Surface mating influences chimney/burrow characteristics of Uca rosea (Tweedie, 1937) (Brachyura, Ocypodidae) in southern Thailand

Abstract

We investigated how surface mating affects the characteristics of chimneys (diameter, height, and thickness) and burrows (total length, horizontal length, total depth, volume and shapes) in Uca rosea (Tweedie, 1937). In U. rosea, surface mating is the main mating mode, and females incubate eggs inside their own burrows. We investigated 73 randomly selected burrows with chimneys (36 females, and 37 males). We observed that chimney and burrow characteristics, except for burrow/chimney diameter, were greater in females than in similar-sized males. The burrows were I- and J-shaped, with a higher number of J-shaped burrows in females and a higher number of I-shaped burrows in males. J-shaped burrows were longer and deeper, had greater volumes, and had higher and thicker chimneys, than I-shaped burrows. Chimney characteristics were positively correlated with burrow characteristics. Our results indicate that U. rosea female burrows are used for breeding, and male burrows are used for temporary stays.