Thiorchestia, Lowry & Fanini, 2023

Lowry, James K. & Fanini, Lucia, 2023, The Coastal Talitroid Amphipods of New Caledonia (Amphipoda: Talitroidea), Records of the Australian Museum (Rec. Aust. Mus.) 75 (4), pp. 471-484 : 476-478

Thiorchestia gen. nov.

urn:lsid:zoobank.org:act:8EEBA7EA-0B81-47F2-A9B7-53FC6DF3C8F3

Figs 5–7

Type species. Thiorchestia caledoniana sp. nov., monotypy.

Included species. Thiorchestia caledoniana sp. nov.

Category. Mascupod.

Ecological type. Beach-hopper.

Habitat. Supralittoral zone of sandy beaches.

Etymology. Named for Thio mission, Grande Terre, New Caledonia, the type locality and very first site visited by the authors, their son, and their hosts Bertrand and Paule. Gender feminine.

Size. 9.8 mm.

Diagnosis of male. Head. Antenna 1 slender or slightly incrassate. Gnathopod 1 subchelate; posterior margin of carpus and propodus each with palmate lobe; dactylus cuspidactylate. Pereopod 4 dactylus thickened proximally with notch along posterior margin. Epimera 1–3 without slits. Pleopods well developed. Uropod 1 exopod without marginal robust setae. Uropod 3 subequal in length to peduncle.

Remarks. Thiorchestia is very similar to the Caribbean genus Tethorchestia Bousfield, 1984 . The ramus of uropod 3 is subequal in length to the peduncle in Thiorchestia (shorter in Tethorchestia ). Other differences are considered at species level and the genera are considered convergent.

Distribution. New Caledonia.

Figures

Figure 5. Thiorchestia caledoniana sp. nov., holotype, male, 9.8 mm, AM P.100367; paratype, female, AM P.100368, New Caledonia. Scale: EP, H, MD, U1, UR 0.2 mm; remainder 0.1 mm.

Figure 6. Thiorchestia caledoniana sp. nov., holotype, male, 9.8 mm, AM P.100367; paratype, female, AM P.100368, New Caledonia. Scale: 0.2 mm.

Figure 7. Thiorchestia caledoniana sp. nov., holotype, male, 9.8 mm, AM P.100367, New Caledonia. Scale: P3, P4 0.1 mm; remainder 0.2 mm.