Pinctadaphuketensis sp. nov. (Bivalvia, Ostreida, Margaritidae), a new pearl oyster species from Phuket, western coast of Thailand.

A new species of the genus Pinctada is described from samples collected from the east coast of Phuket Island, Thailand in the Andaman Sea. Pinctadaphuketensis sp. nov. is distinguished from other species on both molecular and morphological data. Morphologically, the valves of P.phuketensis are characterized by a slightly developed to undeveloped posterior auricle, a small, narrow slit-like byssal notch, the absence of hinge teeth, and a pale to transparent non-nacreous border, with a few dark brown or red blotches. This new species resembles P.fucata but differs by its smaller size and the absence of hinge teeth. Phylogenetic analyses based on both mitochondrial (COI) and nuclear (18S rDNA, ITS1 and ITS2) genes and species delimitation using COI data strongly support that P.phuketensis is a distinct species, which is closely related to Pinctadaalbina and Pinctadanigra .