166 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Figure 78. — Sheepshead minnow (Cyprinodon variegalus), Maryland. From Jordan and Evermann. Drawing by 



A. H. Baldwin. 



are in the mummichogs. The male is deeper 

 bodied and the average size is larger than that 

 of the female. 



Color. — Out of breeding season both males and 

 females are olive above (males rather darker and 

 greener than females) with pale yellow or yellow- 

 ish-white belly, dusky dorsal fin, 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 lacking in 

 males, while the caudal fin of the male is marked 

 by two black cross stripes, one at the base and 

 the other at the margin. In breeding season 

 the male assumes a brilliant coat, his upper 

 parts turning to steel blue in front of the dorsal 

 fin with a greenish luster behind it, whde his 

 beUy brightens to a deep salmon, his ventrals 

 and anal change to dusky margined with orange, 

 and the front edge of his dorsal turns orange. 



Size. — The largest specimens are about 3 

 inches long. 



Habits. — The sheepshead minnow (like the com- 

 mon mummichog) is confined to the shallow waters 

 of inlets, harbors, and the heads of bays, and salt 

 marshes, often in brackish water. Its diet is 



partly vegetable, partly animal. It is very pug- 

 nacious, often killing fishes larger than itself, 

 making repeated attacks with its sharp teeth and 

 finally devouring its victim. It6 breeding habits 

 recall those of the mummichog (p. 163), the males 

 fighting fiercely among themselves and clasping 

 the females just forward of the tail with dorsal 

 and anal fin, while the eggs and milt are extruded. 

 Spawning takes place in shallow water from April 

 to September, the eggs maturing a few at a time, 

 so that any given female spawns at intervals 

 throughout the season. The eggs sink and stick 

 together in clumps by numerous threads. They 

 are 1.2 to 1.4 mm. in diameter, with one large oil 

 globule and many minute ones. Incubation oc- 

 cupies 5 or G days, and even at hatching the larvae 

 (4 mm. long) show alternate light and dark cross- 

 bands. At a length of 9 mm. all the fins are 

 formed, and at 12 mm. the fry show most of the 

 characters of its parents. 2 



General range. — Atlantic coast of the United 

 States, Cape Cod to Mexico, in brackish as well 

 as in salt water. 



Occurrence in the Gulf of Maine.- — This fish, hke 

 many others, finds its northern limit at Cape Cod 



i An account of courtship and spawning Is given by Newman (Biol. Bull., 

 vol. 12, No. 6, 1907, p. 336) and of development by Kuntz (Bull., U. S. Bur. 

 Of Fish., vol. 34, (1914) 1916, p. 409). 



