160 



BULLETIN OF THE BUREAU OF FISHERIES 



tail fin) that it is not apt to be mistaken. It is a stocky little fish more than half 

 as thick as deep, but flat-sided, with high arched back, small flat-topped head, small 

 terminal mouth hardly gaping back to the forward edge of the eye, and with the 

 thick caudal peduncle characteristic of its family. Its tail is square (rounded in 

 the mummichogs), and the fact that almost the whole dorsal fin is in front of the 

 anal instead of over it affords another point of difference. The pectorals are large, 

 reaching back past the base of the ventrals, which by contrast are very small. Both 

 body and head are covered with large rounded scales, largest on top of the head and 

 on the cheeks. Young fish are proportionally more slender than old ones. In this 

 species, as in the mummichogs, the dorsal, ventral, and anal fins are higher in the 

 males than in the females. The male, too, is deeper bodied and averages larger. 



Color. — Out of breeding season both males and females are olive above (males 

 rather darker and greener than females) with pale yellow or yellowish- white belly, 



h 



^SfBSe 



Fig. 67. — Sheepsnead minnow ( Cyprinodon varugalus) 



dusky dorsal, and pale orange pectoral, ventral, and anal fins. The young of both 

 sexes are irregularly barred with black transverse stripes, which persist through 

 life in the female but become obscured in adult males. Females, furthermore, have 

 a black spot on the rear corner of the dorsal fin, which is wanting in males, while 

 the caudal fin of the latter sex is marked by two black cross stripes, one at the 

 base and the other at its margin. In breeding season the male assumes a very 

 brilliant coat, his upper parts turning to steel blue in front of the dorsal fin with a 

 greenish luster behind it, while his belly brightens to a deep salmon, his ventrals 

 and anal change to dusky margined with orange, and his dorsal shows an orange 

 margin in front. 



Size . — The largest specimens are about 3 inches long. 



General range. — Atlantic coast of the United States, Cape Cod to Mexico, in 

 brackish as well as in salt water. 



