Ptilohyale littoralis (Stimpson, 1853)

Brutto, Sabrina Lo & Iaciofano, Davide, 2018, A taxonomic revision helps to clarify differences between the Atlantic invasive Ptilohyalelittoralis and the Mediterranean endemic Parhyaleplumicornis (Crustacea, Amphipoda), ZooKeys 754, pp. 47-62 : 48-50

Ptilohyale littoralis (Stimpson, 1853) Figures 2, 3

Allorchestes littoralis Stimpson, 1853: 49, t 3, fig. 36; Smith 1873: 556; Stebbing 1906: 595; Miner 1950: 462, pl. 148.

Hyale littoralis (Stimpson, 1853) Holmes 1905: 472, pl. 3, fig. 2; Barnard and Karaman 1991: 369.

Hyale prevosti (part) Della Valle, 1893: 519.

Hyale plumulosa (Stimpson, 1853) Bousfield 1973: 155, pl. XLIV.2; Pollock 1998: 241, fig. 15.120.

Plumulohyale plumulosa (Stimpson, 1853) Bousfield 2001: 104.

Ptilohyale littoralis (Stimpson, 1853) Bousfield and Hendrycks 2002: 103; Faasse 2014: 1.

Parhyale explorator Arresti, 1989: 101-115.

Ptilohyale explorator (Arresti, 1989) Bousfield and Hendrycks 2002: 98-99.

Type.

Neotype deposited in Canadian Museum of Nature Collection; voucher number CMNC 2002-0071 ( Bousfield and Hendrycks 2002).

Type locality.

Grand Manan Island (Canada), northern eastern Atlantic coast.

Material examined.

One hundred and twenty-six specimens were collected at the Bay of Arcachon France (43°34'N, 1°14'W), 13October 2015; intertidally, 0 m, on the heavy substrate of the semi-closed beach (MZPA-AMPH-0024).

Description.

Male. 11.4 mm length specimen. Antenna II ventral margins of the 5th peduncular article and first 4-9 flagellar articles (other one or two articles with sparse plumose setae) densely covered with plumose setae (brush setae). Palp of maxilla I with median constriction. Coxal plate I sub-quadrate with distinctive cups; Gnathopod I, basis lacking distinct anterodistal lobe (hydrodynamic lobe). Gnathopod II, carpus lobe present in juvenile male and absent on adult male. Coxal plate V posterior lobe smaller than anterior lobe; Peraeopod V, basis rounded. Peraeopod VII slender, basis rounded. Uropod I, peduncle with one distomedial robust seta; rami subequal with 3-4 robust setae on outer ramous and 1-2 robust setae on inner ramus. Uropod II, rami sub-equal in length. Uropod III, outer ramus with 5-9 apical robust setae. Telson acute. Female. Description based on a 10.6 mm length specimen. Gnathopod I, basis with anterodistal lobe.

Distribution.

Northern, western, and eastern Atlantic coasts; north eastern Pacific coast.

Remarks.

The genus Ptilohyale includes 12 species: P. barbicornis (Hiwatari & Kajihara, 1981); P. barnardi (Chevreux, 1925); P. bisaeta (Kim & Kim, 1991); P. brevicrus Eun et al., 2014; P. crassicornis (Haswell, 1879); P. eburnea (Krapp-Schickel, 1974); P. explorator (Arresti, 1989); P. iole (Barnard, 1970); P. littoralis (Stimpson, 1853); P. plumulosus (Stimpson, 1857); P. ptilocerus (Derzhavin, 1937); P. tristanensis (Macnae, 1953) ( Bousfield and Hendrycks 2002, Eun et al. 2014, Lowry 2010). Of these, the descriptions of three of the species showed characters not ascribable to Ptilohyale sensu Bousfield & Hendrycks (2002). Ptilohyale barnardi (formerly Hyale barnardi ) has brush-setae in antenna II that start at the 4th peduncular article (see Chevreux 1925, Fig. 4A); P. tristanensis (formerly Allorchestes tristanensis ) (see Macnae 1953, Fig. 4B) and P. eburnea (see Krapp-Schickel 1974, Fig. 4C), do not have brush-setae in antenna II. The absence of some diagnostic character states makes us consider Ptilohyale barnardi , P. tristanensis , and P. eburnea as nomina dubia, and we encourage further investigations.