Ptilohyale barbicornis ( Hiwatari & Kajihara, 1981 )

Eun, Ye, Kim, Young-Hyo, Hendrycks, Ed A. & Lee, Kyung-Sook, 2014, The family Hyalidae (Crustacea: Amphipoda: Talitroidea) from Korean waters. 1. Genus Ptilohyale Bousfield & Hendrycks, 2002, Zootaxa 3802 (4), pp. 583-595 : 590-594

Ptilohyale barbicornis ( Hiwatari & Kajihara, 1981)

(Korean Name: Gin-da-ri-hae-jo-sum-i-yeop-sae-u, new) ( Figs 5–7 )

Hyale barbicornis Hiwatari & Kajihara, 1981: 21 , figs 1–3. — Barnard & Karaman, 1991: 369. — Ishimaru, 1994: 67. Allorchestes plumicornis . — Iwasa, 1939: 289, pl. 22, figs 25–26.

Ptilohyale barbicornis . — Bousfield & Hendrycks, 2002: 104, fig. 51.

Material examined. 5 ♂, 13 ♀, Maengseon-ri, Wando Is., 24 may 1998, (C.M. Lee); 1 ♂, Dodun-ri, Seocheongun, 20 June 1998, (C.M. Lee); 1 ♂, Doma-ri, Namhae-gun, 29 June 1998, (Y.H. Kim); 8 ♂, 5 ♀, Chamyeon-ri, Namhae-gun, 29 June 1998, (Y.H. Kim); 1 ♂, Gunlae-ri, Dolsando Is., 30 June 1998, (Y. Eun); 1 ♂, 1 ♀, Gauido Is., Taean-gun, 8 July 2000, (Y.H. Kim); 1 ♂, Hwapo-ri., Goseong-gun, 11 April 2002, (Y.H. Kim); 2 ♂, 1 ♀, Myeongsan-ri, Ulju-gun, 1 May 2002, (Y. Eun); 1 ♂, 1 ♀, Osu-ri, Geoje-si, 7 August 2003, (Y. Eun); 2 ♂, 3 ♀, Jeongdang-ri, Anmyeon-eup, 2 April 2004, (T.S. Park); 1 ♂, 2 ♀, Jagyakdo Is., Incheon-si, 22 May 2004, (Y. Eun); 1 ♂, Myodo Is., Taean-gun, 10 May 2006, (Y.H. Kim); 1 ♂, Myodo Is., Seosan-si, 10 May 2006, (Y.H. Kim); 4 ♂, 3 ♀, Yugsando Is., Yeonggwang-gun, 27 June 2007, (Y.H. Kim); 30 ♂, 30 ♀, Jangsaeongpo-dong, Ulsan-si, 9 January 2008, (Y.H. Kim); 1 ♂, 7 ♀, Yudal-dong, Mokpo-si, 22 August 2008, (Y.H. Kim); 14 ♂, 3 ♀, Geomundo Is., Yeosu-si, 17 April 2009, (Y.H. Kim); 6 ♂, 1 ♀, Seungeon-ri, Anmyeon-eup, Taean-gun, 2 April 2009, (Y.H.

Kim); 6 ♂, 30 ♀, Beophwan-dong, Jejudo Is., 9 June 2011, (Y. Eun); 13 ♂, 24 ♀, Ojo-ri, Jejudo Is., 16 February 2012, (T.S. Park).

Type locality. Kyushu, Hokkaido, Japan.

Description. Male. Body ( Fig. 5 A) about 13.4 mm long, dorsally smooth.

Head. Head rectangular, as wide as long, shorter than pereonites 1–2 combined; eye comparatively large, elliptical. Antenna 1 ( Fig. 5 B) shorter than antenna 2, peduncular articles 1–3 length in ratio of 1: 0.89: 0.89, peduncle slightly longer than half of flagellum, each article with short setae distally; flagellum 12-articulate, articles 4–12 bearing 2 short aesthetascs. Antenna 2 ( Fig. 5 C) shorter than 1/3 of body length, stouter than antenna 1; peduncular article 5 and flagellum articles 1–6 heavily plumose-setose posteriorly; flagellum 12-articulate.

Right mandible ( Fig. 5 D), incisor 7-dentate; lacinia mobilis with 3 serrate teeth; molar strongly triturative, with 1 pappose seta; 2 accessory spines, 2 plumose setae placed between lacinia mobilis and molar process, with pubescence near molar. Maxilla 1 ( Fig. 5 E), inner plate slender, apical margin with 2 plumose setae; outer plate stout, apical margin with 8 serrate spine-teeth (may be missing one); palp uniarticulate, with apical simple seta. Maxilla 2 ( Fig. 5 F), inner plate subequal in length to outer one, with numerous apical setae and mediodistal margin with 1 pectinate seta; outer plate with numerous apical setae. Maxilliped ( Fig.5 G), inner plate slightly extending beyond half of outer plate, with plumose setae medially, 3 conical teeth and 5 plumose setae apically; outer plate subovate, extending to nearly half of palp article 2, with row of simple setae medially, slender setiform teeth and simple setae apically; palp broad, 4-articulate, article 2 broadened, with pinnate setae on inner margin; article 3 broadening distally, apical margins with numerous long setae; article 4 elongate, falcate, inner margin with short setae; unguis slender, acute.

