44 BULLETIN OF THE BUREAU OF FISHERIES. 



characteristic of the scale growth. A more detailed study of much larger collections 

 might, however, discover special characteristics of growth or of scale record in the 

 different streams. The primary check appears in only one of the collections which 

 were made close to tidewater, the one from the Nestucca River. The check observed on 

 the scales of the specimens from Shasta River and Deer Creek (collected toward the 

 headwaters of these streams) is undoubtedly the same as the primary check noted in 

 upstream fish from the Columbia River basin. (See p. i8.) A band of intermediate 

 rings is characteristic of varying proportions of the fish contained in all of the collections 

 made near tidewater and is in every respect similar to the intermediate growth of the 

 Columbia River migrants. Although the available data are meager, it seems safe to 

 state that the history of the fish in these smaller streams is, in its general aspects, similar 

 to the history of young fish collected in the Columbia River at the same time of year. 



The three specimens taken near Hope Island, Puget Soimd, were the only chinooks 

 among some 70 specimens captured by hook and line in one of the fish traps located at 

 this point. The remaining specimens were yearling silver salmon averaging about 

 100 mm. in length. There is no means of knowing whether this is the normal propor- 

 tion existing between young silvers and young chinooks in this part of the sound at 

 this time of year. It may be that the young chinooks do not lead into the traps as 

 readily as the silvers; or they may be less willing to take the hook. These three chi- 

 nooks were, respectively, 130, 97, and 94 mm. in length. All were males. On examining 

 the scales it was surprising to find that, in spite of the negligible difference in size between 

 the two smaller fish, the smallest individual was a fry and the two larger ones both 

 yearlings. The record on the scales is perfectly clear, leaving no doubt as to the proper 

 interpretation. The scales of the two smaller individuals, differing but 3 mm. in length, 

 are reproduced in Plate IV, figures 6 and 7. The scales of the smallest individual show 

 no indication of stream growth, and there is no doubt that this fish migrated as a young 

 fry and that the scales represent a purely ocean type of nucleus in the process of forma- 

 tion. The scales of the fry show 13 rings, and the length of the anterior radius is 50. 

 The scales of the smaller yearling have 13 rings to the end of the first year's growth 

 and 5 in the intermediate growth. Those of the larger yearling have 19 rings to the 

 end of the first year and 8 in the intermediate band. The scale measurements are as 

 follows : 1 30 mm. specimen, 55 to beginning of the intermediate growth, total, 92 ; 97 mm. 

 specimen, 28 to intermediate growth, total, 47. 



The yoimg chinook from Half Moon Bay, Calif., is of particular interest, since it is, 

 so far as the author knows, the smallest individual which has been captured in the open 

 ocean at any distance from the mouth of the parent stream. Unfortunately, there are 

 no data as to the date of capture, except that it was previous to 1913. The specimen 

 presumably came from the Sacramento River, since at the time this was captured no 

 chinooks were known to spawn in the streams south of San Frandsco." This fish was 

 approximately 100 mm. long. The scales (PI. IV, fig. 8) indicate clearly a period of 

 life spent in the stream followed by a sharply demarked area representing ocean growth. 

 That part of the scale indicative of stream growth is precisely similar to the scales of 

 young migrating fish taken in the spring and summer on the lower Sacramento River 

 (PI. Ill, fig. 6). 



" Within tho past six or seven years a run ot chinook salmon has been established in the San Lorenzo River, Santa Cruz 

 Co., CallJ., by the late Supt. F. A. Shebley, of the Calilornla Fish and Game Commission. 



