A new species of Parasesarma (Brachyura, Sesarmidae) from Western Australia, with a key to the species from Australia

Nine species of Parasesarma are currently recorded from continental Australian mangroves. The present study describes a new species, P. otiense sp. nov., from Western Australia. Parasesarma otiense sp. nov. occurs sympatrically with P. hartogi and P. holthuisi in the mangroves of Exmouth Gulf.

In both COX 1 and 16 S BI trees, the new species is well nested within Parasesarma, but divergent from other species. Morphologically, the new species is distinct from other Parasesarma in having eight asymmetric tubercles with the distal slope longer than the proximal slope on the upper surface of the cheliped dactylus. Parasesarma otiense is the tenth species of Parasesarma recorded from continental Australia, taking the number of species assigned to the genus Parasesarma to 59.

A key to the species of Parasesarma known from Australian waters is provided to aid in their identification.