Ptilohyale brevicrus Eun, Kim, Hendrycks & Lee, 2014, sp. nov.
Creators: name: Eun, Ye
name: Kim, Young-Hyo
name: Hendrycks, Ed A.
name: Lee, Kyung-Sook
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Hyalidae
Ptilohyale
Ptilohyale brevicrus

description: Ptilohyale brevicrus sp. nov.
(Korean Name: Jjal-beun-da-ri-hae-jo-sum-i-yeop-sae-u, new) (Figs 2–4)
Type material. Holotype. Adult male, 5.9 mm, dissected on 7 slides, (NIBRIV0000268857), Yeochamongdol sand beach, Geojedo Is., Korea (34°42’49.3”N, 128°37’35.3”E), 7 August 2003, (Y.H. Kim) Paratype, 9 ♂ and 4 ♀, (NIBRIV0000268858) other data same as holotype.
Etymology. The species name is derived from the Latin brevi (=short) and crus (=leg) with reference to the short form of the pereopods.
Diagnosis. Body small, smooth; gnathopod 1, propodus broadening distally; gnathopod 2, carpal lobe lacking, propodus medium-sized, shorter than basis; pereopods 3–7, basis less than 2 x ischium–dactylus; uropods 1–2, rami shorter than peduncle, distomedial peduncular spine very strong, about 0.5 x inner ramus.
Description. Holotype, adult male.
Body (Fig. 2 A) small, about 5.9 mm long, dorsally smooth.
Head. Head about 0.8 x as long as pereonites 1–2 combined, half concealed by coxa 1; eye medium, weakly reniform. Antenna 1 (Fig. 2 B) about 0.6 x as long as antenna 2, peduncular articles 1–3 length in ratio of 1: 0.76: 0.57, with distal setae; flagellum 10-articulate, each article bearing 2 short aesthetascs and short setae distally. Antenna 2 (Fig. 2 C) short, 0.25 x body length, stouter than antenna 1, peduncular article 5 and flagellum articles 1–6 posteriorly strongly plumose-setose; flagellum 13-articulate. Upper lip (Fig. 2 D) covered with patch of pubescence apically. Lower lip (Fig. 2 E) inner lobe indistinct; outer lobe densely pubescent. Left mandible (Fig. 2 F) incisor 7-dentate; lacinia mobilis 6-dentate; molar strongly triturative, with 1 pappose seta; 3 accessory spines, 4 setae and several setules placed between lacinia mobilis and molar, with pubescence near molar. Right mandible (Fig. 2 G) incisor 6-dentate plus 4 small teeth; lacinia mobilis with 2 serrate teeth; molar strongly triturative, with 1 pappose seta longer than that of left molar; 2 spines, 3 setae and several setules placed between lacinia mobilis and molar, with pubescence near molar. Maxilla 1 (Fig. 2 H) inner plate slender, rectangular, shorter than outer plate, apical margin with 2 unequal plumose setae; outer plate stout, apical margin with 9 serrate spine-teeth; palp uniarticulate, pubescent, extending past distal end of outer plate, apical margin with 1 seta. Maxilla 2 (Fig. 2 I) inner plate with numerous apical setae and mediodistal margin with 1 pectinate seta; outer plate slightly longer than inner one, with numerous apical setae.
Pereon. Gnathopod 1 (Fig. 3 A) coxa broadening distally, with weak posterior marginal cusp; basis lacking hydrodynamic lobe anterodistally; carpal lobe broad, with 12 comb setae posteriorly; propodus gradually broadened distally, with row of setae on ventral margin, palm nearly transverse, with short setae, defined by two spines; dactylus falcate, fitting palm. Gnathopod 2 (Fig. 3 B) coxa subquadrate, posterior margin rounded, midposterior cusp prominent; basis subrectangular, broadening distally, with small hydrodynamic lobe; ischium lacking hydrodynamic lobe; carpal lobe vestigial; propodus about 2 x length of gnathopod 1, palm oblique and convex, slightly longer than posterior margin of propodus, with rows of long spines and setules, corner defined by 2 spines distally; dactylus strong, fitting palm. Pereopod 3 (Fig. 3 C) coxa length about 1.1 x width, posterior marginal cusp prominent; basis with 3 setae on posterior and anterodistal margin; merus slightly swollen midanteriorly, anterior margin with 2 spines; propodus short, posterior margin with a spine, posterodistal margin with setae and 1 spine; dactylus short and stout, anterior margin with strong seta; length ratio of articles 2–7 = 1.00: 0.36: 0.60: 0.36: 0.36: 0.15. Pereopod 4 (Fig. 3 D) similar to pereopod 3, but merus anterior margin with 1 spine. Pereopod 5 (Fig. 3 E) shorter than pereopod 6, length ratio of articles 2–7 = 1.00: 0.24: 0.50: 0.43: 0.48: 0.17; coxa bilobate, much broader than long, concave ventrally, anterior lobe length 0.53 x width and posterior lobe