14 



Fishery Bulletin 89|1), 1991 



gonadal condition, as described by the 

 RGI of Erickson et al. (1985) in which 

 gonad weight has been standardized by 

 female somatic weight, did not vary with 

 female size (Table 3). The RGI did differ 

 among years in concert with size-adjusted 

 variations in fecundity; mean RGI in 1984 

 was about 14% lower than the RGI aver- 

 aged over the other four years (Tables 2, 

 5). An identical pattern of annual varia- 

 tion in gonadal condition is observed if" 

 the classical gonadal index (GSI = [G/W] 

 x 100) is used as the dependent variable 

 in ANCOVA instead of the RGI. 



Potential biases 

 of condition indices 



Table 6 



Least-squares regression parameters for length-weight relationships of adult 

 female queenfish in each a of the study years. Ordinary least-squares regres- 

 sions were calculated for the double-log transformed equation, InW = lna + 

 blnSL, where lna is the intercept and b is the slope. 



Intercept 



Slope 



Year Estimate 



SE 



Estimate 



SE 



R 2 



N 



1979 

 1980 

 1984 

 1985 

 1986 



11.864 

 11.660 

 10.450 

 10.433 

 11.888 



0.246 

 0.178 

 0.378 

 0.206 

 0.616 



3.151 

 3.106 

 2.853 

 2.862 

 3.152 



0.048 

 0.036 

 0.077 

 0.042 

 0.124 



0.990 

 0.984 

 0.952 

 0.984 

 0.898 



44 < 0.0001 



126 <0.0001 



71 <0.0001 



77 <0.0001 



75 <0.0001 



"Estimated slopes of the InW - InSL relations differed among years 

 (ANCOVA; InSL x Yr interaction: F 4393 = 6.10, P<0.0001). 



These differences in somatic and gonadal conditions 

 were not the result of year variations in condition- 

 selective collection methods. Lampara-seined fish com- 

 prised 84-100% of the specimens examined for condi- 

 tion in each year; among non-lampara fish, a maximum 

 of 14% of the fish examined (in 1984) were collected 

 by otter trawl. The somatic conditions (K = 10 5 W/SL 3 ; 

 Le Cren 1951) of fish collected by lampara seine and 

 otter trawl during April-June 1984, the only period 

 when testable numbers of fish were collected using 

 more than one method, were indistinguishable (seine: 

 mean ± SE condition = 1.40 ±0.016; trawl: mean 

 ±SE = 1.39 ±0.010; Student's £ = 0.28, df = 151, 

 P = 0.78). 



Discussion 



Annual variations in body size 



Interannual variations in the body size of adult female 

 queenfish were marked, with the percentage contribu- 

 tion of large fish varying tenfold and mean somatic 

 weights of the nearshore female stock varying by 25% 

 over the study period. Clearly, potential year effects 

 on fecundity and other size-sensitive variables are con- 

 founded with the effects of annual variations in body 

 size, necessitating the use of size as a covariate in 

 analyses. 



Fecundity and female body size 



During each of the queenfish spawning seasons moni- 

 tored, batch fecundity was positively related to female 

 body size, especially somatic weight. The overall mean 

 value of b in the equation, F = aW h was 1.2087, which 

 is significantly greater than unity. 



I 



■o 



ITS 



c 

 o 

 O 



/3 3.5 4 4.5 5.0 



Ln Somatic Weight (g) 

 Figure 3 



Relationship between the log of ovary weight (ln G) and log 

 female somatic weight (In W) during each of the five study 

 years. For illustration, mean ovary weight data ( + 1 SE) are 

 plotted for each 10-g weight class. The equation. G = aW 

 (in log-linear form as InG = lna + blnW), and its summary 

 statistics are provided for each fitted regression line. 



