Study of sexual dimorphim in morphometric characters and some growth parameters of the fidder crab Austruca sindensis (Alcock, 1900) eastern coast of Bandar Abbas, Persian Gulf

Abstract

Introduction: The aim of this study was investigation sexual dimorphism in morphometric
characters and some growth parameters of Austruca sindensis on eastern coast of Bandar
Abbas (behind the airport) during January 2017 to December 2018.
Materials & Methods: Samples after collecting were moved to biology laboratory of
Hormozgan university for more study. 857 Individuals (457 males and 382 females) have
collected.
Result: Based on results, carapace width means of male crabs (9.48 ± 2.52 mm) was
obtained significantly more than carapace width mean of female crabs (8.47 ± 1.84 mm)
(P<0.05). Among the studied parameters, proportion of fifth and sixth abdomen width was
significantly more in females (P<0.05). The negative allometric growth was observed for
both sex. Also, the exponential value (b) estimated was obtained 2.92 for male crabs and
2.72 for female crabs (P<0.05). In this study, Asymptotic carapace width (CW∞), the
theoretical age at length zero (t0), maximum life span estimated 23 mm, -0.13, 2.6 year for
male and 19.8 mm, -0.1, 1.9 year for female. Also, growth rate (k) and mortality of female
were high in comparison to male crabs. The condition factor value of males (0.042±0.006)
was obtained significantly more than of females (0.034±0.006) (P<0.05). In addition,
variations in the condition factor rate were correlated with temperature.
Conclusion: In this study, the mortality rate of female crabs was higher than the mortality
rate of male crabs.