FAMILY SALMONIDAE 111 



eastern Minnesota. Parker in 1857 cites the abundance of speckled 

 trout in the vicinity of Winona as an inducement to settlers. According 

 to a letter from Dr. C. L. Hubbs, brook trout are native in northeastern 

 Iowa . 



Brook trout are cold-water fish, thriving best in clear, cold, spring- 

 water streams and brooks in which the mean temperature rarely ex- 

 ceeds 50° F. Their food consists largely of insects, worms, and Crustacea. 

 There are certain lakes in the northern part of the state where the 

 species is virtually landlocked, and here they grow much larger than 

 they usually do in streams, as they do also around Isle Royale in Lake 

 Superior. Although they reach a length of 18 to 24 inches, it is doubtful 

 whether most of the brook trout taken in a majority of the streams in 

 the state much exceed 8 to 10 inches in length. One of the largest 

 specimens reported, taken in Nipigon River in Ontario by Dr. J. W. 

 Cook, weighed 14 1/2 pounds and measured 31 1/2 inches. 



Brook trout spawn in the fall, beginning early in September in some 

 of the North Shore streams and continuing to the later part of Novem- 

 ber. At spawning time the fish move far up the smallest creeks, selecting 

 gravel bottoms in shallow water for their spawning beds. There the 

 eggs lie without hatching until the water begins to grow warmer the 

 following spring (Jordan and Evermann, 1905) . 



The charge is often made that minnows and suckers destroy large 

 numbers of trout eggs on their natural spawning beds, but the writers 

 wish to take exception to this charge, claiming not that certain fishes 

 do not destroy the eggs but that there is an entirely different side to 

 the whole question. Years ago, by a systematic examination of many 

 natural spawning beds in the mountains of western North Carolina and 

 the Alleghanian region in West Virginia, in streams long famous for 

 their magnificent brook trout fishing, it was proved beyond question 

 that the actual damage done by most fishes is very small indeed. The 

 natural spawning beds are in swift water, usually in midstream, and 

 seldom over 2 feet deep, and therefore are more or less directly exposed 

 to the rays of the sun for several hours daily. Invariably there were 

 numerous dead eggs lying on top of the spawning beds or in the open 

 crevices in the gravel just beneath, and only when a depth of about 2 

 inches below the surface of coarse gravel was reached were any live 

 eggs discovered; but all or nearly all the eggs below this point, some- 

 times to a depth of 10 to 12 inches, were good. 



The minnows and small suckers found in trout streams after the 

 spawning season of the trout are of such size as to be unable to reach 

 the good eggs in the crevices among the gravel. Therefore any eggs 

 they obtain from the surface or just below must be dead before they 

 eat them, for it is well known that exposure to the direct rays of the 

 sun, at least during their early development, is almost invariably fatal 

 to trout eggs. Consequently any consumption of eggs by minnows and 



