Resurrection of Gelasimus variegatus Heller, 1862, A Fiddler Crab Closely Related to Austruca bengali (Crane, 1975) and A. triangularis (A. Milne-Edwards, 1873) (Decapoda, Brachyura, Ocypodidae), from the Bay of Bengal, Indian Ocean

Abstract

The identity of the fiddler crab, Gelasimus variegatus Heller, 1862 (type locality: Madras, India), has long been uncertain. Examination of specimens from the Bay of Bengal shows that it is a valid species belonging to the genus Austruca Bott, 1973. Austruca variegata (Heller, 1862) can be separated from the closely related A. bengali (Crane, 1975) and A. triangularis (A. Milne-Edwards, 1873) by characters of the carapace, orbital floor, major and minor chelae, male first gonopod, vulva (female gonopore), gastric mill, and coloration in life. The three species are also supported by genetic data (nuclear 28S rDNA, mitochondrial 16S rDNA and cytochrome oxidase subunit I (COI)). Biogeographically, A. variegata is distributed in the Bay of Bengal and reaches to the Laccadive Sea; A. bengali is present in the Andaman Sea; and A. triangularis is widely distributed in the West Pacific.