Platorchestia Bousfield, 1982

Suklom, Anotai, Keetapithchayakul, Tosaphol Saetung, Rahim, Azman Abdul & Wongkamhaeng, Koraon, 2025, Two new species of riparian hoppers (Amphipoda, Talitridae) from Trat and Samut Prakan provinces, Thailand, ZooKeys 1234, pp. 369-396 : 369-396

Platorchestia Bousfield, 1982

Platorchestia Bousfield, 1982: 26; Jo 1988: 160; Richardson 1991: 186; Morino and Ortal 1995: 825; Miyamoto and Morino 2004: 68; Myers and Lowry 2023: 486.

Type species.

Platorchestia platensis ( Krøyer, 1845) , original designation.

Diagnostic description.

(modified from Myers and Lowry 2023) Antenna 1 short, not longer than article 4 of antenna 2 peduncle. Antenna 2 peduncular article 3 without ventral plate; articles 4 and 5 occasionally incrassate in males. Maxilliped palp article 2 with distomedial lobe; article 4 reduced, button-shaped. Gnathopod 1 sexually dimorphic; subchelate; posterior margin of carpus and propodus each lobe covered in palmate setae; dactylus cuspidactylate. Gnathopod 2 subchelate in male, mitten-shaped in female; basis narrow or slightly expanded; propodus palm posterodistal corner without protuberance. Pereopods 3–7 cuspidactylate. Pereopod 7 occasionally incrassate in male. Uropod 1 outer ramus without marginal robust setae. Telson with apical and marginal robust setae.

Species composition.

Platorchestia contains 13 species: P. ano Lowry & Bopiah, 2013 ; P. aquaticus sp. nov.; P. crassicornis ( Costa, 1867) ; P. exter Myers & Lowry, 2023 ; P. griffithsi Myers & Lowry, 2023 ; P. munmui Jo, 1988 ; P. negevensis Myers & Lowry, 2023 ; P. oliveirae Myers & Lowry, 2023 ; P. pachypus ( Derzhavin, 1937) ; P. pacifica Miyamoto & Morino, 2004 ; P. paraplatensis Serejo & Lowry, 2008 ; P. platensis ( Krøyer, 1845) ; P. smithi Lowry, 2012 .

Remarks.

Miyamoto and Morino (2004) established three groups of Platorchestia based on the presence or absence of sexual dimorphism. Lowry and Myers (2022) established the new subfamily Platorchestiinae , which accommodates 15 genera, including Platorchestia . The Platorchestia sensu stricto is equivalent to Group 1 of Miyamoto (antenna 2 and pereopods 6 and 7 are strongly sexually dimorphic and represented by supralittoral species). Subsequently, Myers and Lowry (2023) described three new Platorchestia species and provided the diagnostic characteristics as antenna 2 sexually dimorphic by articles 4 and 5, which are generally incrassate in males and pereopod 7 often incrassate in male articles 5–7. The combination of antenna 2 and pereopod 7 incrassate was classified into Group 1 and Group 2 by Miyamoto and Morino (2004).