Uroptychus remotispinatus Baba & Tirmizi, 1979

Baba, Keiji, 2018, Chirostylidae of the Western and Central Pacific: Uroptychus and a new genus (Crustacea: Decapoda: Anomura), Tropical Deep-Sea Benthos (Mémoires du Muséum national d'Histoire naturelle 212), pp. 1-612 : 444-447

Uroptychus remotispinatus Baba & Tirmizi, 1979

Figure 222

Uroptychus remotispinatus Baba & Tirmizi,1979:52 , figs 1, 2.— Baba 2005:55.— Baba et al. 2009:57, figs 47-48.— Poore et al. 2011: 329,pl. 7,fig. H.

TYPE MATERIAL — Holotype: Japan, Bungo Strait between Kyushu and Shikoku, 1320 m, ov. female ( USNM 150318 ). [not examined].

MATERIAL EXAMINED — New Caledonia. BIOGEOCAL Stn CP216, 22°49’ S, 166°22’E, 2175-2250 m, 10.IV.1987, 2 ♂ 4.9, 6.9 mm, 1 ♀ 6.3 mm (MNHN-IU-2014-16930) . New Caledonia, Norfolk Ridge. BIOCAL Stn CP57, 23°44’S, 166°58’E, 1490-1620 m, 1.IX.1985, 1 ov. ♀ 6.4 mm (MNHN- IU-2014-16931) . – Stn CP60, 23°59’S, 167°08’E, 1530-1480 m, 02.IX.1985, with Acanella sp. ( Alcyonacea : Isididae ), 10 ♂ 7.1-8.7 mm, 8 ov. ♀ 5.8- 8.8 mm, 4 ♀ 6.1-7.4 mm (MNHN-IU-2014-16932) . – Stn CP61, 24°11’S, 167°34’E, 1070-1070 m, 02.IX.1985, 2 ♂ 4.2, 7.3 mm, 3 ov. ♀ 7.3-8.5 mm (MNHN-IU-2014-16933) . – Stn CP62, 24°19’S, 167°49’E, 1395-1410 m, 02.IX.1985, 1 ♂ 6.7 mm (MNHN-IU-2014-16934) . Wallis and Futuna Islands. MUSORSTOM 7 Stn DW620, 12°34’S, 178°11’W, 1280 m, 28.V.1992, with Acanella sp. ( Alcyonacea : Isididae ), 4 ♂ 5.5-7.8 mm, 4 ov. ♀ 7.2-8.8 mm, 4 ♀ 5.4-7.8 mm (MNHN-IU-2014-16935) . – Stn CP621, 12°35’S, 178°11’W, 1280-1300 m, with Acanella sp. ( Alcyonacea : Isididae ), 28.V.1992, 22 ♂ 5.5-10.1 mm, 23 ov. ♀ 7.0-10.0 mm, 20 ♀ 5.2-9.0 mm (MNHN-IU-2014-16936) . – Stn CP622, 12°34’S, 178°11’W, 1280-1300 m, with Acanella sp. ( Alcyonacea : Isididae ), 28.V.1992,17 ♂ 5.5-10.1 mm, 16 ov. ♀ 7.5-9.7 mm, 13 ♀ 4.1-9.3 mm (MNHN-IU-2014-16937) . – Stn CP623,12°34’S,178°15’W, 1280-1300 m, with Acanella sp. ( Alcyonacea : Isididae ), 28.V.1992, 17 ♂ 5.3-9.4 mm, 16 ov. ♀ 6.9-9.5 mm, 10 ♀ 4.0-9.3 mm (MNHN-IU-2014-16938) .

DISTRIBUTION„ Off Durban, off Mozambique, Madagascar Strait, Taiwan, Japan, and now New Caledonia, Norfolk Ridge and Wallis and Futuna Islands (SW Pacific); 850-2250 m.

SIZE„ Males, 4.2-10.1 mm; females, 4.0-10.0 mm; ovigerous females from 5.8 mm.

