Terepeltopes dolichorhunia Hirayama 1983
Creators: name: Ariyama, Hiroyuki
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Cyproideidae
Terepeltopes
Terepeltopes dolichorhunia

description: Terepeltopes dolichorhunia Hirayama, 1983
[Japanese name: Tsubasa-biyadaruyokoebi] (Figs 21–25)
Terepeltopes dolichorhunia Hirayama, 1983: 118, figs 26–28 (type locality: Shijiki Bay, Hirado City, Nagasaki Prefecture, Japan).— Barnard & Karaman, 1991: 259.— Ishimaru, 1994: 53.— Jung et al., 2015: 127, figs 1–3.
Material examined. Two ovigerous females and 1 female (OMNH-Ar-9966–9968), 3.1, 3.1, 3.0 mm, Koganezakipark beach, Nishi-izu Town, Shizuoka Prefecture, 34°50'37"N, 138°45'49"E, 10–12 m in depth, sandy bottom, using SCUBA, 17 July 2012, coll. M. Fujii; 1 male? (OMNH-Ar-9969), 2.1 mm, mouth of Moroiso Bay, Misaki City, Kanagawa Prefecture, 35°09'25"N, 139°36'37"E, 4.5–5.0 m in depth, sandy bottom, using dredge, 14 July 2014, coll. H. Kohtsuka; 1 ovigerous female (OMNH-Ar-9970), 3.5 mm, Kodomari Bay, Yashiro Island, Suooshima Town, Yamaguchi Prefecture, 1 m in depth, sandy bottom, using sled net, 11 December 1997, coll. Y. Hanamura.
Description. Female [based on 3.1 mm (OMNH-Ar-9966), and 3.1 mm (OMNH-Ar-9967) for maxilla 1 and coxa 1]. Body (Fig. 21) roundish mountain-shaped; head longer than pereonite 1, anterior margin with ventrallyoriented spine, eyes medium-sized; pereonites and pleonites smooth, with pereonites 3–5 (especially pereonite 4) enlarged; coxa 5 barely reaching posteroventral corner of pereonite 5; pleonites without lateral ridge, pleonal epimera 1–3 rounded each on posteroventral corner, all ventral margins bare; urosomite 1 long, dorsal margin with large keel projected dorsally, tip of keel pointed, urosomites 2–3 very short.
Antenna 1 (Fig. 22 A) short, with ratio of lengths of peduncular articles 1–3 1:0.6:0.4; accessory flagellum absent; primary flagellum with 4 articles (articles 2–3 very short), with many aesthetascs. Antenna 2 (Fig. 22 B) short; peduncular article 3 short and articles 4–5 relatively long; flagellum with 4 articles, tip bearing a few long setae.
Upper lip (Fig. 22 C) incised, asymmetrical. Mandible (Fig. 22 D, D1, E, E1), incisor bearing 10 cusps in left and 8 cusps in right, left lacinia mobilis fan-shaped, distal margin 8-dentated, right lacinia mobilis small, cylindrical, number of accessory blades 9 in left and 8 in right; molar developed; palp article length ratio 1:1.6: 2.2 in left, all articles without setae. Lower lip (Fig. 22 F), inner lobes indistinct; outer lobes projected anteriorly, covered with fine setae, each medial margin bearing small projection, mandibular processes vestigial. Maxilla 1 (Fig. 22 G, G1), inner plate longish triangular, without distal setae; distal end of outer plate with 8 robust and 8 normal setae; distal end of palp bearing 3 blunt robust setae. Maxilla 2 (Fig. 22 H) slender; inner plate shorter than outer, terminal ends of inner and outer plates with 1 inverted-triangular robust setae and 1 blunt robust setae, respectively. Maxilliped (Fig. 22 I, I1), inner plate truncate, dorsodistal part bearing 4 small robust setae; outer plate small, distal end with 1 robust seta, mediodistal margin with 2 small robust setae; palp consisting of 4 articles, mediodistal corner with 3 belt-shaped setae, article 3 narrow, with large apicodistal process, medial margin bearing 2 belt-shaped setae, article 4 slender.
