Uroptychus spinirostris
Creators: name: Baba, Keiji
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Chirostylidae
Uroptychus
Uroptychus spinirostris

description: Uroptychus spinirostris (Ahyong & Poore, 2004)
Figures 245, 306E
Gastroptychus spinirostris Ahyong & Poore, 2004: 9, fig. 1.
Uroptychus spinirostris – Baba 2005: 231 (synonymy and key). — Baba et al. 2008: 43, fig. 1H. — Poore et al. 2011: 330, pl. 8, fig. C. — McCallum & Poore 2013: 165, figs 8, 12A.
TYPE MATERIAL — Holotype: Australia, NE of Tweed Heads, Queensland, 28°02-05’S, 153°57’E, 364 m, male (AM P31418). [not examined].
MATERIAL EXAMINED — Indonesia, Kai Islands.KARUBAR Stn CP16, 05°17’S, 132°50’E, 315-349 m, 24.X.1991, 1 ♂ 7.4 mm, 1 ♀ 7.2 mm (MNHN- IU-2014-16957). Vanuatu. BOA 0 Stn CP2330, 15°44.4’S, 167°01.83’E, 295-890 m, 18.XI.2004, 1 ov. ♀ 7.5 mm (MNHN-IU-2014-16958). MUSORSTOM 8 Stn CP1083, 15°51.91’S, 167°19.42’E, 397-439 m, 5.X.1994, 1 ♂ 3.6 mm (MNHN-IU-2014-16959). Vanuatu, Monts Gemini. GEMINI Stn DW51, 20°58’S, 170°04’E, 450- 360 m, 04.VII.1989, 1 ♂ 7.0 mm (MNHN-IU-2014-16960). New Caledonia. BATHUS 4 Stn DW903, 18°59.93’S, 163°13.55’E, 386-400 m, 4.VIII.1994, 1 ♂ 13.2 mm (MNHN-IU-2014-16961). New Caledonia, Norfolk Ridge. BATHUS 3 Stn CP812, 23°43’S, 168°16’E, 391-440 m, 28.XI.1993, 3 ov. ♀ 10.3 -11.7 mm, 1 ♀ 11.3 mm (MNHN-IU-2014-16962). NORFOLK 2 Stn CP2111, 23°48.56’ S, 168°16.78’E, 500-1074 m, 31.X.2003, 1 ♀ 6.0 mm (MNHN-IU-2014-16963).
DISTRIBUTION„ Queensland and western Australia, and now New Caledonia, the Norfolk Ridge, Monts Gemini, Vanuatu and the Kai Islands (Indonesia); 315-1074 m.
SIZE„ Males, 3.6-13.2 mm; females, 6.0- 11.7 mm; ovigerous females from 7.5 mm.
DIAGNOSIS„ Large species. Body and appendages covered with sharp spines. Carapace as long as broad, greatest breadth 1.6-1.7 × distance between anterolateral spines; gastric and cardiac regions distinctly bordered by deep groove. Rostrum narrow and elongate, 2.1-2.3 × longer than broad, laterally with 2 pairs of dorso-anteriorly directed strong spines, breadth less than half carapace breadth at posterior carapace margin. Excavated sternum anteriorly produced, strongly ridged or cristate in midline on surface. Sternal plastron slightly broader than long; sternite 3 having anterior margin deeply excavated, with 2 submedian spines separated by deep notch; sternite 4 with 2 pairs of ventrally directed spines (anterior one smaller) on anterolateral margin and pair of submedian spines on posterior surface; posterolateral margin as long as anterolateral margin; anterolateral margin of sternite 5 with strong anterior spine, shorter (0.7) than posterolateral margin of sternite 4. Abdominal somite 1 with transverse row of 4 spines; somite 2 tergite 2.7-2.8 broa- der than long; pleuron anterolaterally blunt, posterolaterally strongly produced and tapering to sharp point; pleuron of somite 3 also tapering; somites 2-4 each with anterior row of 4-6 spines and posterior row of 6-9 spines; somite 5 with anterior row of 4-7 spines, posterior row of 4-9 spines, somite 6 with anterior row of 4-7 spines and posterior row of 4 spines and posterior marginal denticles; protopod of uropod with obsolescent protuberance on mesial margin; endopod 1.2-1.5 × longer than broad; telson half as long as broad, posterior plate 1.3-2.0 × longer than anterior plate, emarginate on posterior margin. Eyes proximally broadened in large specimens. Antennal peduncle extending far beyond cornea; article 2 with strong distolateral spine; antennal scale overreaching article 4, at most terminating in midlength of article 5; article 3 with distinct distomesial spine and small spine in ventral midline near juncture with article 4; articles 4 and 5 each with strong ventral distomesial spine; article 4 with additional spine at midlength of ventral surface in large specimens; article 5 as