Hendrycksopleustes neimanii Labay 2021
- Dataset
- 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
- Rank
- SPECIES
- Published in
- 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): 267-306, DOI: 10.11646/zootaxa.4974.2.3
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Malacostraca
- order
- Amphipoda
- family
- Pleustidae
- genus
- Hendrycksopleustes
- species
- Hendrycksopleustes neimanii
biology_ecology
Ecology. H. neimanii was found at the depth of 104 m on pebbles sediments with sands and silt. Females with eggs in marsupium were detected in the type locality in August.
description
Description. Female (12 mm). Vital body color unknown; color in alcohol almost colourless, uniformly pale yellow. Body medium, with the carination characters of the genus. Head: shorter than pereonites 1 and 2 combined, without anterodorsal crest, rostrum about 0.1 times as long as peduncular segment 1 of antenna 1; eyes medium, ellipsoid, pigmented; anterior head lobe prominent, truncated, lower margin rounded. Antenna 1: long, nearly 80 % of body length; flagellum bearing 71 articles; peduncle article 1 is 1.25 times as long as the length of article 2, with a few simple setae at the distal corner of posterior margin, without anterodistal process, article 3 is 1 / 3 times the length of article 2; accessory flagellum reduced. Antenna 2: flagellum with 33 articles; peduncle articles 5 slightly shorter than article 4, articles 1 – 3 combined subequal to article 4; article 2 with long posterodistal protrusion, subequal to article 3 length. Labrum: apically bilobate and asymmetrical, without setae. Mandible: molar small, conical, with small conical wart at the axis, and with microsetae, without triturating surface and without a medial molar plumose seta; palp 3 - articulate, article 1 of palp without setae, palp segment 2 with a row of 13 – 16 simple setae (D- 2 setae), palp segment 3 with posterior row of 12 specific plumose D 3 - setae, with group of 4 medium length simple distal E 3 - setae. Labium: inner and outer lobes pubescent. Maxilla 1: inner plate short, rounded distally, with 2 (less often one) plumose setae apically; outer plate subquadrate, apically with 2 rows of 9 strong comb setae; palp 2 - articulate, article 2 with a distal row of thin simple setae at the outer margin and with a subapical row of 5 – 6 simple setae, apical margin of article 2 of with 5 – 7 stout spine-like setae. Maxilla 2: inner plate with one strong plumose seta on the inner margin. Maxilliped: inner plates short, fully cleft, with 5 button spineformes setae (Watling type II. A 3) (Watling 1989) at the truncated apex; outer plate short, subrounded apically, inner margin with submarginal row of simple setae, apex with 3 strong cuspidate setae; palp 4 - articulate, the percentage of total length of the articles of the palp 21 – 23 % (article 1), 25 – 26 % (article 2), 29 % (article 3) and 23 – 25 % (article 4); article 4 (dactylus) slender, slightly curved. Pereon: Pereopod 1 (gnathopod 1): coxa medium depth, with central ventral rounded angle, with 3 small posterodistal cusps; basis linear, with dense row of simple setae along anterior margin and with rare simple setae along posterior margin; merus with a tuft of 2 simple setae at the border of 1 / 2 of posterior margin, distal margin with a dense row of long simple setae; carpus 0.4 times as long as propodus, posterior lobe medium, with a dense row of simple setae along posterior margin; propodus almond-shaped, 2.3 times as long as wide, palmar margin subvertical, with medial tooth at the border of anterior 1 / 6 of palmar margin length, posterior margin indistinct; dactylus curved, 5 / 6 times as long as palmar margin of propodus. Pereopod 2 (gnathopod 2): coxa deep, rounded down, with 2 posterodistal cusps; basis linear, with a row of rare short simple setae anteriorly and with 3 tufts of simple setae in the distal half of posterior margin; merus with an acute tooth at the posterior angle, with a few simple setae at the border of 1 / 2 of posterior margin and with a tuft of simple setae near the base of posterodistal tooth, distal margin truncated; carpus short, 0.4 times as long as propodus, posterior lobe narrow and long, with a dense row of simple setae along posterior margin and with a row of strong cuspidate setae at the posterior part of distal margin; propodus almond-shaped, 2 times as long as wide, palmar margin subvertical, with medial tooth at the border of anterior 1 / 6 of palmar margin length, posterior margin indistinct; dactylus curved, 0.9 times as long as palmar margin of propodus. Pereopod 3: coxa deep, 1.9 times as long as wide, rounded distally, with 1 – 2 posterior teeth; leg slender; basis linear, with rare short setae along anterior and posterior margins; merus 1.5 times as long as carpus, produced slightly forwards along anterior margin of carpus, with 3 – 5 groups of few simple setae along anterior margin and with 5 clusters of few simple setae along posterior margin; propodus long, 1.36 times as long as carpus, with 7 – 8 groups of short strong cuspidate setae along posterior margin; dactylus short, 0.46 times as long as propodus. Pereopod 4: coxa 1.14 times as long as wide, narrowed and rounded distally, with deep excavation posteromarginally; basis to dactylus as for pereopod 3. Pereopod 5: coxa antero- and posterolobate, with rounded ventral front margin, posterior lobe rounded; basis