PARR AND SMOLTS 



103 



Salmon. 

 The extremity of the pectoral fin 

 when stretched flat against the side 

 will reach a line drawn from the 

 anterior edge of the dorsal fin. 



The adipose fin has no red colour. 



The scales are larger and less in 

 number than in the case of the 

 trout. In a slanting line between the 

 posterior edge of the adipose fin and 

 the medial line there are usually 1 1-12 

 and exceptionally 13 scales. 



Before the migratory colouring is 

 assumed, the colouring of the parr is 

 similar to that of small beck trout, 

 with one row of large, distinctly red 

 spots along the medial line, and often 

 with some smaller red spots above and 

 below this line. There are also a 

 number of small dark spots spread 

 over the whole body above the medial 

 line, with a lesser number below. 



What is especially characteristic of 

 the parr is the regular row of large 

 blue-grey blotches, even in breadtih, 

 about 8-13 in number, and about i to 

 2 diameters of the eye wide, which 

 contrast remarkably with the white 

 colour of the under portion of the 

 body. They resemble the smudges 

 which would be made by fingers 

 smeared with blue-grey paint. 



The smolt dress differs from the 

 parr colouring onlv in the fact that a 

 silvery sheen covers over the original 

 colouring, which latter shows through 

 the semi-transparent silvery coat, and 

 little by little the original colouring is 

 less and less visible, but so long as the 

 smolt remains in fresh water the parr 

 colouring can still be distinguished, 

 and especially in certain angles of 

 light. 



There are usually from 2 to 4 black 

 spots on the gill-covers. 



Trout. 

 The pectoral fins when stretched 

 out will not reach a perpendicular line 

 drawn downwards from the anterior 

 edge of the dorsal fin. 



1 he end of the adipose fin is usually 

 tinged with red or orange. 



The scales are smaller and more 

 numerous. In a slanting line drawn 

 between the posterior edge of the 

 adipose fin and the medial line there 

 are usually 14-16 scales and occasion- 

 ally more. 



The colouring before the migratory 

 dress is assumed is more variable than 

 with the parr. In addition to the red 

 spots on the sides, which are usually 

 in three rows, one generally finds a 

 large number (exceptionally a few) 

 small dark spots scattered over the 

 back and sides of the fish, with a 

 relatively large number below the 

 medial line. 



In place of the characteristic "finger 

 marks" of the parr, on the trout there 

 are fewer blotches and they are much 

 more irregular in shape. 



As far as the migratory dress is 

 concerned (in which condition sea 

 trout are to be found in large numbers 

 and of the same size as salmon smolts) 

 the trout is of a silvery white colour, 

 but it retains unchanged all the small 

 black spots both above and below the 

 medial line, but not the red spots. 

 This is the most distinctive difference 

 between salmon and sea trout in the 

 smolt stage. 



The black spots on the gill-covers 

 are usually more than 4 in number. 



The following points should be specially noticed : the shape of the head, 

 the size of the eye and the mouth in comparison with one another, the number 



