354 



Fishery Bulletin 94(2). 1 996 



Table 1 



Carapace width at 50% maturity ( W ft0 ) and mean carapace width of mature individuals ( W m ), in millimeters, by species, sex, and 

 area. Standard errors are shown in parentheses. Estimates for W 50 for C.japonicus were interpolated from a figure in the noted 

 source and are therefore approximate. 



Species 



C ta nnen 



C. angulatus 



C. japonicus 



Sex 



male 



female 



male 



female 



male 



female 



male 

 female 



male 

 female 



U 



It- 



Area 



Source 



C. tanneri 



85 90 95 100 



C angulatus 



110 



65 



,'n 



75 



85 



Carapace width (mm) 



Figure 7 



Fecundity is shown as a function of cara- 

 pace width for female Chionoecetes tanneri 

 (upper graph) and C. angulatus (lower 

 graph). The number of eggs was not sig- 

 nificantly related to size for C. tanneri, but 

 it was significant for C. angulatus and the 

 regression line is shown. 



Table 2 



Number and percentage of individuals examined in each 

 of three reproductive conditions for mature female C. tanneri 

 and C. angulatus. 



Reproductive condition C . tanneri 



C. angulatus 



3 (uneyed eggs) 

 4 (eyed eggs) 

 2, 5 (no eggs) 



33(79%) 

 

 9(21%) 



121 (86%) 



2(1%) 



17 (12%) 



did not differ significantly between species (Table 3; 

 X 2 =0.27, P=0.53). Most mature females were scored 

 as having shell condition 3 (Table 3), indicating that 

 they probably had not molted for at least 1 year and 

 likely have a terminal molt similar to that of the 

 shallower water species C. bairdi and C. opilio. Some 

 individuals of both species had molted so recently 

 that their exoskeletons were still pliable. Because 

 the puberty molt is usually associated with mating, 

 some mating must have occurred as late as July. 

 However, the primiparous (shell conditions 1 and 2) 

 females also had a surprisingly high percentage of 

 barrenness (C. tanneri — 60%; C. angulatus — 76% ) com- 

 pared with multiparous (shell condition 3) females 

 (('. tanneri— 16%; C. angulatus— 3%). For C. bairdi 

 and C. opilio, primiparous females are rarely barren 

 because mating and egg extrusion quickly follow the 

 puberty molt (Watson, 1970). Perhaps for C. tanneri 

 and C. angulatus, egg extrusion does not follow a 

 molt as closely as it does for shallower species, and 



