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30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 



MIDEYE-HYPURAL PLATE LENGTH (CM.) 



at the mouth of the creek. The ovaries were 

 removed from the fish, placed in a cloth bag, 

 and boiled in water until the ova had hardened 

 and could be easily separated from the mem- 

 branous connective tissues. The eggs were 

 counted by use of coLinting boards (see Helle 

 et al., 1964). The MEHP length of each fish 

 was n-ieasured. 



I determined the relation between number of 

 eggs and length. In 1963 the eggsineach ovary 

 were counted separately so that a comparison 

 of number of eggs in the right and left ovaries 

 could be made. The number of eggs retained 

 in the body cavity after spawning was de- 

 termined by a periodic examination of car- 

 casses on the spawning grounds. 



Figure 8. — Comparison of MEHP lengths of pink salmon 

 from the early and late runs in two intertldal areas (main 

 stream of Olsen Creek and Little Creek), 1963. (See 

 legend of figure 7 for explanation.) 



Creek were significantly shorter (P < 0.05) 

 than females in the main stream (fig. 8). In 

 the parent year (1961) the mean length of pink 

 salmon spawning in Little Creek was shorter 

 than of those spawning in the main stream, 

 but the difference was not significant (Helle 

 et al., 1964). 



Relation between Fecundity and Length 



In 1962 fecundity was determined for both the 

 early and late runs. Females were collected 

 periodically in 1963 and combined without 

 regard to early or late runs because the data 

 collected in 1961 indicated no difference in 

 the fecundity of the two runs (Helle et al., 

 1964). 



Relation of MEHP Length to Length from 

 Mideye to Fork of Tail 



Although the MEHP measurement is most 

 appropriate in Olsen Creek because of the 

 advanced maturity of fish sampled on the 

 spawning grounds, other investigators com- 

 monly use the MEFT (mideye to fork of tail) 

 measurement. To relate the two values, in 

 1962 and 1963 we collected 97 unspawned fe- 

 males at the mouth of Olsen Creek and 

 measured both the MEHP and MEFT lengths 

 on each fish with a caliper rule to the nearest 

 millimeter. The relation is Y = 4.7 + 1.0 IX, 

 where Y is the expected MEFT length in 

 centimeters and X is the MEHP length in cen- 

 timeters (fig. 9). 



FECUNDITY 



Female pink salmon were collected for 

 fecundity determinations from the early and 

 late segments of the runs to Olsen Creek in 

 1962 and 1963, without reference to spawning 

 area. The intertidal and fresh-water portions 

 of the runs cannot be sannpled separately 

 because many females expel some of their 

 eggs before they reach their "home" spawning 

 area. The females in my sample, which were 

 captured in a beach seine at the mouth of 

 Olsen Creek, were identified as early or late 

 on the basis of the time of their appearance 



1962 . --In 1962 the mean fecundity of 49 

 females from the early run was 1,815 eggs, 

 and the mean length was 43.0 cm.; the nneans 

 for 41 females from the late run were 1,846 

 eggs and 43.5 cm. (table 5). The relation be- 

 tween the number of eggs and the mean length 

 was low but significant for early- run females 

 (r = 0.347) but not significant for late-run 

 females (r = 0.294). The smaller range in 

 length of late-run females may account for this 

 lack of correlation for the late run. Foerster 

 and Pritchard (1941), who compared the re- 

 lation between number of eggs and length in 

 pink and sockeye salmon, Onco rhynchus nerka , 

 found that the correlation coefficients were 

 significant for both length and weight but were 

 much lower for pink than for sockeye salmon. 

 They suggested that the difference was due 

 partly to the narrower range in size of pink 

 salnnon. 



The relation between length and number of 

 eggs for the females from the early and late 

 runs combined in 1962 is shown in figure 10. 

 The mean length of the 90 females was 43,2 

 cm., and the mean fecundity was 1,829 (table 5). 

 The relation between number of eggs and length 

 was highly significant (r = 0.335). The mean 

 length of 50 females (early and late runs 

 combined) sampled in the parent year (1960) 

 was 43.0 cm., and the mean egg content was 

 1,815 (Helle et al., 1964). The relationbetween 

 number of eggs and length for the 50 fish in 

 I960, however, was not significant (r = 0.210), 



14 



