THE BROOK TROUT. 



DESCRIPTION OF THE FISH. 



The brook trout or speckled trout {Sali-elijiusfontiuaJis) is oue of the 

 most beautiful, active, aud widely distributed of the American trouts. 

 It jirefers clear, cold, rapid streams, and belongs to that group of trout 

 known as charrs, characterized by the presence of round crimson spots 

 on the sides of the body. Other members of this class are the saibling 

 or charr {Salvelinus alpimis) of Europe and Greenland; the Sunai^ee 

 trout {S. alpinus aiireolns), found in parts of ^ew Hampshire and 

 Maine; the blueback trout {S. oquassa) of the Eangeley Lakes in Maine, 

 and the Dolly Varden trout, red-spotted trout, or bull trout (*S'. malma) 

 of the Pacific States and Alaska. The lake trout also belongs in this 

 group. 



The general form of the brook trout's body varies considerably, some- 

 times being elongated and sometimes rather short, but the usual depth 

 is about one-fourth or one-fifth of the length. The head is large and 

 blunt, aud is contained 4i times in the body leugth. The large terminal 

 mouth is provided with teeth on the jaws, tougue, and palate bones, 

 and also with a small patch on the vomer. The eye is placed high in 

 the head; its diameter is about one sixth the length of head. The gill- 

 rakers on the first arch number about 17, of which 11 are on the lower 

 arm. The scales are very small and numerous; about 230 are in the 

 lengthwise series, and 35 above and 35 below the lateral line. The 

 dorsal and anal rays are 10 and 9, respectively. The tail is square or 

 slightly lunate in the adult, forked in the young. 



There is considerable variation in the color of the brook trout, 

 dependent on local conditions, sex, and age. The head, back, aud 

 sides of the body, dorsal and caudal fins are of a grayish or greenish 

 color; the back, head, dorsal, and base of caudal are mottled with dark 

 green or black. In the male there is a reddish band along side of belly. 

 Along the middle of the side there are numerous round light-red spots 

 surrounded by whitish or light-brownish circular areas. The lower fins 

 are dusky, with a pale or cream-color anterior border bounded by a 

 black streak; remainder of fin often red in breeding males. 



The brook trout may be distinguished from the other charrs by the 

 dark-brown or black marbliugs on the back and the general absence of 

 spots ou the back. 



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