Description of a new species of brackish-water crab of the genus Ptychognathus Stimpson, 1858 (Crustacea: Brachyura: Varunidae) from southern Taiwan

Abstract

The brackish-water crabs of the genus Ptychognathus Stimpson, 1858, the most diverse genus in the family Varunidae, inhabit the estuaries or seashores influenced by freshwater. Ptychognathus sakaii, a new species from Kenting, southern Taiwan, is described in this study, with a comprehensive key to the ten species of this genus from Taiwan. This new species is similar to its congeners, but can be distinguished mainly by the features of the carapace, ambulatory legs, and male first gonopods.

Keywords
Decapoda; morphology; Ptychognathus sakaii; species diversity; taxonomy