with posterior wing, width 0.68 times length, anterior margin with 7 – 8 groups of 1 – 2 short strong cuspidate setae, posterior margin convex, crenulated; merus slightly produced forwards along posterior margin of carpus, with 5 – 6 cuspidate simple setae along anterior and posterior margins each; the leg from carpus to dactylus missing. Pereopod 6: coxa posterolobate, with oblique front margin, posterior lobe subovate, pulled back and down; basis with posterior wing, width 0.71 – 074 times as length, anterior margin with 7 – 8 groups of 1 – 2 short strong cuspidate setae, posterior margin convex, crenulated; merus slightly produced forwards along posterior margin of carpus, with 5 – 6 cuspidate simple setae along anterior and posterior margins each; carpus 0.69 times as long as merus, with 4 clusters of strong cuspidate setae along anterior margin; propodus linear, 1.22 times as long as carpus; dactylus short, 0.46 times as long as propodus, weakly curved. Pereopod 7: coxa trapezoidal; basis with posterior wing, width 0.7 times as length, anterior margin with 6 – 7 groups of 1 – 2 short strong cuspidate setae, posterior margin convex, crenulated; merus slightly produced forwards along posterior margin of carpus, with 5 – 6 cuspidate simple setae along anterior and posterior margins each; the leg from carpus to dactylus missing. Coxal gills 2 – 6, ovate. Coxal gill 6 smaller than gill 5. Pleon: Epimeral plates: plate 1 rounded triangular, posterior corner with small acute tooth, posterior margin convex, lower margin with 3 strong cuspidate setae along anterior half; plate 2 with acute posteroventral process, ventral margin with 5 spine-like cuspidate setae in anterior 2 / 3, posterior margin convex; plate 3 with long acute posteroventral process, posterior margin convex, ventral margin straight with 5 spine-like setae. Pleopods: normal; inner ramus slightly shorter than outer ramus, coupling basis of inner ramus with 5 – 6 specific stout two-pointed plumose setae along inner margin (6 setae on pleopod 1, 5 setae on pleopods 2 and 3). Uropod 1: peduncle 1.22 times as long as outer ramus; outer ramus the shorter, 0.91 times as long as inner ramus. Uropod 2: inner ramus 1.8 times as long as peduncle, outer ramus the shorter, 0.66 times as long as inner. Uropod 3: inner ramus 3 times as long as peduncle, with acute and non-spinose apex; outer ramus about 0.6 times as long as inner; outer ramus with a row of 5 – 6 small spine-shaped setae along lateral and medial margins each, with acute and non-spinose apex. Telson: (Fig. 6 i) linguiform, apically rounded, length about 1.58 x width, with proximal ventral keel, plumose marginal penicillate setae are absent. Male similar to female.
description
Figures 1 l, 2 h, n, w, ae, 3 h, 4 l, 5 k, 6 – 11, 22
diagnosis
Diagnosis. With the characters of the genus. Body segments strongly carinated dorsally from pereon segment 6 to pleon segment 2, pleon segment 3 with sloping low ridge dorsally. Rostrum short, about 0.1 times as long as peduncular segment 1 of antenna 1, apex acute. Antenna 1, segment 2 of peduncle with small rounded anterodistal process, accessory flagellum minute, scale-like; flagellum with 71 articles, length about 4.6 x peduncle. Lower lip, outer lobes rounded, widely spread. Mandible, molar weak and without a medial molar seta; palp segment 3 subequal to segment 2, segment 2, inner margin setose; segment 1 without setae. Maxilla 1, inner plate with 2 plumose apical setae, rarely with single seta; outer plate with 9 strong pectinate setae (spine-like setae). Maxilliped, inner plate reaching the middle of outer plate basis; outer plate reaching about 0.2 x length of palp segment 2; palp segment 1 subequal in legth to segments 2 and 3 each; dactylus slender, slightly curved and slightly shorter than palp segment 3. Coxal plate 1 – 3 medium; coxal plate 4 much broader, deeply excavated posteroproximally; coxal plates 5 – 6 posterolobate, posteriorly rounded, coxal plate 7 trapezoidal, with rectangular posterodistal angle. Pereopod 1, merus with posterodistal tooth, palmar margin with medial tooth, with a row of 5 strong spineformes setae along posterior part and with 5 transversal clusters of posterodistal strong setae (spines). Pereopod 2, carpal lobe long, merus with posterodistal tooth, palmar margin with medial tooth and with a row of 6 – 7 strong spineformes setae along posterior part and with 5 transversal clusters of posterodistal strong setae (spines). Pereopods 5 – 7, dactylus medium in length, 0.46 – 0.49 times as long as propodus. Epimeral plates 1 – 3, posteroventral corner with acute process. Male similar to female.
distribution
Distribution. The north-east shelf of Sakhalin Island, Sea of Okhotsk (Fig. 22).
etymology
Etymology. Named in honor of famous Russian oceanographer Victor G. Neiman. The name is masculine in gender.
materials_examined
Type material. Holotype female, 12 mm, Х 53857 / Cr- 2402, Sea of Okhotsk, Far East of Russia (53 ° 45 ′ 37.010 N 143 ° 37 ′ 57.186 E, 104 m), pebbles with sands and silt, M. G. Rogotnev, 29 August 2018. Paratypes: 1 male, 8.8 mm, Х 53858 / Cr- 2403, with same data as holotype; 1 female, 13.3 mm, Х 53859 / Cr- 2404, with same data as holotype; 3 females, Х 53860 / Cr- 2405, with same data as holotype. Type locality. The eastern coast of Sakhalin Island, Sea of Okhotsk, Far East of Russia (53 ° 45 ′ 37.010 N 143 ° 37 ′ 57.186 E, 104 m).