SALMON AND TROUT TN ALASKA, 55 



may be found about the mouths of the streams in brackish water 

 perhaps soon after their descent of the stream. It may be they 

 remain about the streams for a time to accustom themselves to the 

 salt water, but this is not evident in case of the fr}^. The sea-run 

 examples are readily distinguished by the silvery appearance and 

 usually by the greater depth of body which follows habitual disten- 

 sion of the stomach. In some cases, while near in shore, insects 

 appear to continue a staple article of diet, as in the fresh water. 

 The cohos feed less on Crustacea than the sockeyes, perhaps inhabit- 

 ing slighter depths; correlated to this is the abundance of small fishes 

 found in their stomachs — sticklebacks in brackish water and herring 

 and sand launces in more open regions. 



From the catches at Naha and Yes bays it would seem that the 

 cohos continue to school after reaching salt water. The results of 

 the seine hauls indicate that the different species of salmon school 

 together, or at least in the same waters. 



DOG AND HUMPBACK SALMON. 



On May 29, 1903, a small school of salmon, about 50 individuals, 

 was seen along the shore about 1 mile below Naha Bay. Seven of 

 these were secured — 5 humpbacks 42 mm., and 2 dog slightly larger. 

 The former were feeding on small Crustacea and pteropods, the lat- 

 ter on Crustacea and insect larvae. 



On July 1 and 2 a few dog salmon fingerlings were taken in the net 

 at station 2. These ma3^ have been either fishes that had remained 

 in Roosevelt Lagoon since early spring, or stragglers from the bay 

 coming in on high tide. Ten were males, averaging 56 mm., and 4 

 females, averaging 62. Those with food had been taking insects. 

 (See also p. 47.) 



At Karluk June IS the fry of both dog and humpback salmon were 

 abundant along the beach. Six preserved examples of the dog aver- 

 age about 50 mm., and contained insects, crustaceans, and small cot- 

 toid fry. Thirteen humpbacks saved average about 47 mm. ; of the 

 6 larger ones examined 4 contained crustaceans, the other 2 nothing. 



Jul}^ 24 there were saved from the cannery seines 5 dog-salmon 

 young, averaging 83 mm. (70-100), which contained a few insects 

 and small fishes (blennics), but mainly crustaceans. Also 47 hump- 

 back young, averaging 77 mm. (60-95), the main food in which 

 was copepods, but in addition were found flies, insect larvae, amphi- 

 pods, and in a few cases small fry, probably Lumpenus, up to 18 mm. 

 in length; 1 stomach contained 22 of these. Only the following 

 collections were made by the Albatross: 



In Alert Bay, British Columbia, June 5, 1895, about 50 dog salmon 

 small fingerlings were taken, along witii a number of small sockeyes; 

 these averaged about 40 mm. and contained only small Crustacea. 