Pereon. Gnathopod 1 ( Fig. 6 A), coxa roundly produced anteroventrally, posterior marginal cusp prominent; basis broadening distally, posterior margin with 2–3 setae; carpus, subtriangular, long, 0.91 x propodus, carpal lobe rounded, carpus and propodus ventral margins with pectinate setae; propodus subrectangular, length 2 x width, palm slightly oblique, defined by two spines; dactylus shorter than half of propodus. Gnathopod 2 ( Fig. 6 B), coxa subquadrate, posterior margin rounded, midposterior marginal cusp prominent; basis with small hydrodynamic lobe anterodistally; carpus short, with elongated carpal lobe; propodus elliptical, longer than 2 x propodus of gnathopod 1, palm long and convex, with rows of long spines and setules, palm defined by two spines, ventral margin with small protuberance behind palmar spines; dactylus falcate, 0.66 x propodus, fitting palm. Pereopod 3 ( Fig. 6 C) slender, coxa similar to coxa 2; basis elongate, posterior margin with row of setae; merus anterior margin with 2 spines; propodus rectangular, posterior margin with 1-1-1-1 spine formula; dactylus very short, medial margin with strong seta; length ratio of articles 2–7 = 1.00: 0.37: 0.73: 0.55: 0.55: 0.20. Pereopod 4 ( Fig. 6 D) similar to pereopod 3. Pereopod 5 ( Fig. 6 E) as long as pereopod 4, length ratio of articles 2–7 = 1.00: 0.26: 0.71: 0.63: 0.71: 0.26; coxa bilobate, much broader than long, anterior lobe slightly larger than posterior lobe; basis subovate, broadly expanded, posterior margin with weak notch and surge seta, anteroproximal margin with 3-4 clusters of spines; merus broadening distally, both margins with spines; carpus, posterior margin lacking spines; propodus rectangular, anterior margin with 2–3 clusters of spines; dactylus short. Pereopod 6 ( Fig. 6 F) longer than pereopod 5, length ratio of articles 2–7 = 1.00: 0.20: 0.68: 0.66: 0.72: 0.16; coxa shallow, bilobate, anterior lobe small, about 1/ 3 x width of posterior lobe; basis ovate, anterior margin with row of spines; posterior margin with weak notch and surge seta; merus-propodus longer than pereopod 5; dactylus similar to pereopod 5. Pereopod 7 ( Fig. 6 G), length ratio of articles 2–7 = 1.00: 0.26: 0.70: 0.70:0.80: 0.20; coxa small, rounded ventrally; basis subovate, extended posteriorly, slightly serrate, anterior margin with row of spines; merus-propodus longer than pereopod 6; dactylus slightly larger than found on pereopod 6.

Pleon. Uropod 1 ( Fig. 7 A) peduncle slightly longer than rami, with 5 dorsolateral, 3 dorsomedial and 1 large distomedial spine, which is about 0.37 x inner ramus; inner ramus with 1 dorsal spine and 3 apical spines; outer ramus with 3 dorsal spines and 2–3 apical spines. Uropod 2 ( Fig. 7 B) about 1/ 3 x uropod 1; peduncle slightly shorter than rami, with 4 dorsolateral and 1 dorsomedial spine; inner ramus subequal in length to outer ramus, with 2 dorsal spines and 4 apical spines; outer ramus with 4 dorsal spines and 3 apical spines. Uropod 3 ( Fig. 7 C) short, uniramous, about 0.25 x uropod 1; peduncle slightly longer than ramus, with 1 dorsal spine; ramus with 7 apical spines, 2 of them long, subequal in length to ramus. Telson ( Fig. 7 D) right lobe lost during dissection, fully bilobate, each lobe with 2 pairs of penicillate setae dorsally.

Female. Body about 7.3 mm long.

Pereon. Gnathopod 1 ( Fig. 7 E), coxa subrectangular, longer than that of male. Gnathopod 2 ( Fig. 7 F), coxa similar in shape but longer than that of male; basis with small hydrodynamic lobe; carpus with lobe; propodus subrectangular, much less robust than male; brood plate subtriangular, very large, apex subacute, length 2/3 times that of basis-propodus combined, with numerous, short marginal brood setae, setae hook-tipped.

Remarks. The following minor morphological differences were found between our material and the Japanese specimens of Hiwatari & Kajihara (1981): 1) coxa 1 produced anteroventrally and slightly broadened (vs. not produced); 2) gnathopods 1–2, ventral margin of propodus with small protuberance behind palmar spines (vs. without protuberance), and 3) pereopods 3–4 more slender. This species is mostly widespread along the west coast to south coast in Korea, mainly among algae and under cobble.

Distribution. Korea, Japan.

Figures

FIGURE 5. Ptilohyale barbicornis (Hiwatari & Kajihara, 1981), male, 13.4 mm, Seodo-ri, Geomundo Is., Korea: A, lateral view; B, antenna 1; C, antenna 2; D, right mandible; E, maxilla 1; F, maxilla 2; G, maxilliped. Scale bars = 1 mm (A – C), 0.5 mm (D – G).

FIGURE 6. Ptilohyale barbicornis (Hiwatari & Kajihara, 1981), male, 13.4 mm, Seodo-ri, Geomundo Is., Korea: A, gnathopod 1; B, gnathopod 2; C, pereopod 3; D, pereopod 4; E, pereopod 5; F, pereopod 6; G, pereopod 7. Scale bars = 0.5 mm (A – G).

FIGURE 7. Ptilohyale barbicornis (Hiwatari & Kajihara, 1981), male, 13.4 mm, Seodo-ri, Geomundo Is., Korea: A, uropod 1; B, uropod 2; C, uropod 3; D, left part of telson; female, 7.3 mm, Seodo-ri, Geomundo Is., Korea: E, gnathopod 1; F, gnathopod 2. Scale bars = 0.5 mm (A – F).