DIAGNOSIS„ Medium-sized species. Carapace: Slightly longer than broad, greatest breadth 1.5-1.6 × distance between anterolateral spines. Dorsal surface smooth; lateral margin with anterolateral spine reaching or overreaching lateral orbital angle, and small tubercle-like spines often obsolescent on anterior branchial margin, ridged along posterior portion. Rostrum short, varying from barely to fully reaching, rarely overreaching distal margin of cornea, with interior angle of 16-22°, dorsally flattish, straight horizontal or somewhat curving dorsally, length one-third that of carapace, breadth half carapace breadth at posterior carapace margin. Lateral limit of orbit angular usually without spine, rarely with small spine. Pterygostomian flap anteriorly roundish, bearing very small, often obsolescent spine. Excavated sternum inflated in center, with low longitudinal ridge in midline, anterior margin bluntly produced, often broad triangular; sternal plastron slightly broader than long, lateral extremities divergent posteriorly; sternite 3 shallowly depressed, anterior margin broadly concave with pair of median spines separated by small notch; anterolateral margin of sternite 4 with short anterior spine or process followed by a number of diminishing spines or tubercles, length nearly equal to that of posterolateral margin. Sternite 5 having anterolateral margin 0.6-0.7 × as long as posterolateral margin of sternite 4. Somite 2 tergite 2.2-2.6 × broader than long; pleuron posterolaterally blunt, lateral margin feebly or weakly concave and moderately divergent posteriorly; pleuron of somite 3 with blunt posterolateral terminus. Telson slightly more than half as long as broad; posterior plate 1.5-1.9 × longer than anterior plate, posterior margin emarginate. Eye short relative to breadth, 1.5 × longer than broad, slightly narrowed proximally, usually overreaching cornea; cornea 0.7 × as long as remaining eyestalk. Ultimate antennular article twice as long as high. Article 2 of antenna with short lateral spine. Antennal peduncle overreaching eye; antennal scale barely reaching, fully reaching or slightly overreaching distal end of article 4, occasionally slightly falling short of midlength of article 5; article 5 1.5 × longer than article 4, breadth 0.4 × height of antennular ultimate article; no spine on articles 4 and 5; flagellum of 14-16 segment not reaching distal end of P1 merus. Mxp1 with bases close to each other. Mxp3 basis with 3-5 denticles on mesial ridge; ischium having flexor margin distally not rounded, crista dentata with 16-22 denticles; merus 2.4 × longer than ischium, rather thick mesiolaterally, flexor margin distinctly ridged, not cristate, without spine; carpus unarmed. P1 4.4-4.9 × longer than carapace; slender, often denticulate on ventral surface of merus, with small ventro-distomesial and obsolescent ventro-distolateral spines on merus and carpus and short dorsal spine on ischium, unarmed elsewhere; merus 1.1-1.3 × longer than carapace; carpus 1.2 × (males), 1.2-1.4 × (females) longer than merus; palm shorter than (0.9 × in males, 0.8 × in females) carpus. Fingers proportionately broad distally, not crossing distally when closed; gaping in large males; movable finger 0.6 × (0.7 × in small females) length of palm, opposable margin with prominent proximal process disto-proximally broad in females, bidentate in males. P2-4 relatively long and slender; meri successively shorter posteriorly (P3 merus 0.9 × length of P3 merus, P4 merus 0.8-0.9 × length of P3 merus), equally broad on P2-4, dorsal margin moderately rounded, not sharply ridged; length-breadth ratio, 5.7-6.6 on P2, 5.3-5.9 on P3, 4.6-5.1 on P4; P2 merus 0.9 × (rarely 0.8 x) length of carapace, 1.2-1.3 × length of P2 propodus; P3 merus 1.1 × length of P3 propodus; P4 merus 0.9 × length of P4 propodus; carpi successively slightly shorter posteriorly, or subequal on P2 and P3 and slightly shorter on P4, longer than dactyli; carpus-propodus length ratio, 0.6-0.7 on P2 and P3, 0.5-0.7 on P4; propodi successively slightly longer posteriorly; flexor margin straight, with row of slender, movable spines (4-5 on P2, 4 on P3, 3 on P4), terminal spine single, considerably remote from juncture with dactylus; dactyli subequal on P2-4, 0.4 × length of propodi and 0.7-0.8 × length of carpi; slen- der, strongly curving; flexor margin with 2 groups of spines usually on P2, occasionally on P3 (additional spine between on P3 and P4), 2 distal spines remotely separated from proximal group, proximal group consisting of 4-6 spines, all spines strongly oblique but not oriented parallel to flexor margin, ultimate spine longer than penultimate.

Eggs. Number of eggs carried, 7-25; size, 1.6 mm × 1.5 mm - 2.30 mm × 2.50 mm.

Color. A specimen from Taiwan was illustrated by Baba et al. (2009) and Poore et al. (2011).

PARASITES„ Rhizocephalan externa on one male and one female from MUSORSTOM 7 Stn CP622 (MNHN- IU-2014-16937) and on one male and two females from Stn CP623 (MNHN-IU-2014-16938).

REMARKS„ The unique spination of the dactylus for which the species is named, is consistent without exception on P2; on P3 and P4, although, there is an additional spine that is present between the proximal and distal groups of spines and that is variable in location, being more or less close to the proximal group, more or less distant from that group or rarely equidistant between. Reexamination of the Madagascar specimens reported earlier ( Baba 1990: 947) disclosed that the spination is nearly the same as in the present material.

The rostrum also varies from barely reaching to fully reaching the cornea (rarely somewhat overreaching), but not extending as far forward as in the holotype ( Baba & Tirmizi 1979: fig. 1). In the Madagascar specimens, however, it usually considerably overreaches the eye, and in some specimens it is relatively short, only slightly overreaching the cornea as in the present material; P1 bears tubercles on mesial and ventral surfaces of the merus in large specimens of both sexes, and even on the carpus in large males.

The distalmost flexor marginal spine of the P2-4 propodi that is distantly remote from the juncture with the dactylus is one of the recognition characters of the species. This spination is shared with U. bispinatus Baba, 1988 (see above; Figure 38 ).

Figures

FIGURE 38 Uroptychus bispinatus Baba, 1988, A, D, male 5.5 mm; B, C, ovigerous female 5.4 mm (MNHN-IU-2014-16332). A, carapace, dorsal. B, carapace and anterior part of abdomen,lateral.C, sternal plastron,with excavated sternum and basal parts of Mxp1.D, distal part of left P2,lateral.Scale bars:1 mm.

FIGURE 222 Uroptychus remotispinatus Baba & Tirmizi,1979,A, C, D, E, G, I, male 9.0 mm (MNHN-IU-2014-16936);B, F, H,J, ovigerous female 7.3 mm,Madagascar,Vauban Stn CH138 (MNHN-Ga1523).A, B, anterior part of carapace,dorsal.C, carapace and anterior part of abdomen,lateral.D, distal part of left P1, dorsal. E, F, left P2,distal articles,setae omitted, lateral.G, H, left P3, distal articles, setae omitted, lateral.I, J, left P4,distal articles, setae omitted, lateral.Scale bars:1 mm.