Mating behavior in Thalamita picta (Brachyura: Portunidae) and comparisons with congeneric species

Abstract

Intermolt (hard shelled) female Thalamita picta, including ovigerous females, were observed to mate in the field and laboratory. Postmolt (soft shelled) stages did not initiate a mating response in males. Copulation in the laboratory lasted an average of 186.1±66.7 seconds (mean±S.D., n = 16) with no significant difference (P>0.1) in duration between pairs with ovigerous and non-ovigerous females. Further, duration of copulation did not differ significantly (P>0.1) between pairs in which the male was larger than the female and those in which the female was larger than the male. For the pre-copulatory maneuvering period (time between capture of the female and the initiation of copulation), although no significant difference was observed between ovigerous and non-ovigerous females (P>0.1), pairs in which the male was smaller than the female (248.6±180.5 sec, n = 9) differed significantly (P<0.05) from pairs in which the male was larger (75.3±39.6 sec, n = 7). Mating behaviors with the congeneric species T. sima and T. prymna are compared and discussed.