Type genus. Talitrus Bosc, 1802.
Included genera (64). Africorchestia Lowry & Coleman, 2011; Americorchestia Bousfield, 1991; Amphiatlantica Lowry & Myers, 2019a; Asiaorchestia Lowry & Myers, 2019a; Atlantorchestoidea Serejo, 2004; Australorchestia Serejo & Lowry, 2008; Austropacifica Lowry & Springthorpe, 2019a; Bellorchestia Serejo & Lowry, 2008; Britorchestia Lowry & Bopiah, 2012; Bulychevia Lowry & Myers, 2019a; Canariorchestia Lowry & Myers, 2019a; Capeorchestia Lowry & Baldanzi, 2016; Cariborchestia Smith, 1998; Chelorchestia Bousfield, 1984; Chevreuxiana Lowry & Myers, 2019a; Chroestia Marsden & Fenwick, 1984; Cryptorchestia Lowry & Fanini. 2013; Dallwitzia Lowry & Myers, 2019a; Defeo Lowry & Myers, 2019a; Derzhavinia Lowry & Myers, 2019a; Deshayesorchestia Ruffo, 2004; Ditmorchestia Morino & Miyamoto, 2015d; Ezotinorchestia Morino & Miyamoto, 2016a; Floresorchestia Bousfield, 1984; Galaporchestia Lowry & Myers, 2019a; Gazia Lowry & Springthorpe, 2019; Hermesorchestia Hughes & Lowry, 2017; Houlia Lowry & Myers, 2019a; Indiorchestia Lowry & Myers, 2019a; Kaalorchestia Lowry & Myers, 2019a; Kokuborchestia Morino & Miyamoto, 2015c; Laniporchestia Lowry & Myers, 2019a; Lanorchestia Miyamoto & Morino, 2010; Lowryella Morino & Miyamoto, 2016b; Macarorchestia Stock, 1989 a; Megalorchestia Brandt, 1851; Mexorchestia Wildish & LeCroy, 2014; Minamitalitrus White, Lowry & Morino, 2013; Morinoia Lowry & Myers, 2019a; Nipponorchestia Morino & Miyamoto, 2015a; Notorchestia Serejo & Lowry, 2008; Opunorchestia Lowry & Myers, 2019a; Orchestia Leach, 1814; Orchestoidea Nicolet, 1849; Paciforchestia Bousfield, 1982; Palmorchestia Stock & Martin, 1988; Pickorchestia Lowry & Myers, 2019a; Persianorchestia Momtazi, Lowry & Hekmatara, 2017; Platorchestia Bousfield, 1982; Pyatakovestia Morino & Miyamoto, 2015b; Pseudorchestoidea Bousfield, 1982; Sardorchestia Ruffo in Tafani et al., 2004; Sinorchestia Miyamoto & Morino, 1999; Speziorchestia Lowry & Myers, 2019a; Talitrus Bosc, 1802; Talorchestia Dana, 1853; Tethorchestia Bousfield, 1984; Tongorchestia Lowry & Bopiah, 2013; Transorchestia Bousfield, 1982; Traskorchestia Bousfield, 1982; Trinorchestia Bousfield, 1982; Tropicorchestia Lowry & Springthorpe, 2015; Vallorchestia Lowry, 2012; Vietorchestia Dang & Le, 2011.
Category. Mascupods, femipods and semi-mascupods.
Ecological type. Marsh-hoppers, beach-hoppers, sand-hoppers, driftwood-hoppers, cave-hoppers, moss-hoppers, forest-hoppers, riparian-hoppers, field-hoppers.
Distribution. Australia and Papua New Guinea; New Zealand; New Caledonia; India; South Africa, West Africa, East Africa and the Red Sea; Western Indian Ocean and the Persian Gulf; Indonesia and Malaysia; the Caribbean, Pacific North America and the Pacific Plate; Japan and Russia; Taiwan; China; Pacific South and Central America; Atlantic South America; Western North Atlantic; East Atlantic and Mediterranean Sea.
Diagnostic description. Antenna 1 long, reaching to at least midpoint of peduncular article 5 of antenna 2, or short, not reaching midpoint of peduncular article 5 of antenna 2. Maxilliped palp article 2 with distomedial lobe; article 4 reduced, button-shaped or fused to article 3. Gnathopod 1 mainly posterior margin of carpus and propodus each with palmate lobes or posterior margin of merus, carpus and propodus each with palmate lobes or posterior margin, much less frequently with or without palmate lobes on merus, carpus and propodus or only on carpus or propodus; propodus subrectangular or ‘subtriangular’ with well-developed posterodistal lobe or subrectangular, tapering distally. Gnathopod 2 subchelate or mitten-shaped; dactylus with or without posteroproximal projection. Pereopods 3–7 cuspidactylate or pereopods 3, 4 cuspidactylate, 5–7 simplidactylate or homosimplidactylate. Pereopod 4 dactylus amplidactylate or homobasidactylate. Pereopod 5 dactylus not inflated. Pereopod 6 subequal in length, shorter or longer than pereopod 7. Pereopod 7 sexually dimorphic (basis, merus and carpus expanded or merus and carpus expanded) or not sexually dimorphic. Epimera 1–3 slits present or absent. Uropods 1–2 rami with or without apical spear-shaped setae. Uropod 1 male exopod not sexually dimorphic; exopod with marginal robust setae in one row or with marginal robust setae in two rows or without marginal robust setae. Uropod 3 ramus subequal in length, longer or shorter than peduncle. Telson with apical and marginal robust setae, with 2 to at least 10 robust setae per lobe.
Remarks. According to Bousfield (1984) Chelorchestia and Galaporchestia have pereopods 3 to 7 simplidactylate. Either this designation is incorrect or these two genera are convergently homosimplidactylate and homobasidactylate.
Houlia is based on a female only. It has an unusual pereopod dactylation formula. Pereopods 3 and 4 are simplidactylate and 5–7 are cuspidactylate so it cannot be in the Protorchestoidae in which epifamily all the pereopods are simplidactylate. Based on non-sexually dimorphic characters Houlia is placed in the Talitrinae.
Platorchestia is the widest ranging talitrid amphipod genus in the northern hemisphere from the North Atlantic to Japan in the north-western Pacific. It is found throughout the southern hemisphere on many isolated islands.