most of the minnows and dace (Cyprinidæ) of the rivers and to a less degree in some other fresh-water fishes, as the darters (Etheostominæ) and the trout. In the minnows of many species the male in spring has the skin charged with bright pigment, red, black, or bright silvery, for the most part, the black most often on the head, the red on the head and body, and the silvery on the tips of the fins. At the same time other markings are intensified, and in many species the head and sometimes the body and fins are covered with warty excrescences. These shades are most distinct on the most vigorous males, and disappear with the warty excrescences after the fertilization of the eggs.
Fig. 170.—Blue-breasted Darter, Etheostoma camurum (Cope), the most brilliantly colored of American river-fishes. Cumberland Gap, Tennessee.
Nuptial colors do not often appear among marine fishes, and in but few families are the sexes distinguishable by differences in coloration.