88 SALMON AND TROUT IN ALASKA. 



In Quadra fish taken in 1903, about one month earher than the 

 1904 lot, the length curve shows much variation (see diagram g). 

 The average length- is nearly 20 mm. greater than in 1904, and the 

 curve zigzags between 500 and 570 mm. across the 10 per cent line, 

 while in 1904 it shows a single rise to about 17 per cent on 500 and 

 510 mm. The difference in average length, weight, and depth of 

 Quadra fish in the two seasons of 1903 and 1904 is very close to that 

 of Yes Bay fish for the same years. The curves, however, are quite 

 unlike, that of Quadra for 1903 being compound, while that for Yes 

 Bay is simple. It was noted that the Quadra fish of 1903, though 

 examined later than those of Yes and Karta bays, were less developed 

 sexually. In almost all cases the curves for the females, though quite 

 similar in general form, exliibit less complexity than the curves for the 

 males. (See tables 4 and 4a, p. 84.) In no case is the curve of such 

 a character as clearly to indicate fish of different ages, though it is 

 possible that such curves as that for Yes Bay in 1904 may be so 

 accounted for. The maxima in this case, separated by 60 mm. (80 

 total length) and 2 pounds, would seem to be about what might be 

 expected for the difference between a 3-year and a 4-year fisli. In 

 the females the maxima of length are separated by the same interval 

 and the much lower percentage of the lower maximum accords with 

 what is known of the development of the king salmon in captivity, 

 in which the males exhibit much the greater precocity. 



Of the occurrence of the grilse form, or Arctic salmon, we know 

 little, for the reason that many doubtless pass the meshes of the nets, 

 and many are unreported by the fishermen, since they are not taken 

 as "counts." At Quadra, of the sockeyes delivered at the scow 

 about 1 in 300 were grilse. This is, perhaps, not far from the average 

 ratio in the Loring district. They were not noted in unusual number 

 at Dolomi. The Moira Sound fish examined in 1903 are too few to 

 be of any value in the present comparisons. 



The increase of relative depth in the later fish may indicate only 

 the change incident to sex maturation. It carries with it, however, 

 a corresponding increase in weight. If it is not a typical. form, but 

 merely a sex character, then the early run ascends the stream with a 

 smaller amount of tissue deposit than later runs, else they do not 

 first enter the bay for the purpose of ascending the stream, but 

 return again, if not liindered, to the feeding grounds. 



Such observations as could be made in opening the fish for deter- 

 mination of sex did not indicate that the difference in sex maturity 

 of the different parts (seasons) of the run are material until after the 

 main body has arrived. The late arrivals — the last week or so of 

 the regular run and belated sections — do show marked advance of 

 sex maturity. It is probable that careful measurements would 

 show a gradual increase in relative maturity, but not proportionate 



