morphometric characteristics of the blue swimming crab, portunus pelagicus (linnaeus, 1758) from the persian gulf, bandar abbas, iran

in this study, some external morphometric characters viz. carapace width (cw) and length (cl), chelar propodus width (chw) and length (chl) and abdominal width (aw) and also body weight (bw) of the blue swimming crab, portunus pelagicus (linnaeus, 1758), were examined. relative growth and regression slope compared among these parameters between 151 males and 158 females. specimens were collected during one year on a monthly basis from the persian gulf waters, bandar abbas, iran. regression analysis between cw-bw and cl-bw demonstrated that males were 1.07 and 1.14 folds heavier than females, respectively. besides, females have 1.1 folds wider carapace in compare to males, revealed from considering the relative growth equation. regression between chl and bw demonstrated that chelars were significantly longer (1.44 folds) in bias to males. also regression analysis between aw and bw revealed that difference between male and female is significant, with wider abdomen in later (1.61 folds). considering the significant discrepancy between males and females, it is concluded that differences in these body parts may be related to reproductive adaptation for more efficiency.