A new species of freshwater crab of the genus Barytelphusa (Decapoda, Brachyura, Gecarcinucidae) from the Eastern Ghats of India

Abstract

A new species of gecarcinucid crab, Barytelphusa choprai sp. nov., is described here from the Eastern Ghats in Andhra Pradesh state of India. The new species differs from all three congeners by its convex and trapezoidal carapace, pale white colouration, and by a distinct structure of the male gonopod G1. It differs from its congeners by genetic distance (p-distance) in the range of 5.7-13.6% in partial mtCOI gene sequence. The habitat at the type locality is a slow flowing shallow stream with rocky substratum, covered with silt and debris, and devoid of aquatic vegetation.

Morphological and molecular identification of the freshwater crab, Barytelphusa cunicularis from Kanniyakumari, India

“…Accordingly, B. cunicularis, the candidate specimen of the present study, in spite of belonging to the same clade, seems to have diverged from the ancestral stock much earlier than that of its congeners, B. guerini and B. mccanni. This result is reminiscent of a recent report from Mandal et al (2022), wherein B. cunicularis is shown to have a distinct cladistic path, well separated from its congeners (3 strains of B. guerini and 5 strains of B. choprai).…”

“…In B. cunicularis, the carapace generally flat, but slightly convex at its anterior part, with antero-lateral margin well pinched off from the general surface; relatively large and sharp epibranchial tooth lying just above the postorbital cristae, with a small but distinct gap (Bahir and Yeo, 2007). The gonadal characters such as long and slender disposition of G1, with its moderate base with the curved terminal segment, and G2 was slightly pointed outwards (Alcock, 1909(Alcock, , 1910Mandal et al, 2022) are potential tools for distinct identification of the species cunicularis from its congeners. For the precise assessment of the phylogeny, Parsimony Analysis was also employed in this study.…”

“…The data on the Western Ghats has revealed the occurrence of 62 species distributed in 18 genera, under the family Gecarcinucidae. Among brachyuran crabs, the genus Barytelphusa (Gecarcinucidae) has so far been known to encompass three species such as B. cunicularis, B. guerini and B. th mccanni; of late, however, a 4 species, B. choprai has been reported from the Eastern Ghats of India (Mandal et al, 2022).…”