FISHERY BULLETIN: VOL. 70, NO. 4 



LOG 



100.0 



10.0 - 



1.0 - 



WHOLE WEIGHT 



10.0 100.0 

 ~T — I I I I I 1 1 r — I — I I r I I 



_i I I I I I I I 



1,00 o 



3) 



o 



o 



0.10 



0.01 



0.10 

 DRY BODY WEIGHT 



1.00 



Figure 2. — The fitted allometric curves for the shell 

 weight/dry body weight and dry body weight/whole 

 weight relationships in intertidal (I) and subtidal (S) 

 oysters. 



equations had significantly different log a values 

 (Figure 3) . The ratio between dry body weight 

 and soft body weight expresses the percent 

 moisture in the tissues. The fitted expressions 

 show that the percent moisture is almost con- 

 stant with size since the fitted b values approach 

 1. The percent moisture is 83.4% in the inter- 

 tidal oysters and 81.1% in the subtidal oysters. 

 The height/soft body weight relationships had 

 significantly different log a values, but the b 

 values were not significantly different (Figure 



3). 



The dry body weight/height relationships 

 were significantly different in respect to their 

 fitted log a values; the b values were not sig- 

 nificantly different. Significantly different log 

 a values, but similar b values indicate that the 

 fitted curves are almost parallel (Figure 4). 



The dry body weight/length relationships 

 were the only fitted data with both significantly 

 different log a and b values (Figure 4). 



No significant differences were found between 

 intertidal and subtidal oysters in the remaining 

 relationships, and no significant diflferences were 



found between samples when each sample was 

 calculated separately. 



Data for subtidal oysters tended not to fit the 

 allometric relationship as well as the intertidal 

 oyster data. This tendency is indicated by the 

 lower 7-^ values for subtidal models, where 

 r^ X 100 is an estimate of the percent variability 

 of the data explained by a model. The lower r^ 

 values for subtidal oyster relationships may be 

 partially attributed to the fact that fewer ob- 

 servations were made on this group of oysters. 



DISCUSSION AND CONCLUSION 



The quantitative relationships between the 

 various parameters of weight and linear size for 

 intertidal and subtidal oysters of diflferent sizes 

 have never been adequately described previously. 



All significantly different relationships be- 

 tween intertidal and subtidal oysters involve dry 

 body weight. Since a large proportion of the 

 nutrients and energy available to the secondary 

 consumers in the oyster food web is contained 

 within the body of the oyster, this parameter 

 is important in productivity studies. It is also 

 important that the prediction of dry body weight 



SOFT BODY WEIGHT 



10.0 — 



I I I I 1 1 



0.0 



0.10 

 DRY BODY WEIGHT 



1.00 



Figure 3. — The fitted allometric curves for the dry body 

 weight/soft body weight and height/soft body weight 

 relationships in intertidal (I) and subtidal (S) oysters. 



1124 