long as or slightly shorter than article 4, with small ventral spine about at midlength; flagellum consisting of 6-16 segments, falling short of distal end of P1 merus (in small specimens, slightly overreaching rostral tip). Mxp1 with bases close to each other. Mxp3 coxa with strong, ventrolaterally directed spine; basis unarmed or with obsolescent denticles on mesial ridge; ischium with strong distolateral spine (occasionally with small accompanying spine directly mesial to it), crista dentata with 25-30 denticles; merus twice (1.9-2.0 x) longer than ischium, with strong distolateral spine, flexor margin with laterally directed median spine, and 1-3 additional spines proximal to it, distolateral spine occasionally absent; carpus with strong distolateral spine and a few (usually 2) spines of small to good size on extensor surface. Pereopods spinose; P1 with spines roughly in 8 rows on merus, carpus and propodus; ischium with strong subterminal spine on ventromesial margin; merus slightly longer than carapace. P2-4 with dorsal (extensor), lateral and ventral (flexor) spines; meri successively shorter posteriorly (P3 merus 0.9 × length of P2 merus, P4 merus 0.8-0.9 × length of P3 merus), equally broad on P2-4; P2 merus as long as or slightly longer than carapace, 0.8-1.1 × longer than P2 propodus; P3 merus as long as P3 propodus, P4 merus 0.9-1.1 × length of P4 propodus; carpi subequal or successively slightly shorter posteriorly, slightly less than half as long as propodi on P2-4, distinctly longer than dactyli; propodi successively longer posteriorly, flexor margin straight, with pair of terminal spines preceded by row of spines placed in straight arrangement; dactyli slightly less than half length of propodi on P2-4, shorter than carpi in large specimens, subequal in small specimens (dactylus-carpus length ratio, 0.6-1.0 on P2 and P3, 0.7-1.1 on P4); flexor margin with row of 9-13 proximally diminishing slender spines subperpendicular to margin, ultimate more slender than penultimate.
Eggs. Number of eggs carried, more than 100; size, 1.02 mm × 1.13 mm - 1.57 mm × 1.58 mm.
Color. Illustrated by McCallum & Poore (2013) for a specimen from Western Australia. Male from Vanuatu (MNHN-IU-2014-16959): uniformly translucent pale orange; spines on pereopods proximally reddish, distally pale or whitish.
REMARKS„ The female (6.0 mm) from NORFOLK 2 Stn CP2111 (MNHN-IU-2014-16963) and another female (ovigerous, 7.5 mm) from BOA0 Stn CP2330 (MNHN-IU-2014-16958) bear an extra spine lateral to the submedian pair on the posterior surface of sternite 4, the feature as displayed by the larger of two western Australian specimens reported by McCallum & Poore (2013). Mentioning that this larger western Australian specimen differs from the holotype in having a more spinose carapace, with three instead of two strong rostral spines but the other smaller specimen agrees well with the holotype, McCallum & Poore believed these differences as allometric. All of our specimens, ranging from 3.6 to 13.2 mm, agree quite well with the holotype. However, the P2-4 dactyli in the specimens examined are shorter than the carpi in large specimens, subequal (or slightly longer on P4) in small specimens, with the dactylus-carpus length ratio, 0.6-1.0 on P2 and P3, 0.7-1.1 on P4, the feature apparent in the western Australian specimen of large size (McCallum & Poore 2013: fig. 8A).
Three closely related species, U. numerosus n. sp., U. quartanus n. sp. and U. senarius n. sp., are described in this paper. Their relationships are discussed under U. senarius (see below).
description: Published as part of Baba, Keiji, 2018, Chirostylidae of the Western and Central Pacific: Uroptychus and a new genus (Crustacea: Decapoda: Anomura), pp. 1-612 in Mémoires du Muséum national d'Histoire naturelle 212 on pages 489-491, DOI: 10.5281/zenodo.3760976