PARR AND SMOLTS 97 



fry stage the sea-trout has these less clearly defined in outline than 

 either the salmon or the trout. The parr marks of the young sea-trout 

 hardly remain visible after the first year, but they always appear with 

 more or less definiteness upon the skin when the scales are scraped off, 

 even after the fish has become a smolt. 



The sea-trout parr has also both crimson and dark spots, but the 

 dark spots vary greatly in number and appearance, and are far more 

 like those of young trout than those of young salmon. The sea-trout's 

 greenish-yellow tinted dorsal fin is usually boldly spotted. 



The colouring of the fins of the sea-trout varies very much but 

 generally the pectorals are yellow, tending sometimes to reddish-orange. 

 Sometimes they are quite dark and of a greenish-grey. 



Structurally, as regards head and jaw, the sea-trout parr differs 

 from the salmon parr just as the young trout differs from it, and both 

 as regards the lesser size and higher set position of the eye the sea-trout 

 parr and the young trout are alike in differing from the salmon parr. 

 So too the fins and tail of the sea-trout parr are more akin to those of 

 the young trout, but perhaps as a rule the tail of the former is the more 

 forked. 



Again, counting in the oblique line of scales formerly mentioned 

 the " 14-scale formula " obtains in the young sea-trout in contrast with 

 the "lo-scale formula " of the salmon. 



On the whole it will be recognised that while the salmon parr and 

 sea-trout parr have something in common, in detail the sea-trout parr 

 approximates perhaps more closely to the young trout. 



As to any differentiation between sea-trout parr and young trout, 

 account must be taken of Mr. Regan's dictum that " there are no 

 structural differences, and the young are indistinguishable." But that 

 there are some superficial distinctions there can be no question, although 

 these are never very constant in consequence of the endless variety of 

 marking and colouring that characterises both kinds of fish. 



