704 



Fishery Bulletin 102(4) 



Blue 10 ° 

 crab 



Lady 

 crab 



Rock 

 crab 



Percent volume 



40-59 60-79 80-99 100-119 120-139 140-159 160-185 

 100 



100 



40-59 



60-79 



80-99 



100-119 



120-139 



Carapace width classes (mm) 



Figure 9 



Percent volume of prey I of the 12 categories I by 10- or 20-mm size classes 

 of blue, lady, and rock crabs, all seasons and strata. Codes for prey taxa 

 are from Table 3. 



male and female lady crabs with male rock crabs were 

 the lowest in the matrix (0.149 and 0.186). 



The spatial niche breadths of lady crabs were larg- 

 est (7.320 and 7.324) (a result of their nonaggrega- 

 tive distribution throughout the study area), whereas 

 the other two species tended to aggregate in certain 



locations, particularly in or near channels. Female 

 rock crabs also had a broad spatial niche, although 

 they were caught much less frequently than the other 

 groups. Spatial overlap was highest within species, 

 particularly between male and female lady crabs 

 (0.908). 



