MANUAL OF FISH-CULTURE. 225 



sheepsliead swim in schools, and seem to prefer sandy beaches, along 

 which they resort at a depth of 6 or 8 feet. 



The sheepsliead egg is very small, transparent, and of less specific 

 gravity than sea Avater. The diameter is ;j\, of an inch, and the number 

 in a fluid ounce is about 50,000, or 1,(300,000 in a quart. 



The eggs are satisfactorily incubated in the tidal cod-jar, about 

 300,000 eggs being placed in each jar. The development is very rapid, 

 and in the warm water of the Gulf (76° or 77° F.) the eggs hatch in 40 

 hours. The newly hatched fry are very small, but active and strong, 

 and Avithstand considerable rough handling. They are planted when 

 72 to 80 hours old. 



It is probably not practicable to carry on extensive sheepshead 

 hatching north of Florida, although small quantities of eggs could 

 doubtless be taken in North Carolina and Virginia. 



THE SEA HERRING. 



The sea herring {Glupea harengus) may be distinguished from other 

 clupeoid fishes found in United States waters by the following char- 

 acters: Body elongate and laterally comi^ressed, the- depth contained 

 4i times in length; mouth at end of snout; lower jaw projecting, 

 extending to beneath the middle of eye ; roof of mouth with an ovate 

 patch of small teeth; gillrakers long and slender, about 40 below 

 the angle in adults, fewer in young; dorsal fin with 18 rays, inserted 

 slightly behind middle of body; ventral fins beginning beneath middle 

 of dorsal; anal fin with 17 rays; median line of belly with 28 weak 

 spines or scutes in front of ventral fins and 13 behind fins; scales thin, 

 easily detached, j^osterior edges rounded, 57 in lateral series; color 

 bluish or bluish-green above, light-silvery below. 



The sea herring exists in great abundance on both shores of the 

 Atlantic Ocean north of the latitude of about 37° north. On the coast 

 of North America it is not regularly abundant south of Cape Cod, but 

 it is occasionally found as far south as Chesapeake Bay. In number of 

 individuals this species is probably exceeded by no other fish. On the 

 Pacific Coast a similar and almost equally abundant species {Clupea 

 pidlasii) is found from Alaska to Mexico. 



There are no well-defined movements of the herring on the west 

 shore of the Atlantic, if those induced by the spawning instinct are 

 excepted. There was formerly a distinct shoreward migration, during 

 the winter months, in the Bay of Fundy, but this run has not occurred 

 for a number of years. In many places the herring, especially the 

 smaller individuals, appear to be resident in the shore waters. The 

 maximum length of this fish is about 17 inches, and tlie usiual length of 

 spawning fish on the United States coast is from 11 to 14 inches. 



The herring subsists on minute invertebrates, chief among which are 

 copepods, larval worms, and larval mollusks. In turn it is consumed 

 in enormous quantities by cod, haddock, sharks, and many other fishes. 



F. C. K. 1897 15 