Gnathopod 1 (Fig. 23 A, A1), coxa small, distorted pentagonal, ventral margin with 2 setae; basis straight, anterior margin setose; merus short; carpus long, posterior margin with 2 setae, posterodistal projection bearing several distal setae; propodus longer than carpus, with 1 anterior and 2 posterodistal setae; dactylus long, posterior margin with 1 denticle. Gnathopod 2 (Fig. 23 B) same length as gnathopod 1; coxa small, roundish rectangular, anterodistal corner with 1 seta; basis stout, slightly widened distally, anterior margin setose; merus short, distal end with several setae; carpus long, posterior margin with 1 seta, posterodistal projection bearing several distal setae; propodus shorter than carpus, slightly widened distally, posterodistal corner with small spine and 2 setae; dactylus short, posterior margin with 1 denticle.
Pereopod 3 (Fig. 23 C), coxa wide, semicircular, anterior margin rounded, posterior margin slightly concave, posteroproximal corner with small projection; basis long, slender, anterior margin heavily setose. Pereopod 4 (Fig. 23 D), coxa extremely wide, middle–ventral part swollen posteriorly, anterior margin slightly convex; basis long, slender, anterior margin heavily setose. Pereopod 5 (Fig. 23 E), coxa relatively large, parallelogramatic, posterodistal corner roundly projected; basis narrow, anterior and posterior margins bearing sparse setae; posterodistal corner of merus projected. Pereopod 6 (Fig. 23 F), coxa semiquadrate, produced posteroventrally; basis almost straight, anterior and posterior margins with several setae; posterodistal corner of merus projected. Pereopod 7 (Fig. 23 G) shorter than pereopod 5; coxa roundish pentagonal; basis wide, roundly swollen; merus projected posterodistally.
Pleopods (Fig. 24 A–C), pleopod 3 shortest; peduncles of pleopods 1–2 bare, pleopod 3 with 2 short setae; inner rami with 7 articles and outer rami with 8 articles in all. Uropods (Fig. 24 D–F) slender, peduncle and both rami without robust setae, but bearing minute denticles; peduncle of uropod 1 long, both rami 93% length of peduncle; uropod 2 84% as long as uropod 1, inner ramus longer than outer, about 1.1 times as long as peduncle, outer ramus about 0.9 times length of peduncle; uropod 3 short, about 0.6 times as long as uropod 1, peduncle short, inner ramus longer than outer, inner and outer rami about 1.4 and 0.8 times as long as peduncle, respectively. Telson (Fig. 24 F) roundish triangular, breadth 55% of length, dorsal surface and margins bare.
Small individuals (male?) [based on 2.1 mm (OMNH-Ar-9969)]. Gnathopods almost similar to female except for oostegite on coxa 2.
Coloration in fixed specimen (Fig. 25). Head and antennae brown, eyes red; pereonites and pleonites light brown with brown mottles; coxa 3 wholly brown, coxa 4 brown with white anteroventral and posteroventral marks, coxa 5 brown.
Remarks. Morphological characters of these specimens almost agree with the description and figures of Hirayama (1983). However, the numbers of setae on the maxilla 1 are different (the original description in parentheses): the inner plate without setae (with 1 seta), the outer plate with 8 robust setae and 8 normal setae (with 13 setae and 6 teeth), and the palp with 3 robust setae (with 4 teeth). In the maxilla 1 of Korean specimens, the outer plate has 9 stout and 4 minute spines and the palp has 4 setae (Jung et al. 2015).
Distribution. Japan: Misaki City in Kanagawa Prefecture, Nishi-izu Town in Shizuoka Prefecture, Suooshima Town in Yamaguchi Prefecture (present study, Fig. 1); Shijiki Bay in Nagasaki Prefecture (Hirayama 1983). Korea: from Gyeongsangnam-do to Incheon-si (Jung et al. 2015).
Habitat. Sandy bottom, 1–12 m in depth (present study). This species occurs together with Cyproidea liodactyla in Nishi-izu Town.
description: Published as part of Ariyama, Hiroyuki, 2016, Five species of the family Cyproideidae (Crustacea: Amphipoda) from Japan, with the description of a new genus and two new species, pp. 301-331 in Zootaxa 4097 (3) on pages 325-330, DOI: 10.11646/zootaxa.4097.3.1, http://zenodo.org/record/263937