The fishes of the Danmark Expedition. 669 



the end of June already ice-free water is present along the banks 

 of the lake and though there is a teeming life here of Apiis glacialis 

 and other Entomostraca, larvae of flies etc., I saw no trace oï Salmo 

 alpinus; at this time however it was often seen making rings at the 

 surface when snapping after food in the smaller lakes where it lives. 

 It is only in the beginning of July that the open water has spread 

 out so far in the lake, that the large fish (which in winter must be 

 considered to live in deeper water) can come into the banks and I 

 now often saw them strike up in the water, especially near where 

 the river leaves the lake. As soon as the outlet began to melt I 

 set put nets across it, without getting any fish however in the first 

 few days; but as soon as the water began to flow (4—5/7) down the 

 river to the sea, I obtained a number of fish in the net. At this 

 time and from now onwards I saw nothing of the fish in the lake 

 as before; probably because they are no longer compelled to stay 

 about the outlet but can continue their migration out into the sea. 

 Later in the summer the best fishing-place was at the outlet of the 

 river into the sea; and so numerous were the fish, that as many as 

 50 — 100 could be taken in one net in one day. In August the 

 migration was at its maximum and in September it was mainly in 

 the direction from the sea up into the lake, until it ended when 

 the river began to freeze over in the middle of the month. The 

 smallest specimen I have seen was 20 — 25 mm, which was taken in 

 the stomach of a fish ca. 600 mm long (Hvalrosodden, Aug. 1907); 

 though much decomposed it was easily recognized from the large, 

 round head, large eyes and the appearance of the occipital and 

 dorsal pigment. More important however was the capture of a 

 young specimen 30 mm long (probably the young of the year) by 

 the bank of the lake above the harbour on 29. — 7. — 07. From this 

 size and upwards to ca. 200 mm it is extremely common in shoals 

 of 5 — 10, swimming about in the shallow water by the bank and 

 (especially' at night) striking up after the flies. Above ca. 200 mm 

 the fish seem to go about more singly, except when the period of 

 migration sets in (see above). The largest fish taken measured 

 700 mm. 



The following table, which refers to some of the fish measured, 

 shows the size and sex. 



males: 700, 690, 680, 670, 660, 650, 645, 565, 550, 510, 

 490, 440, 416, 185, 170, 150, 120, and 110 mm. 



females: 625, 520, 180, 178, and 157 mm 

 Regarding the spawning-time I have no certain observations; 

 the many large males which were taken in July and August had 

 the testes in various degrees of development, but none had running 



