Uroptychus longicarpus, Baba, 2018

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 : 273-277

Uroptychus longicarpus n. sp.

Figures 126 , 127

TYPE MATERIAL — Holotype: New Caledonia, Norfolk Ridge. MUSORSTOM 4 Stn CP215, 22°55.7’S, 167°17.0’E, 485- 520 m, 28.IX.1985, ♂ 7.5 mm ( MNHN-IU-2014-16621 ) . Paratypes: New Caledonia, Norfolk Ridge. MUSORSTOM 4, collected with holotype, 4 ♂ 5.4-8.0 mm, 7 ov. ♀ 7.1-7.3 mm, 1 ♀ 7.0 mm (MNHN-IU-2014-16622) . – Stn CP214, 22°53.8’S, 167°13.9’E, 425-440 m, 28.IX.1985, 2 ♂ 6.8, 7.3 mm, 2 ov. ♀ 6.7, 9.0 mm (MNHN-IU-2014-16623) . – Stn DW229, 22°51.5’S, 167°13.5’E, 445-460 m, 30.IX.1985, 4 ♂ 4.6-7.1 mm, 4 ov. ♀ 5.5-7.2 mm, 2 ♀ 4.3, 4.9 mm (MNHN- IU-2014-16624) . NORFOLK 1 Stn DW1733, 22°56’S, 167°15’E, 427-433 m, 28.VI.2001, 3 ♂ 5.4-7.7 mm, 6 ov. ♀ 5.8- 7.6 mm (MNHN-IU-2014-16625) . – Stn DW1734, 22°53’S, 167°12’E, 403-429 m, 28.VI.2001, 1 ♂ 5.9 mm, 4 ov. ♀ 5.5- 6.3 mm (MNHN-IU-2014-16626) . NORFOLK 2 Stn CP2146, 22°50.17’S, 167°17.35’E, 518-518 m, 4.XI.2003, 2 ov. ♀ 7.0, 7.5 mm (MNHN-IU-2014-16627) . – Stn DW2147, 22°49.80’S, 167°16.09’E, 496 m, 4.XI.2003, 8 ♂ 4.4-6.2 mm, 2 ov. ♀ 5.7, 6.0 mm (MNHN-IU-2014-16628) . – Stn DW2148, 22°44.20’S, 167°15.97’E, 386-391 m, 4.XI.2003, 1 ov. ♀ 6.7 mm (MNHN-IU-2014-16629) . – Stn DW2155, 22°52.40’S, 167°13.46’E, 453-455 m, 5.XI.2003, 2 ♂ 5.3, 5.9 mm, 1 ov. ♀ 5.7 mm (MNHN-IU-2014-16630) . – Stn DW2156, 22°54.19’S, 167°15.13’E, 468-500 m, 5.XI.2003, 5 ♂ 5.4-7.3 mm, 3 ♀ 4.0-5.5 mm (MNHN-IU-2014-16631) . New Caledonia. MUSORSTOM 4 Stn DW162, 18°35’S, 163°10’E, 535 m, 16.IX.1985, 1 ♂ 6.5 mm (MNHN-IU-2014-12793) .

