Tropicorchestia, Lowry, J. K. & Springthorpe, R. T., 2015

Lowry, J. K. & Springthorpe, R. T., 2015, Coastal Talitridae (Amphipoda: Talitroidea) from north-western Australia to Darwin with a revision of the genus Cochinorchestia Lowry & Peart, 2010, Zootaxa 3985 (2), pp. 151-202 : 190-191

Tropicorchestia gen. nov.

Type species. Tropicorchestia derbyensis gen. nov., sp. nov.

Included species. Marsh-hopper. Tropicorchestia includes two species: T. derbyensis sp. nov.; T. glasbyi sp. nov.

Etymology. The name refers to its geographic location in tropical Australia.

Diagnostic description (based on male). Eyes medium (greater than 1/5 to 1/3 head length). Antenna 1 short, slightly longer than article 4 of antenna 2 peduncle. Antenna 2 peduncular articles slender; peduncular article 3 without ventral process; final flagellar article large, cone-shaped, forming virgula divina. Mandible left lacinia mobilis 4-dentate. Maxilliped palp article 2 distomedial lobe well developed; article 4 reduced, button-shaped. Gnathopod 1 subchelate; posterior margin of merus, carpus and propodus each with lobe covered in palmate setae. Gnathopod 2 subchelate; merus and carpus free; dactylus attenuated distally. Pereopods 3–7 cuspidactylate. Pereopods 5–7 without setae along posterior margin of the dactylus. Pereopods 6–7 not sexually dimorphic, without row of short setae along posterior margin of dactyli. Pleonites 1–3 without dorsal spines. Pleopods all well developed. Epimera without slits just above ventral margins. Uropod 1 rami without apical spear-shaped setae; outer ramus slender; without marginal robust setae. Uropod 3 well developed; ramus shorter than peduncle. Telson entire, with 3–6 robust setae per lobe.

Remarks. The Indo West Pacific genera Tropicorchestia gen. nov., Floresorchestia Bousfield, 1984 and Lanorchestia Miyamoto & Morino, 2010 appear to be very similar. They share nearly all generic-level characters ( Lowry & Bopiah 2012). Floresorchestia differs from Tropicorchestia and Lanorchestia in having epimeral slits. Lanorchestia differs from Floresorchestia and Tropicorchestia in having long first antennae and slightly shortened third pleopods.