Shoemakeroides Hendrycks & Bousfield, 2004

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 : 301-302

Genus Shoemakeroides Hendrycks & Bousfield, 2004

Shoemakeroides Hendrycks & Bousfield, 2004: 100 .— Dzhurinskyi 2013: 135.

Sympleustes Stebbing, 1899 (part).— Shoemaker 1964: 408.

Stenopleustes G.O. Sars, 1893 (part).— Gurjanova 1972: 160.

Parapleustes Buchholz, 1874 (part).— Karaman & Barnard 1979: 113.— Barnard & Karaman 1991: 649.

Type species. Sympleustes cornigera Shoemaker, 1964: 408 , fig. 9.

Species. Genus Shoemakeroides contains 2 species ( Hendrycks & Bousfield 2004; http://www.marinespecies. org): Shoemakeroides cornigerus ( Shoemaker, 1964) , Shoemakeroides gagarae ( Gurjanova, 1972) .

Diagnosis (from Hendrycks & Bousfield 2004 with additions). Body strong carinate on pereon segments 6, 7 and pleon. Urosome segment 2 occluded dorsally. Rostrum short, without anterodorsal crest. Antenna 1 much longer than antenna 2; peduncular segments 1 and 2 long, without distal process; segment 3 short; accessory flagellum very small, flat. Antenna 2, peduncular segments 4 and 5 subequal in length, with rare setae.

Upper lip slightly notched apically and asymmetrical. Lower lip, outer lobes rounded, angles, widely separated by flat inner lobes. Mandibular molar small, stub-like, finely setulose, triturating surface lacking; left lacinia 8–10-dentate, right lacinia lacking; incisors 7- or 8-dentate; raker setae 8–14, slender; palp strong, segment 3 with 11–14 E setae and with 4 medium length apical setae. Maxilla 1, inner plate with single seta or (rarely) without setae, palp with an apical row of 7 stout conical setae and fine surface setules; proximal segment with 1 or 2 marginal setae. Maxilla 2, inner plate with 1 or 2 subapical inner marginal setae and with rare apical setae. Maxilliped, inner plate broadened, with 4–6 button spineformes setae; outer plate short; palp large, segments subequal in length, segment 3 slightly produced distally, segment 4 slender, slightly cirved.

Coxal plates 1–4 short, slightly increasing in depth and size from 1 to 4. Coxal plate 1 subquadrate with rounded anterodistal and posterodistal angles. Coxal plates 2 and 3 rounded distally. Hind corners of coxae 1–3 each with small cusp. Coxa 5 and 6 posterolobate.

Pereopods 1 and 2 (gnathopods 1 and 2) powerful, dissimilar in form and size, not sexually dimorphic. Pereopod 1 (gnathopod 1), basis with numerose setae along distal half of anterior margin; carpus medium in length, with broad, shellow carpal lobe; propodus strong, palmar margin slightly oblique, with submedial tooth; dactylus slightly curved, as long as palmar margin. Pereopod 2 (gnathopod 2), basis with a row of rare short setae along anterior margin; merus with small postero-distal spine; carpus short, with narrow carpal lobe; propodus strong, inflated, palmar margin oblique, irregular, excavated behind submedial tooth; dactylus strong, slightly curved, as long as palmar margin.

Pereopods 3 and 4 slender, medium long, carpus shorter than merus; dactylus medium in length. Pereopods 5–7, basis slightly broadened, long- rectangular, with rounded posterodistal angle, hind margin minutely serrate; carpus shorter than merus; dactylus medium in length.

Pleon plates 1–3, hind corners produced, acuminate. Uropod 1, peduncle with distolateral spine, peduncle about as long as the inner ramus, outer ramus slightly shorter. Uropod 2, outer ramus distinctly shorter. Uropod 3 slender, outer ramus about 3/5 the length of inner ramus.

Telson linguiform, longer than wide, keeled slightly proximally, without posterodistal notches, lateral margins with few short setae.

Marsupial plates 2 relatively narrow, plates 3 or 4 broad, with medium setae; plate 5 narrow.

Sexual dimorphism is shown in the structure of pereopods 2. In female the palmar margin of propodus with less pronounced excavation than in male.

Distribution. The north Pacific from Gulf of Alaska and Aleutian Islands to Sea of Okhotsk. All species of the genus are found in relatively deep locations in the depth range of 100–1800 m.