Protorchestia Bousfield, 1982

Hughes, Lauren E. & Lowry, James K., 2023, Review of New Zealand Coastal Talitroids with description of three new genera (Crustacea, Amphipoda, Senticaudata), Zootaxa 5268 (1), pp. 1-81 : 5

Protorchestia Bousfield, 1982

Protorchestia Bousfield, 1982: 7 .—Lowry & Stoddart, 2003: 275.

Type species. Orchestia nitida Dana, 1852a , original designation.

Included species. Protorchestia includes 4 species: P. campbelliana ( Bousfield, 1964) ; P. ceduna Serejo & Lowry, 2008 ; P. lakei Richardson, 1996 ; and P. nitida ( Dana, 1852a) .

Category. Mascupod ( Lowry & Myers 2019).

Habitat. Marsh-hopper ( Lowry & Myers 2019).

Diagnostic description (male). Eye medium (1/5–1/3 head length). 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. Antenna 2 article 3 without plate or process ventrally; peduncular articles slender. Upper lip epistome without robust setae. Mandible left lacinia mobilis 5-cuspidate. Maxilliped palp broad; article 2 without distomedial lobe; article 4 small, well defined. Gnathopod 1 posterior margin of merus, carpus and propodus each with lobe covered in palmate setae; propodus ‘subtriangular’ with well-developed posterodistal lobe. Gnathopod 2 subchelate; posterior margin of merus, carpus and propodus each without lobe covered in palmate setae; female merus posterodistal lappet absent; propodus palm acute; dactylus not modified distally, blunt, shorter than posterior margin of propodus; female oostegites with curled tips. Pereopods 3–7 simplidactylate. Pereopod 4 dactylus similar to pereopod 3 dactylus, not thickened proximally or notched. Pereopod 5 short, less than 2/3 length of pereopod 6; dactylus long, slender, not inflated. Pereopod 6 subequal in length to pereopod 7; not sexually dimorphic. Pereopod 7 not sexually dimorphic. Epimera 1–3 slits absent. Pleopods 1–3 all well-developed. Uropods 1–2 rami without apical spear-shaped setae. Uropod 1 peduncle distolateral robust seta present (large), male exopod not sexually dimorphic; exopod without marginal robust setae. Uropod 3 ramus subequal in length to peduncle. Telson with apical robust setae only, with 2–6 robust setae per lobe.

Remarks. Protorchestia currently consists of four southern hemisphere species, all of which have either limited known specimens, such as P. campbelliana (1 specimen), P. ceduna (~ 30 specimens), or are from material that is less than 12 mm body size, P. lakei and P. nitida which may imply immature specimens when compared to more well documented species from New Zealand and Australian talitrid species (Table 1).

Distribution. Australia. Tasmania (Richardson 1996); South Australia ( Serejo & Lowry 2008). Chile ( Dana 1852a). New Zealand. Campbell Island ( Bousfield 1964).