Neopleustinae Bousfield & Hendrycks, 1994

Labay, Vjacheslav S., 2021, Review of amphipods of the family Pleustidae Buchholz, 1874 (Crustacea Amphipoda) from the coastal waters of Sakhalin Island (Far East of Russia). I. Subfamily Neopleustinae Bousfield & Hendrycks, 1994, Zootaxa 4974 (2), pp. 267-306 : 268-271

Subfamily Neopleustinae Bousfield & Hendrycks, 1994 ( Bousfield & Hendrycks 1994: 40)

Neopleustinae Bousfield & Hendrycks 1994: 40 .— Hendrycks & Bousfield 2004: 94.

Type genus. Neopleustes Stebbing, 1906: 311 .— Gurjanova 1951: 641.— Gurjanova 1972: 133, 163.— Barnard & Karaman, 1991: 649.— Hendrycks & Bousfield 2004: 94.

Type species. Amphitoe puchella Krøyer, 1845 .

Genera. Hendrycksopleustes gen. nov., Neopleustes Stebbing, 1906 , Shoemakeroides Hendrycks & Bousfield, 2004 .

Diagnosis (from Hendrycks & Bousfield 2004 with additions). Body usually dorsally carinate or mucronate. Urosome 2 occluded or not dorsally. Rostrum medium, extending beyond head lobe, less often short. Antenna 1, peduncular segment 1 not produced anterodistally.

Lower lip usually broad, shallow. Mandibular molar reduced, non-triturative; left lacinia multidentate, right lacinia lacking; raker setae normal, slender; palp large. Maxilla 1, outer plate with 9 apical strong pectinate setae (spine-like setae), inner plate with 1–2 setae. Maxilla 2, inner plate with 1–2 inner margin stout setae. Maxilliped plates short; palp slender (less often medium wide), segment 3 variously produced distally; dactylus slender, pectinate.

Coxal plates 1–4 medium, deepening gradually posteriorly; coxal plates variously with posterodistal cusps; coxal plate 1 not markedly bent forwards; coxal plates 5 and 6 posterolobate. Coxal gills medium, sac-like, lacking on pereopod 7.

Pereopods 1 and 2 (gnathopods) typically subsimilar, weak to srong, or unlike and slightly sexually dimorphic, often powerfully subchelate; propodal palms with triangular median tooth; meral posterodistal tooth lacking or not; carpus usually elongate (less often short), lobe shallow (less often deep).

Pereopods 5–7 subequal in size and form. Epimeral plates 2 and 3 variable, hind corner usually produced. Uropod 1 with distolateral peduncular spine-like seta. Telson keeled proximally, apex rounded.

Distribution. Marine waters of arctic and boreal parts of Northern hemisphere.

Remarks. Subfamily Neopleustinae is closed to Parapleustinae Bousfield & Hendrycks, 1994 but differs in its well developed, often keeled, rostrum, dorsal body processes, large mandibular palp, unspecialized mandibles raker setae; processiferous palp segment 3 of maxilliped, multicuspate coxal plates 1–3, by produced posterior corner of epimeral plates 1 & 3, and midventrally keeled telson ( Bousfield & Hendrycks, 1994, 1995; Hendrycks & Bousfield, 2004).

New genus Hendrycksopleustes has a number of features that bring it closer to the Parapleustinae subfamily: short rostrum, palp medium width, size and shape of pereopods 1 & 2 (gnathopods 1 & 2). Such features as developed dorsal carination, large palp of mandible, form of coxal plate 1, multicuspate coxal plates 1–3, and especially processed hind corner of epimeral plates 2 & 3, make it possible to attribute this genus to the subfamily Neopleustinae . Thus, the genus Hendrycksopleustes gen. nov. occupies an intermediate position between the subfamilies Neopleustinae and Parapleustinae , and tentatively placed as an aberrant form within the Neopleustinae that may be transitional to the Parapleustinae .