I04 



THE SEA-TROUT 



of scales, the shape of the tail, and the number and arrangement of the small 

 black spots : it is most exceptional to find on salmon any black spots below 

 the medial line behind the posterior edge of the back fin.i 



The actual description of a sea-trout smelt which was taken from 

 the river Leven on ist March, 1913, is as follows: — Length, over all, 

 9^ inches, of which the head occupied 2 inches and the caudal rays 

 I J inches; girth, at dorsal fin, 4J inches; weight 6 ounces. Body 

 colour, a pronounced blue on the back shading towards the lateral line 

 to a pale blue and thence to clear white on the under parts. Dark 

 cruciform spots closely speckled on the skin both above and below the 

 lateral line. The silvery scales, counted in the oblique line formerly 

 described, clearly numbered 14. The scales were easily removed and 

 beneath them 9 parr marks were faintly seen on each side of the fish. 

 The fins shaded from a pale yellow in the pectorals to a still paler yellow 

 in the ventral and anal fins. The dorsal fin was a dusky yellow closely 

 spotted with dark spots, and the dusky adipose fin had a reddish tinge 

 on its margin. The dusky tail was deeply forked. I am able to give 

 a coloured drawing (Plate VIII) of one of these exceptionally big 

 smolts. The specimen figured measured 9 inches in length. 



I have seen in other districts ascending whitling which were scarcely 

 larger than the smolt figured, but Loch Lomond whitling, which are 

 noted for their exceptional size and quality could hardly be so small. 

 The fish was unmistakably a sea-trout smolt engaged in a leisurely 

 descent to the Clyde estuary. 



The " run," as it is called, of descending smolts begins intermit- 

 tently as early as February — in the Leven a sea-trout smolt has actually 

 been got as early as January — and gradually increases during March, 

 the main body descending towards the end of April, after which the 

 run again becomes intermittent in May and practically ceases in June. 

 Rut T have evidence that smolts may descend very much' later in the 



1. From " ITvdrlodos adsldllos lakseorret-0(^ roieynj^el fra [hinanden," |by Hartig Hilitfeldt- 

 Kaas. Christiania (1905). 



