Tethorchestia Bousfield 1984
Creators: name: Lowry, J. K.
name: Myers, A. A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Talitridae
Tethorchestia

description: Tethorchestia Bousfield, 1984
Tethorchestia Bousfield, 1984: 204.— LeCroy, 2011: 743, 759.— Wildish & LeCroy, 2014: 557, 558, key.— Lowry & Myers, 2019: 84, 87, figs 38, 39.
“ Tethorchestia ”.— LeCroy, 2011: 743, key, 757 diagnosis.
Type species. Tethorchestia antillensis Bousfield, 1984, original designation.
Included species. Tethorchestia contains 3 species: T. antillensis Bousfield, 1984; T. karukerae Ciavatti, 1989; T. palaeorchestes Bousfield & Poinar, 1995 (fossil, terrestrial, Oligocene).
Ecological type. Beach-hoppers.
Habitat. Living on semi-protected beaches sand beaches.
Diagnostic description (male). Based on Ciavatti (1989) and Wildish & LeCroy (2014).
Head. Antenna 2 peduncular articles slender. Mandible lacinia mobilis 4-cuspidate. Gnathopod 1 sexually dimorphic; subchelate; posterior margin of carpus and propodus each with lobe covered in palmate setae; propodus anterior margin with 4 groups of robust setae, ‘subtriangular’ with well-developed posterodistal lobe, palm transverse; dactylus cuspidactylate. Gnathopod 2 subchelate; propodus palm acute; propodus palm evenly rounded; without palmar sinus; without proximal sinus; without large distal sinus; without proximal spine or thumb defining palm; without large projection near dactylar hinge; dactylus short, strongly curved, longer than palm; recurved distally, attenuated distally or slender, distally acute. Pereopods 3–7 dactyli bicuspidactylate. Pereopod 4 significantly shorter than pereopod 3; carpus significantly shorter than that of pereopod 3; dactylus amplidactylate, thickened proximally with notch midway along posterior margin. Pereopod 6 shorter than pereopod 7, not incrassate; basis moderately expanded; male merus and carpus not expanded. Pereopod 7 not incrassate; basis moderately expanded, or broadly expanded; posterior margin with distinct minute serrations, each with a small seta, posterodistal lobe present, shallow, broadly rounded; carpus unexpanded (subrectangular); subrectangular, or subtriangular (slightly); carpus subequal to propodus; propodus broad; length 3.3–6.5 × width; propodus with large distal tuft of setae. Oostegites (female) setae with simple smooth tips.
Pleon. Pleopods 1–3 all well-developed, or all reduced (slightly). Uropod 1 peduncle distolateral robust seta present; exopod without marginal robust setae; endopod with marginal robust setae in 1 row. Uropod 2 exopod with marginal robust setae in 1 row; endopod with marginal robust setae in 2 rows. Uropod 3 ramus shorter than peduncle. Telson completely cleft or apically incised, with 3–6 robust setae per lobe or with 7–9 robust setae per lobe.
Remarks. Tethorchestia is very similar to Mexorchestia. Tethorchestia has a posterodistal lobe on the basis of pereopod 7 (absent in Mexorchestia) and the oostegites have simple tips in Tethorchestia (oostegites with spatulate tips in Mexorchestia).
Distribution. Mexico and Caribbean Sea (Bousfield 1984, Ciavatti 1989).
description: Published as part of Lowry, J. K. & Myers, A. A., 2022, Platorchestiinae subfam. nov. (Amphipoda, Senticaudata, Talitridae) with the description of three new genera and four new species, pp. 1-53 in Zootaxa 5100 (1) on pages 39-40, DOI: 10.11646/zootaxa.5100.1.1, http://zenodo.org/record/6127681