Claw regeneration, waving display and burrow characteristics of Austruca perplexa (H. Milne Edwards, 1852) (Brachyura, Ocypodidae) from southern Thailand

Abstract

We studied the effects of claw regeneration on male waving rate and burrow characteristics (i.e., important mate choice criteria) by examining the waving rates and burrow characteristics (diameter, total and horizontal lengths, depth, volume, maximum width, entry and burrow angles, and presence and location of chambers) of large-sized original-clawed males (OCMs) and regenerated-clawed males (RCMs) of Austruca perplexa (H. Milne Edwards, 1852). Female burrows were also examined. The results showed that female burrows were smaller than male burrows, with no chamber and, thus, female burrows are not used for breeding; however, 80% of RCM burrows, and 65% of OCM burrows, had chambers. Other characteristics were not different between RCM and OCM burrows, except for maximum width, which was larger in RCM burrows. The waving rates of OCMs and RCMs were not different. Our results indicate that claw regeneration do not have detrimental effects on male waving rate and burrow characteristics.

Size‐dependent mating preference of the male fiddler crab Austruca perplexa

“…Another reason could be the operational sex ratio of the population. The sex ratio (females to males) of A. perplexa on the mudflat surface is about 1:2.1 at our study site during the reproductive season (Tina et al, 2018b). When the sex ratio is male-biased, males will encounter few females, and hence, there is a low probability that a male will find another receptive female after rejecting the first one.…”

“…However, this is not the case in A. perplexa ; males of this species form pairs with one female inside his burrow and after the pair formation, he seals the burrow entrance with a plug of sediment (Nakasone & Murai, ). Tina et al () also examined the male burrow characteristics in A. perplexa and observed only one breeding chamber in each male burrow; it indicates that more than one female cannot accommodate inside one male burrow.…”

“…perplexa; males of this species form pairs with one female inside his burrow and after the pair formation, he seals the burrow entrance with a plug of sediment (Nakasone & Murai, 1998). Tina et al (2018b also examined the male burrow characteristics in A.…”

“…In fiddler crabs, males court females by waving their major claws, which is a costly behaviour (Backwell, Jennions, Christy, & Passmore, 1999;Matsumasa & Murai, 2005;Murai, 1992). In many species (e.g., Leptuca pugilator, L. beebei, Austruca annulipes, A. perplexa), males build breeding burrows and wave major claws towards females to attract them into the burrows (Backwell & Passmore, 1996;Christy, 1982Christy, , 1987Christy, , 1988Christy & Schober, 1994;Tina, Jaroensutasinee, & Jaroensutasinee, 2018b). Females select males based on their body and claw size, waving rate and burrow quality.…”

Temporal variations in the air, soil, and fiddler crab (Austruca perplexa) burrow temperatures in southern Thailand

“…Both males and females of this species build burrows where males mostly build breeding burrows, and females build temporary refugee burrows. The lengths of male and female burrows are approximately 246 mm and 187 mm, and depths are 192 mm and 140 mm, respectively (Tina et al 2018). They are active on the surface during diurnal low tide.…”