Revisiting the phylogenetic status of a field crab (Decapoda, Brachyura) from Chelari, Malappuram District (Kerala, India): an integrative approach through morphological and molecular taxonomy

Abstract

Abstract The phylogeny of field crabs has been under profuse discussion for several decades. At this juncture, this paper reassesses the “decades old” phylogenetic status of an edible field crab, hitherto referred to as Paratelphusa hydrodromous, inhabiting the paddy fields of Chelari village (Kerala, India). After Alcock’s (1910) description, there has hardly been any serious attempt at ascertaining its precise taxonomic status. Through an integrated approach, using parsimony analysis and molecular methods, the present study reveals the candidate form’s (species’) closer affinity to the genus Oziotelphusa. Comparison of morphological and molecular characteristics with its closest phylogenetic neighbours (O. biloba, O. wagrakarowensis, O. kerala and O. aurantia) has shown that the candidate form is a taxonomically distinct entity, qualified to be considered as an unreported species; its suggested revised nomenclature is Oziotelphusa chelarensis, reminiscent of the village Chelari. Further, the paper views the relevance of this taxonomic study from conservational angles as well.