Description of a new species of Guyanacaris Sakai, 2011 (Decapoda: Axiidea: Axiidae) from the South China Sea

A new species of axiidean shrimp, Guyanacaris xinzhengi, , is described and illustrated based on a single specimen recently collected from Beibu Gulf, in the South China Sea, at a depth of 250-300 m. The new species is characterised by: the rostrum reaching midlength of antennular peduncle article 2; the eyestalk reaching the tip of the rostrum; the dactylus of the major cheliped being curved, shorter than the palm, with its upper margin unarmed and its opposable margin with one prominent bifid proximal tooth and one triangular notch; the dactylus of the minor cheliped being unarmed on upper margin, and the opposing fixed finger with an additional row of teeth on the mesial surface; the telson with three pairs of posterolateral teeth and a median tooth; and the uropodal exopod with its dorsal surface armed with a longitudinal row of three teeth. The morphological differences between the new species and other congeners are discussed and a key to the six species of Guyanacaris is provided. DNA barcoding sequences (16S rRNA and COI) have been submitted to GenBank.