GRISWOLD and SMITH: LIFE HISTORY OF NINESPINE STICKLEBACK 



Table 3. — Length frequency of the age-groups of female 

 sticklebacks taken in July 1968 from the Apostle Islands. 



Table 4. — Length frequency of the age-groups of male 

 sticklebacks taken in July 1968 from the Apostle Islands. 



Total 

 length 



(mm) 



Age-groups 



III 



40-41 

 42-43 

 44-45 

 46-47 

 48-49 

 50-51 

 52-53 

 54-55 

 56-57 

 58-59 

 60-61 

 62-63 

 64-65 

 66-67 

 68-69 

 70-71 

 72-73 

 74-75 

 76-77 

 78-79 

 80-81 

 82-83 

 84-85 

 86-87 



Average 

 length 



Number 

 offish 



52.3 



102 



66.5 



157 



73.8 



70 



76.8 



12 



78.5 

 3 



Growth in Length 



The relationship between total fish length 

 and otolith length was estimated from otoliths 

 of 320 males and 488 females. Body lengths 

 at each 1.0-mm interval of otolith length were 

 averaged, and the mean total lengths were plot- 

 ted against the otolith length. The relationships 

 for fish from stations 2 and 3 were very nearly 

 the same, but the relationship for males and 

 females were empirically quite different (Figure 

 4). Second degree polynomial regressions were 

 fitted to these data and the resulting equations 

 were : 



Males Y = -25.864 + 2.U6X - 0.011^2 



Females Y = -25.075 + 2.131Z - O.OOIOX^ 



where Y = total fish length (mm) and 

 X = projected anterior otolith 

 radius (mm). 



Coefficients of determination (r^) values were 

 0.978 and 0.958 for male and female equations, 

 respectively. An analysis of covariance showed 

 the elevation was significantly different at the 



Total 

 length 

 (mm) 



46-47 

 48-49 

 50-51 

 52-53 

 54-55 

 56-57 

 58-59 

 60-61 

 62-63 

 64-65 

 6667 

 68-69 

 70-71 

 72-73 

 74-75 



Average 

 length 



Number 

 of fish 



>- 



Q 

 O 

 HI 



_l 

 < 



o 



< 



UJ 



s 



Age-groups 



5 



1 



4 



2 



11 



12 



11 



7 



13 



7 



4 



1 



51.8 



78 



II 



5 

 5 

 8 

 18 

 8 

 4 

 2 

 4 



66.7 



54 



III 



69.4 



10 20 30 40 50 60 70 80 



PROJECTED ANTERIOR OTOLITH RADIUS (MM) 



Figure 4. — Body length-otolith length relationship for 

 Apostle Islands ninespine sticklebacks. Solid line, males; 

 dashed line, females. 



0.01 level (Fj .^g - 48.32). Therefore, growth 

 parameters were calculated separately for each 

 sex. In Figure 4, the plots were extrapolated to 

 intercept the body-length axis at 6 mm, the 

 length of otolith formation of Alaskan three- 

 spine sticklebacks (Jones and Hynes, 1950). 



Growth rates were determined for females 

 for the 1962 through 1967 year classes (Table 



1043 



