60 SALMON AND TROUT IN ALASKA. 



vicinity of Karluk and near Union Bay, Cleveland Peninsula; but 

 the identification of these catches has not been authenticated. The 

 only pertinent fact regarding their place of residence after leaving 

 the vicinity of the parent streams, if they leave it, is that the pres- 

 ence of adult fish is first noted at the time when they are apparently 

 rounding some point in their progress from more open water. Such 

 places are Point Higgins, at the entrance to Behm Canal ; Cape Cha- 

 con, at the lower end of Clarence Straits, and Otter and Sheringham 

 points, on Juan de Fuca Straits. Karluk River is apparently 

 approached directly from the open straits. 



APPROACH OF SCHOOLS. 



The presence of salmon can be noted only by their habit of leaping 

 from the water as they approach the land. It is often possible by 

 this means not only to recognize the presence of a school, but also to 

 distinguish the species. In jumping, salmon do not leave the water 

 with their ventral surface downward, as.do flying-fishes. They always 

 jump side wise with one side at an acute angle to the water surface. 

 Sockeyes seldom entirely clear the water, but let the tail drag for some 

 distance, fall on the side, and then perhaps skim the water for a short 

 space. They may make two or three successive jumps, apparently at 

 random and in varying directions. Cohos usually leave the water 

 entirely, falling back on the caudal peduncle held rigid wdth the fin 

 directed upward. The tail may then drag through the water a short 

 distance till the fish falls on its side and disappears. The humpbacks 

 jump very agilely and characteristically. They leap clear of the 

 water, shaking the tails vigorously while in the air, sometimes turn- 

 ing completely with a corkscrew motion. On falling they strike on 

 the side. 



The cause of this jumping has been much discussed. It was noted 

 that a school of kings feeding in Naha Bay in December, 1903, jumped 

 in much the same manner as fish on the way to the spawning grounds, 

 but apparently not so frequently, probably because of the small num- 

 ber of individuals under observation. The sockeye travels in large 

 and compact schools when approaching the spawning regions, and the 

 jumping should be easily accounted for in the natural playfulness of 

 groups of animals or the struggle for preferred position. Stomachs of 

 netted fish often contain salmon scales and teeth, the latter frequently 

 the individual's own. But these are doubtless swallowed during the 

 struggles in the net and not by reason of previous combats. 



Under certain conditions the schools exhibit little tendency to 

 jump. In 1903 large numbers of sockeyes entered Karluk River 

 without such announcement. Of course it is not known whether this 

 species feeds in schools in salt water, or whether it is only the approach 

 of sex maturity that impels the gathering into schools. From the 



