54 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



39. Pomolobus aestivalis (Mitchill). Glut Herring; Blackback. (Plate X.) 

 Geog. Dist.: Coast waters United States north to Maine. 

 Migrations: Similar to the alewife (P. pseudoharengus) , except that it 



appears later and remains in fresh water for a shorter time. 



Season in R. I.: It appears from two weeks to a month later than the ale- 

 wnfe. 



Reproduction: Similar to the alewife, but about two weeks later; the 

 spawning grounds are probably confined to brackish water in ponds, and 

 in large streams not far above tide water. 



Food: Free-swimming Crustacea. 



40. Alosasapidissima (Wilson). Shad. (Plate XI.) 



Geog. Dist.: From Alabama along the whole Atlantic coast. Introduced 

 by the U. S. Fish Commission into rivers of Pacifie coast. 



Migrations: Probably lives in deep water in winter or near Gulf Stream, 

 coming into shore waters when the temperature reaches 60°F., running up 

 rivers to spawn. When this process is completed they probably return to 

 salt water. The young, when hatched, remain in rivers till autumn, then 

 move into salt water. 



Season in R. I. : Arrives last of March and runs for about 6 weeks. A large 

 specimen taken August 3, 1905, at Rumstick Point. Specimen 3 inches 

 long, taken October 29, 1905, at Dutch Island Harbor; this was probably 

 hatched from spaAvn of the previous spring, and was then on its way to 

 salt water. Dates of arrival in Taunton River from 1871 to 1883 range 

 from March 10 in 1880 to April 5 in 1883. 



Reproduction: Spawning takes place in fresh water in April and May. 



Food: Like the other members of this family, its chief food supply consists 

 of minute free-swimming Crustacea. 



Size: Maximum, 2^ feet. It reaches its full size in four years. 



41. Opisthonema Oglinum (LeSueur). Thread Herring. 



Geog. Dist.: West Indian fauna, straying north to Cape Cod. The type 

 specimen described in 1817 by LeSueur was taken at Newport. (Jour. 

 Ac. Nat. Sci. Phila., I, 1817, 359.) In the U. S. National Museum is a 

 specimen taken at Newport by the U. S. Fish Commission. (Bull. U. S. 

 Nat. Mus., 1879, 60.) A few have been taken very rarely since. 



