HERRING FAMILY (Clupeidac) 

 ALEWIFE 



Alosa pseudoharengus (Wilson) 



The alewife is the most numerous of fishes migrating up Maine's 

 coastal streams and rivers. The row of spiny scutes along the midline 

 of the belly is a distinguishing character and has been responsible for 

 the common name, "sawbelly." General range of the alewife is from 

 Nova Scotia and the Gulf of St. Lawrence to the Carolinas. Although 

 landlocked populations are abundant in the Great Lakes and New 

 York's Finger Lakes, alewives of Maine spend the larger portion of their 

 life history in the ocean. 



Spawning runs of adults begin the latter part of April and continue 

 on into June in more northern waters. As the end of the spawning run 

 approaches, ripe fish on their way upstream are passing spent fish return- 

 ing to the ocean, although some adults may stay in fresh water until 

 December. Average length of migrating adults is slightly less than one 

 foot in Maine with an average weight of one-half pound. Fish may 

 be 3, 4, 5, or 6 years old but the majority of the spawning run will be 

 4- and 5-year-olds. A fairly significant percentage return to spawn 

 again. Movement takes place largely during daylight hours. Most of 

 the runs are restricted to a few miles, but alewives reach the headwaters 

 of the Narraguagus and East Machias Rivers in their search for a fresh- 

 water pond. 



Females will deposit from 60,000 to 100,000 eggs depending on 

 the size fish. The eggs fall to the bottom where they attach to stones, 

 sticks, and any other objects that may be present. Neither eggs nor 

 young receive any parental care. Young alewives hatch in slightly less 

 than a week and spend their first, or at least part, of their first summer 

 in the freshwater pond growing rapidly on a diet of minute animals and 

 plants. Fishes utilizing this type of diet are referred to as plankton feed- 

 ers. Young alewives begin their seaward migrations about the middle 

 of the summer and the migration continues as late as November. Size 

 at migration varies with the length of time spent in fresh water after 

 hatching and may range from 1 Vi inches to 6 inches. Observations 

 made as part of the study of anadromous brook trout indicate that one 

 and two-year-old alewives frequent estuaries in large numbers apparently 

 as part of their feeding activities. 



There is a direct correlation between size of run and available 

 lake area. A properly managed alewife fishery must provide for some 

 escapement of adults to provide young stock. Fishways must be con- 

 structed where barriers exist to permit easy passage upstream for adults 

 and for downstream passage of young. Many runs of alewives have been 

 reestablished in Maine rivers during the past few years. 



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