586 NATUEAL HISTOEY OF AQTJx\TIO ANIMALS. 



Food. — As in the case of the Shad, very little is known concerning the food of the river 

 Alewives in their salt-water habitats. It is, however, supposed that they, like other similar 

 species, exist largely upon swimming crustaceans. When in the rivers they do not feed to any 

 considerable extent, although they have been known in many instances to take the flj'. 



Ebproduction. — The eggs of the Alewife are adhesive, like those of the sea Herring, though 

 to a much less degree. The number of eggs varies from sixty thousand to one hundred thousand, 

 in accordance with the size of the individual. They are deposited upon the bottom m shoal water, 

 or on whatever object they may come in contact with. The time for spawning, after the flsh have 

 entered the river, depends, as in the case of the Shad, entirely on the temperature of the water. 

 The spawning of the "Glut" Herring takes place under ordinary conditions at a temperature of 

 70° to 75° F.; that of the "Branch" Herring, when the water is as low as 55° to 60° F. The 

 period of development varies directly with the temperature. 



The season of incubation with the "Glut" Herriug is about the same as with the Shad — that 

 is, about three or four days. With the " Branch" Herriug the spawning takes place when the water 

 is colder, for which reason the period of incubation is doubtless longer. The young Alewife before 

 winter attains a length of two to three inches, and the period of growth continues, probably, as in 

 the Shad, for three or four years. 



"There seems to be," remarks Professor Baird,' "a difference of opinion as to the age at which 

 Alewives first return from the sea, some fixing ifc at two and others at three or more years. Captain 

 Treat, of Eastport, however, many years ago transported several hundred pairs of breeding fish 

 to a small sheet of water, known as Keene's Pond, situated some five or six miles from Eobinston, 

 Maine, and having its outlet into the Calais Eiver just below Eed Beach. The level of the lake is 

 several hundred feet above that of the river, and the outlet is very precipitous, consisting of 

 several falls entirely impassable to fish from below. ISo Alewives had ever been known in this 

 pond at the time of their introduction by Captain Treat. The young flsh were seen i ; the pond in 

 the course of the summer in myriads, all of them disappearing, however, after a heavy rain in the 

 autumn, which swelled the waters to produce ii suflcient discharge. Due examination was made 

 for successive years, but not until the expiration of the fourth were they seen, when the outlet was 

 observed to be almost choked up by a solid mass of Alewives, struggling to make their way back 

 again to the place of their birth." 



During past years the Alewife has frequently been artificially introduced into new waters or 

 over dams by the transportation of flsh of considerable size. This is constantly done on Cape Cod 

 in the restocking of the herring streams which have been exhausted, and was successfully accom- 

 plished by General N. L. Lincoln, in Maine, as long ago as 1750. Colonel Lyman, in his report 

 for 1870,^ describes the experiment by Mr. E. S. Haddoway in restocking Eel Liver, Town Brook, 

 Plymouth, in 1865. The crop sown by him in that year came up in 1869 in the shape of a good 

 run of flsh, chiefly males full grown. 



Herring eggs have frequently been artiflcially impregnated by men engaged in shad culture. 

 The young flsh artiflcially hatched have in some instances been transported, In 1882 two million 

 were sent to Texas by the United States Fish Commission and deposited in the Colorado Eiver. 

 Artiflcial hatching would seem less necessary in the case of the Alewife than in that of the Shad, 

 since with the former, owing to its peculiar spawning habits, the eggs stand a better chance of 

 hatching out, and very slight protection of the flsh during spawning season will be sufficient to 

 keep up the supply. The present law of the District of Columbia, by which pound-nets are kept 



lEoport, Uuitod States Fish Commission, part ii, 1874, p. Ixi. =Pago 7. 



