78 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



on its way to salt water. Dates of arrival in Taunton River from 1871 

 to 1883 range from March 10th, in 1880, to April 5th, in 1883. June 

 5, 1906, Hazard's Quarry trap, two specimens; in 1906, arrived at 

 West Passage traps middle of March. Specimen taken in Warren 

 River, March 23, 1910. 



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

 Spawns in May and June. The eggs after being laid roll loosely on the 

 rocks, sand, or shelving flats, in non-tidal parts of the rivers. Eggs 

 are semi-buoyant, non-adhesive, one-eighth inch in diameter (3.24 

 mm.), and take eight days to hatch in water 60°F. Larva at hatching 

 are nine twenty-fourths inch (9.29 mm.) long. The shad returns to 

 salt water after spawning, as is shown by the capture of spent fish, 

 "Racers " on the opposite side of the net. 



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

 minute free-swimming Crustacea. 



Rate of Growth: Young, six to eight inches long, are taken in large 

 numbers in the fall at Long Island. (Bean, 1901.) Larva doubles its 

 length in ten days after hatching, measuring 3-5 inch (15.73 mm.) in 

 length; in 20 days it is 4-5 inches (19 mm.) long; in 40 days is 2 to 2\ 

 inches (56.95 mm.) long. On the seventieth day it reaches three or 

 four inches (75 to 100 mm.), in four months, five to seven inches (125 

 to 175 mm.). Shad, three to five inches long taken in rivers from Sep- 

 tember to February; in Potomac River specimens three inches long are 

 abundant in November, at which time shad five to seven inches long 

 are found in Maine rivers. Shad nine to thirteen and one-half inches 

 are frequent in Canadian waters in October, which must be the young 

 of the preceding year. (Prince, 1907.) 



References: 



1872: Yarrqw, Report U. S. Fish Com. I, 452. 



1882: Ryder, Bull. U. S. Fish Com. II, 179. 



1891: Worth, Bull. U. S. Fish Com. XI. 201. 



1897: Brice, Report U. S. Fish Com. XXIII, 133. 



1907: Prince, Further Contributions to Canadian Biology, 100. 



44. Opisthonema oglinum (LeSueur). Thread Herring. 



Geog. Dist.: West Indian fauna, straying to Cape Cod. Taken at in- 

 tervals at Buzzards Bay and Vineyard Sound, (Smith, 1S98). Abun- 

 dant in July and August at Gravesend Bay, (Bean.) 



Se.\son in R. I.: The type specimen described in 1817 by LeSueur was 

 taken at Newport. (Jour. Ac. Nat. Sci. Phila., I, 1817, 359.) In the 