length 0.46 x width; basis ovate, posterior margin slightly crenulate, with slight notch and surge seta, with row of spines anteriorly; merus short, broadened distally, anterior margin with 2 clusters of 2 spines, posterior margin with 2 spines, distal margins with clusters of spines; carpus broadened distally, anterior margin with 2 spines, posterior margin lacking spines, distal margins with clusters of spines; propodus, anterior margin with 2 clusters of 2 spines, posterior margin lacking spines, anterodistal margin with 2 spines; dactylus very short, about 0.25 x propodus. Pereopod 6 (Fig. 3 F) length ratio of articles 2–7 = 1.00: 0.23: 0.58: 0.42: 0.42: 0.12; coxa small, bilobate, concave ventrally, anterior lobe very small, 1/ 3 x posterior lobe; basis ovate, posterior margin slightly crenulate, with slight notch and surge seta, length 1.2 x width, anterior margin with row of spines; merus broadened posteriorly, margin with 4 spines, anterior margin with 2 clusters of 2 spines, distal margins with clusters of spines; carpus gradually broadened distally, anterior margin with 1 cluster of 2 spines, posterior margin lacking spines, posterodistal margin with strong cluster of spines; propodus and dactylus similar to that of pereopod 5. Pereopod 7 (Fig. 3 G) slightly longer than pereopod 6, length ratio of articles 2–7 = 1.00: 0.27: 0.62: 0.48: 0.52: 0.14; coxa rounded ventrally, length 0.5 x width; basis ovate, posterior margin slighltly serrate, posteroventral corner expanded, anterodistal margin with 3 spine clusters; merus subrectangular, anterior margin with 2 clusters of 2 spines and posterior margin with 4 spines, distal margins with spines; carpus-dactylus similar to pereopod 6.
Pleon. Uropod 1 (Fig. 4 A) peduncle length 1.6 x outer ramus, with 3 dorsolateral, 1 distolateral, 4 dorsomedial and 1 distomedial large spine, which is about 0.5 x length of inner ramus; inner ramus subequal in length to outer ramus, with 1 dorsal spine and 4 apical spines; outer ramus with 2 dorsal spines and 3 apical spines, length of rami about 0.62 x peduncle. Uropod 2 (Fig. 4 B) length 0.6 x uropod 1; peduncle length 1.4 x outer ramus, with 2 dorsolateral, 1 distolateral and 1 dorsomedial spine; inner ramus slightly longer than outer ramus, with 2 strong dorsal spines and 4 apical spines; outer ramus with 1 dorsal spine, 1 subapical spine and 3 apical spines, rami short, length about 0.66–0.71 x peduncle. Uropod 3 (Fig. 4 C) short, uniramous, length 0.2 x uropod 1; peduncle slightly longer than ramus, with 1 dorsal spine; ramus, apex blunt with 5 short, apical spines. Telson (Fig. 4 D) fully bilobate; each lobe with a pair of penicillate setae dorsally and a pair of simple setae distally.
Female, paratype. Body small, about 5.3 mm long.
Pereon. Gnathopod 1 (Fig. 4 E) coxa similar to that of male, but slightly longer; basis slightly narrower; carpal lobe not as broadly rounded; propodus slender, length 2 x width. Gnathopod 2 (Fig. 4 F), coxa very large, more than half length of basis-dactylus combined, length 1.4 x width; basis anterodistal corner somewhat rounded; carpus with lobe; propodus much less robust than male, in form similar to male gnathopod 1; brood plate subtriangular, apex narrowed, subacute, very large, with short and hooked brood setae marginally.
Remarks. Ptilohyale brevicrus is distinguished from P. barbicornis (characters of P. barbicornis in brackets) by the following features: 1) body small, 6–7 mm at maturity (vs. large, more than 10 mm at maturity); 2) pereopods 3–7, basis less than 2 x ischium–dactylus combined (vs. more than 2 x); 3) coxa 2 subequal to propodus (vs. shorter than propodus); 4) uropods 1–3 rami short, much shorter than peduncle (vs. elongate, subequal or longer than peduncle); 5) uropod 1 distomedial spine stronger, length 0.5 x inner ramus (vs. 0.37 x inner ramus); 6) uropod 3, apical spines of ramus much shorter than ramus (vs. subequal to ramus). P. b rev i cr u s is found in a slightly different habitat. Both are found in the intertidal zone, but P. b rev i cr u s prefers cobble and sand, while P. barbicornis prefers algae and cobble.
Distribution. Korea (Geojedo Is.).
description: Published as part of 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, pp. 583-595 in Zootaxa 3802 (4) on pages 586-589, DOI: 10.11646/zootaxa.3802.4.8, http://zenodo.org/record/228425