Vinogradovopleustes punctatum Labay 2018, sp. nov.

• Main Author: Labay, Vjacheslav S.
• Format: Text
• Language: unknown
• Published: Zenodo 2018
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Amphipoda; Pleustidae; Vinogradovopleustes; Vinogradovopleustes punctatum; Okhotsk; Pacific; Seta; okhotsk sea; Sakhalin
• Online Access: https://dx.doi.org/10.5281/zenodo.5952065; https://zenodo.org/record/5952065

Vinogradovopleustes punctatum sp. nov. Figures 1–7 Diagnosis . With the characters of the genus. Eyes large, subreniform. Body medium, inflated, carinated middorsally on pereon, pleon and urosome. The whole surface of the body and coxal plates with a large-dotted sculpture. Rostrum elongate, about as long as peduncular segment 1 of antenna 1, apex acute. Antenna 1, segment 2 of peduncle with small anterodistal process, accessory flagellum minute, scale-like. Lower lip, outer lobes rounded not widely spread. Mandible, molar strongly triturative; palp segment 3 subequal to segment 2 in length; segment 2, inner margin weakly setose; segment 1 without setae. Maxilla 1, inner plate with single plumose apical seta; outer plate with 9 strong pectinate setae (spine-like setae). Maxilliped, inner plate reaching base of palp; outer plate reaching about 0.5 x length of palp segment 2; palp segment 2 the longest; segment 3 narrower, slightly broadened medially; dactylus slender, curved, as long as palp segment 3. Coxal plate 1–3 very deep, plate 1 with concave anterior margin; coxa plate 4 much broader, deeply excavated posteroproximally; coxal plates 5–7 posterolobate, posteriorly subquadrate. Pereopod 1, palmar margin without medial tooth, with 3–4 clusters of posterodistal strong setae (spines). Pereopod 2 subequal; carpal lobe short, produced slightly forwards along posterior margin of propodus. Pereopods 5–7, dactylus medium, 0.75 times as long as propodus. Epimeral plate 3, posteroventral corner produced into a large tooth. Type material . Holotype male (?), 8.5 mm, X 47110 Cr 2210, Okhotsk Sea, Far East of Russia (55°00'00''N 142°02'40''E, 130 m), silt and small pebble, V.Iu. Lalov, 27 August 2007. Paratypes: 1 male (?), 8.5 mm, X 47111 Cr 2211, Okhotsk Sea, Far East of Russia (51°20'20''N 144°11'41''E, 170 m), silt and pebble, I.A. Scherbakov, 20 August 2014.; 3 males (?), X 47112 Cr 2212, Okhotsk Sea, Far East of Russia (51°20'04''N 144°13'07''E, 170 m), silt and pebble, I.A. Scherbakov, 20 August 2014.; 2 males (?) X 47113 Cr 2213, Okhotsk Sea, Far East of Russia (51°21'47''N 144°16'53''E, 200 m), silt, 11 September 2016. Type locality . The northern part of Okhotsk Sea, Far East of Russia (55°00'00''N 142°02'40''E, 130 m). Description . Male ? (8.5 mm). Vital body color is unknown; color in alcohol almost colourless, uniformly pale yellow. Body medium, inflated, carinated middorsally on pereon, pleon and urosome 1; urosome segment 2 occluded dorsally. Dorsal carination as in Mesopleustes abyssorum (Stebbing, 1888) (Barnard & Karaman 1991; Bousfield & Hendrycks 1994; Stebbing 1888; Vinogradov 1994): thoracic segments carinate, dorsal carina of each thoracic segment pulled back, pleon segments 1 & 2 with dorsoposterior carina each, pleon segment 3 with pulled up middorsal carina, urosome segment 1 with small pulled up middorsal carina, urosome segment 2 occluded dorsally, urosome segment 3 without dorsal carina (Fig. 2a). The whole surface of the body and coxal plates with a large-pointed sculpture (Figs. 2a, 5f, g). Head (Fig. 2a): slightly shorter than pereonites 1, 2 & 3 combined, rostrum about as long as peduncular segment 1 of antenna 1; eyes large, subreniform; anterior head lobe prominent, acute. Antenna 1 (Fig. 2b): medium length, nearly 40% of body length; flagellum bearing 30 articles; peduncle article 1 1.7 times