BIOLOGY AND NATURAL HISTORY 121 



sexes reach maturity. Most males are sexually mature at the end of two 

 years growth, while females require at least four years, at the end of which 

 time only about 25 per cent are mature. Merriman estimated that at the end 

 of the fifth year of life, 75 per cent of the females are sexually mature, the 

 remaining 25 per cent requiring six or seven years. The majority of the 

 spawning males at Weldon are two-year-olds, with smaller numbers of three- 

 and four-year olds; females, however, are all over four years old, accounting 

 for their larger size. 



The number of eggs produced per female varies greatly with the size of 

 the fish. Worth (1903) reports egg counts from 11,000 to 1,215,000 but does 

 not include data on size or weight. Merriman found a 4^ -pound female con- 

 taining 265,000 eggs. Bigelow and Welsh (1925) report a 12-pound fish 

 which produced 1,280,000 and estimate that a 75-pound fish would produce 

 10,000,000 eggs. The eggs are semi-buoyant and are therefore carried down- 

 stream during the development period. The time required for hatching, 

 dependent on water temperature, is from 30 to 74 hours. Considering the 

 current of the Roanoke River, Merriman believes that many of the eggs 

 produced in the vicinity of Weldon, North Carolina, may reach Albemarle 

 Sound before hatching. 



The young fish apparently remain in fresh or brackish water for two 

 summers, for young-of-the-year and yearly fish are rarely taken in outer 

 coastal waters. Young bass feed on small invertebrates such as fresh-water 

 shrimp, insects, and worms (Townes, 1937; Hildebrand and Schroeder, 

 1928; and Merriman, 1941). The older and larger bass are known to feed 

 largely on other species of fish, such as menhaden, alewives, shad, silver-sides 

 (Menidia), killifish {Fundulus), and shiners {Notropis). Other species of 

 fish and Crustacea are also taken in lesser quantities. 



The rate of growth of the striped bass has been studied by Merriman. 

 Measurements were made of fish ranging from one month to nine years of 

 age. There is some evidence of varying growth rates in different localities 

 along the coast. In 1937, for example, the two- and three-year-old fish from 

 Massachusetts were larger than the Connecticut bass of the same age. The 

 average lengths (from tip of nose to fork of tail) of striped bass at successive 

 years of age are given by Merriman as follows : 



