De Lestang et al.: Reproductive biology of Portunus pelagicus 



751 



T3 

 Q. 

 0) 



Leschenault Estuary 



Koombana Bay 



Peel-Harvey Estuary 



./ 



/ 



Cockburn Sound 



Shark Bay 



100 



50 





 100 



50 





 100 



50 



= 

 100 



50 





 100 



50 



2 3 4 5 6 

 Log carapace width (mm) 



96 mm 

 (602) 



100 



50 





 100 



50 





 100 



50 



= 

 100 



50 





 100 



50 



88.0 mm 

 J/^ (76) 



J 



86 5 mm 



(67) 



97,0 mm 

 f (813) 



40 80 120 160 

 Carapace width (mm) 



40 80 120 160 

 Carapace width (mm) 



Figure 4 



Maturity data for male Portunus pelagicus in the five bodies of water sampled in Western 

 Australia. (A) Relationship between the natural logof length of the dorsal propodus of the 

 largest cheliped and the natural log of carapace width. Logistic regressions and their 95% 

 confidence limits were fitted to percentage contributions of those adult males, which, at 

 each size, were (B) morphometrically mature and (C) possessed mature gonads. Arrows 

 and measurements denote CW^^'s and the numbers in parentheses refer to the number 

 of crabs used to create the regressions. 



crabs in Shark Bay did not peak sharply at any time and 

 were > 1 g in all but two of the ten months in which this 

 embayment was sampled (Fig. 5). 



The mean monthly gonad weights of male crabs with a 

 standard carapace width of 118.4 mm, as determined by 

 ANCOVA, varied little and never exceeded 1 g in any of 



the five bodies of water (data not shown). However, they did 

 reach their maxima at a similar time of the year, i.e. late 

 summer (February) or early autumn (March), in the four 

 bodies of water on the lower west coast of Australia. 



The monthly percentage contributions made by oviger- 

 ous female crabs from all mature female crabs in Koom- 