longer the length of article 2, with a few simple setae at the distal corner of posterior margin, segments 1 & 2 with small anterodistal process each, article 3 0.5 times the length of article 2; accessory flagellum, scale-like. Antenna 2 (Fig. 2c): flagellum with 22 articles; peduncle articles 5 as long as article 4 length, articles 2, 3 combined subequal to article 4 or article 5 each; article 2 with long posterodistal protrusion which subequal to article 3 length. Labrum (Fig. 2d): apical lobes slightly asymmetric. Mandible (Figs. 2e, f, 3a, b): molar strong, columnar, with pavement-type grinding surface; palp 3-articulate, article 1 of palp without setae, palp segment 2 with a rare row of simple setae (D-2 setae), palp segment 3 slightly curved, with posterior row of 5–6 specific plumose D3-setae, with group of 3 plumose distal E3-setae and one simple E-3 seta. Labium (Fig. 3c): inner lobes weak, narrowly sloped; outer lobes rounded at distal margin. Maxilla 1 (Fig. 3d): inner plate ovate, with 1 plumose seta apically; outer plate elongate, apically with 2 rows of 9 pectinate strong setae; palp 2-articulate, apical margin of article 2 with 7 stout spine-like setae and with a row of 7 subapical setae. Maxilla 2 (Fig. 3e): inner plate with one strong plumose seta on the inner margin. Maxilliped (Fig. 3f): inner plates small, fully cleft, short, broad, with short conate setae (Watling type II.A4) (Watling 1989) and with 2 simple setae at the truncated apex; outer plate elongated, rounded apically, inner margin setose, apex with 3 strong setae; palp 4-articulate; article 4 (dactylus) slender, curved. Pereon : Pereopod 1 (gnathopod 1) (Fig. 4a, b, c): coxa deep, with posterior tooth and with 3–5 small posterodistal cusps; basis straight; merus with one simple seta at the border of 2/3 of posterior margin, distal margin with a dense row of numerous setae; carpus 0.6 times as long as propodus, posterior lobe shallow, with 2 groups of simple setae, with posterodistal tuft of numerous simple setae + 2 plumose setae; propodus suboval, 2.2 as long as wide, palmar margin smoothly oblique, 1.6 times as long as posterior margin, without medial tooth, with 3 clusters of posterodistal robust setae associated with a few setae; dactylus shorter than palmar margin of propodus, curved. Pereopod 2 (gnathopod 2) (Fig. 4d, e): coxa deep, with posterior tooth and with 3–5 small posterodistal cusps; basis slightly broadened; merus with a few simple setae at the border of 2/3 of posterior margin, distal margin truncated, with a few simple setae; carpus medium, 0.67 times as long as propodus, carpal lobe short, produced slightly forwards along posterior margin of propodus; propodus suboval, 1.8 as long as wide, with 2 groups of simple setae at the posterior margin, palmar margin smoothly oblique, 1.9 times as long as posterior margin, without medial tooth, with 4 clusters of posterodistal strong setae (spines); dactylus as in pereopod 1. Pereopod 3 (Fig. 5a): coxa deep, 2.2 times as long as wide, rounded anterodistally, with posterior tooth and with 1–3 small posterodistal cusps; leg rather slender; basis linear; merus as long as carpus, produced slightly forwards along anterior margin of carpus; propodus long, 1.15 times as long as carpus; dactylus medium, 0.7–0.8 times as long as propodus. Pereopod 4 (Fig. 5b, c): coxa as long as wide, narrowed and rounded distally, with deep excavation posteromarginally; basis to dactylus as for pereopod 3. Pereopod 5 (Fig. 5d, e): coxa posterolobate, with rounded front margin, posteriorly subquadrate, posterior lobe pulled back and down, with lateral posterior protrusion (stopper); basis linear, without posterior wing; merus produced slightly forwards along posterior margin of carpus, narrow; carpus 0.92 times as long