INTERNAL PARASITES OF THE SEBAGO SALMON. 



"73 



Occurrence of Parasites in Quinnat Salmon from Sacramento River — Continued. 



According to size of fish. 



It will be noted that the percentage of infestation increases rapidly with the 

 size and age of the fish, but this would naturally be associated with the more 

 extensive feeding of the older and larger fish, whether in fresh or salt water. In 

 the absence of comparative data for salt water forms to contrast with these of 

 summer residents in fresh water, it is not allowable to attribute this condition 

 to the delayed migration of these fish, as Rutter does. From brackish-water 

 stations 20 young salmon were examined and parasites found in 3 only. This 

 number is too small to be available for comparison with those fresh-water forms 

 noted above. Unfortunately no further data are available concerning the 

 varieties of parasites found either in the adult or in the young specimens. It is 

 probable that the adult parasites are the same as certain forms to be discussed 

 later from the Alaska salmon. 



OBSERVATIONS ON THE SEBAGO SALMON. 

 SPECIFIC RELATIONSHIPS 



The Sebago salmon is regarded by some as merely a landlocked variety of 

 the Atlantic salmon, Sahno salar, found both in European streams and in the 

 rivers of Maine and northward. By others it is viewed as a separate species, 

 Salmo sebago, but in any event closely related to the former. In their extensive 

 catalogue of North American fishes, Jordan and Evermann (1896) include all 

 these forms in the single species Salmo salar Linnaeus, speaking of its range as 

 follows : 



North Atlantic, ascending all suitable rivers in northern Europe and the region 

 north of Cape Cod to Hudson Bay; formerly abundant in the Hudson and occasional in 

 the Delaware, its northern limit in the Churchill, Albany, and Moose rivers, flowing into 

 Hudson Bay; sometimes perfectly landlocked in lakes in Maine and northward, where 

 its habits and coloration (but no tangible specific characters) change somewhat, when 

 it becomes (in America) vars. sebago and ouananiche. Similar landlocked varieties 

 occur in Europe. 



Of the Lake Sebago form which I had the opportunity of studying and 

 which these authors regard as a subspecies, Salmo salar sebago (Girard), they 

 write as follows : 



Smaller in size, rather more plump in form, and nonmigratory ; not otherwise evi- 

 dently different. Sebago Pond and northward; introduced into lakes in various parts 

 of the country; seldom entering streams; reaches a weight of 25 pounds. 