as merus; propodus linear, more narrow and 1.2 times as long as carpus; dactylus medium, 0.72 times as long as propodus, weakly curved, slender. Pereopod 6 (Figs. 5h, 6a): coxa posterolobate, with rounded ventral front margin, posterior lobe pulled back and down, proximally with produced angulated posterior margin; basis with narrow posterior lobe, width 0.43–0.50 times as length, posterior margin straight, with numerous small notches; merus slightly produced forwards along posterior margin of carpus; carpus 0.86 times as long as merus; propodus linear, 1.3 times as long as carpus; dactylus medium, 0.75 times as long as propodus. Pereopod 7 (Fig. 6b, c, d): coxa antero- and posterolobate, anterior lobe small, subquadrate, posterior lobe subquadrate, width subequal to length; basis broadened, with distinct posterior lobe, posterodistal corner rounded, width 0.73–0.75 times as length, posterior margin convex, crenulated; ischium; merus, carpus, propodus and dactylus as in pereopod 6. Coxal gills 2–6. Coxal gill 6 is smaller than gill 5. Pleon : Epimeral plates: (Fig. 6e, f, g) plates 1–2, posterior corners with small tooth each; plate 1 rounded triangular; plate 2, ventral margins convex; plate 3, posteroventral corner produced into a large tooth, ventral margin convex. Pleopods: (Fig. 6h, i, 7a–c) normal; inner ramus slightly shorter than outer ramus, coupling basis of inner ramus with 3–4 specific stout two-pointed plumose setae along inner margin. Uropod 1: (Fig. 7d) peduncle 1.16 times as long as outer ramus, armed with a large robust seta at distal end of outer margin. Uropod 2: (Fig. 7e) inner ramus 1.69 times longer than peduncle, outer ramus 0.79 times as long as inner. Uropod 3: (Fig. 7f) inner ramus 2 times longer than peduncle, with acute and non-spinose apex; outer ramus about 0.73 times as long as inner; outer ramus with a row of 3–4 small spine-shaped setae along lateral and medial margins each, with acute and non-spinose apex. Telson: (Fig. 7g) elongate, linguiform, apically rounded, length about 1.5x width, with median ventral keel, plumose marginal penicillate setae are absent. Female: unknown. Variation . It is not marked. Etymology . Species name punctatum is based on a Latin word punctatum (dotty). The name is masculine in gender. Ecology . Vinogradovopleustes punctatum was found in the depth interval 130–200 m on silt-gravel and silt bottoms. Distribution . The northern part of Okhotsk Sea, the shelf of northern and north-eastern Sakhalin Island (Fig. 1). : Published as part of Labay, Vjacheslav S., 2018, Vinogradovopleustes punctatum, new genus, new species, a pleustid amphipod from the Okhotsk Sea (Crustacea: Amphipoda: Gammaridea: Pleustidae: Pleusymtinae), pp. 159-168 in Zootaxa 4392 (1) on pages 161-167, DOI: 10.11646/zootaxa.4392.1.8, http://zenodo.org/record/1195284 : {"references": ["Stebbing, T. R. R. (1888) Report on the Amphipoda collected by H. M. S. Challenger during the years 1873 - 1876. Report on the Scientific results of the Voyage of H. M. S. Challenger during the years 1873 - 76. Report on the Scientific results of the Voyage of H. M. S. Challenger during the years 1873 - 76, Zoology, 29, 1 - 1737.", "Bousfield, E. L. & Hendrycks, E. A. (1994) A revision of the family Pleustidae (Amphipoda: Gammaridea). Part 1. Systematics and Biogeography of Component Subfamilies. Amphipacifica, 1 (1), 17 - 57.", "Vinogradov, G. M. (1994) Amphipods (Crustacea) from seep fields and nearby common benthic communities of the Northern and Eastern Pacific. Trudy Instituta Okeanologii RAN, 131, 100 - 125. [in Russian]", "Watling, L. (1989) A classification system for crustacean setae based on the homology concept. In: Functional morphology of feeding and grooming in Crustacea. AA Balkema, Rotterdam, pp. 15 - 26."]}