OTHER MATERIAL EXAMINED — Vanuatu. MUSORSTOM 8 Stn CP1026,17°50’S,168°39’E, 437-504 m, 28.IX.1994, 1 ♂ 6.7 mm, 1 ov.♀ 6.8 mm, 1 ♀ 7.0 mm (MNHN-IU-2014-16632) . – Stn CP1136, 15°41’S, 167°02’E, 398-400 m, 11.X.1994, 1 ♀ 7.0 mm (MNHN-IU-2014-16633) . – Stn CP975, 19°23.60’S, 169°28.93’E, 566-536 m, 22.IX.1994, 1 ♂ 5.5 mm, 1 ov. ♀ 6.3 mm (MNHN-IU-2014-16634) . – Stn CP975, 19°24’S, 169°29’E, 566-536 m, 22.IX.1994, 1 ♀ 5.7 mm (MNHN-IU-2014-16635) . – Stn CP1088, 15°09’S, 167°15’E, 425-455 m, 6.X.1994, 1 ♂ 7.3 mm (MNHN-IU-2014-16636) . New Caledonia, Loyalty Ridge. MUSORSTOM 6 Stn CP464, 21°01’S, 167°32’E, 430-420 m, 21.II.1989, 2 ov. ♀ 7.4, 7.6 mm (MNHN-IU-2014-16637) . – Stn DW478,21°08.96’S,167°54.28’E,400 m, 22.II.1989,1 ov.♀ 6.7 mm (MNHN-IU-2014-16638) . New Caledonia, Isle of Pines.500 m, 12.V.1978,coll.Intes, 1 ov.♀ 6.9 mm (MNHN-IU-2014-16639) . New Caledonia, Norfolk Ridge. BATHUS 2 Stn DW719,22°48’S,167°15’E,444-445 m,11.V.1993,1 ♀ 5.6 mm (MNHN-IU-2014-16640) . SMIB 4 Stn DW68, 22°55’ S, 167°16’E, 430-440 m, 10.III.1989, 1 ov. ♀ 6.9 mm (MNHN-IU-2014-16641) . BIOCAL Stn DW44, 22°47’S, 167°14’E, 440-450 m, 30.VIII.1985, 3 ♂ 5.3-5.9 mm, 4 ov. ♀ 4.9-6.8 mm (MNHN-IU-2014-16642) . – Stn CP45, 22°47’S, 167°15’E, 430-465 m, 30.VIII.1985, 3 ♂ 6.0-7.3 mm, 1 ov. ♀ 6.2 mm, 1 ♀ 5.7 mm (MNHN-IU-2014-16643) . SMIB 2 Stn DW03, 22°54’S, 167°14’E, 412-428 m, 17.IX.1986, 3 ♂ 5.8-7.1 mm, 3 ov.♀ 5.8-6.2 mm (MNHN-IU-2014-16644) . – Stn DW06,22°55’S,167°16’E, 442-460 m, 17.IX.1986,1 ♂ 7.8 mm,1 ov.♀ 7.3 mm, 2 ♀ 4.5, 4.6 mm (MNHN-IU-2014-16645) . – Stn DW08, 22°53’S, 167°14’E,435-447 m, 18.IX.1986,2 ♂ 5.9, 6.7 mm, 1 ♀ 6.2 mm (MNHN-IU-2014-16646) . – Stn DW09,22°55’S,167°16’E,475-500 m, 18.IX.1986,2 ♂ 5.5,5.7 mm,1 ov.♀ 6.6 mm (MNHN-IU-2014-16647) . – Stn DW10,22°55’S,167°16’E,490-495 m, 18.IX.1986, 1 ov. ♀ 6.6 mm (MNHN-IU-2014-16648) . – Stn DW13, 22°52’S, 167°13’E, 427-454 m, 18.IX.1986, 1 ♂ 6.3 mm (MNHN-IU-2014-16649) . – Stn DW14, 22°53’S, 167°13’E, 405-444 m, 18.IX.1986, 2 ♂ 5.6, 7.5 mm, 1 ♀ 4.8 mm (MNHN-IU-2014-16650) . SMIB 3 Stn DW21, 23°00’S, 167°19’E, 525-525 m, 24.V.1987, 1 ♂ 6.2 mm, 1 ov. ♀ 7.3 mm (MNHN-IU-2014-16651) . – Stn DW22, 23°03’S, 167°19.1’E, 503 m, 24.V.1987, 2 ♂ 4.7, 6.4 mm, 2 ov. ♀ 6.4,7.0 mm (MNHN-IU-2014-16652) . – Stn DW26, 22°55’S, 167°16’E, 450 m, 24.V.1987, 1 ♂ 5.7 mm (MNHN-IU-2014-16653) .

ETYMOLOGY„ From the Latin longus (long) plus carpus (carpus, hand), referring to the P4 carpus, which is longer than

the P3 carpus, a distinctive character to separate the new species from congeners.

DISTRIBUTION„ Vanuatu, Loyalty Islands, New Caledonia, Isle of Pines, and Norfolk Ridge; 386- 525 m.

SIZE„ Males, 4.4-8.0 mm; females, 4.0-9.0 mm; ovigerous females from 4.9 mm. DESCRIPTION„ Medium-sized species. Carapace: As long as broad; greatest breadth 1.5 × distance between anterolateral spines. Dorsal surface smooth and glabrous, slightly convex in profile, with feeble depression between gastric and cardiac regions. Lateral margins somewhat convex, bearing 2 distinct spines: first anterolateral spine reaching or slightly overreaching lateral orbital spine; second larger than first, situated at anterior end of branchial margin, followed by row of several tubercles or denticles reaching between midlength and posterior third of branchial margin. Rostrum broad triangular, with interior angle of 40-42°, nearly horizontal; dorsal surface concave; length 0.4-0.5 × postorbital carapace length, breadth slightly more than half carapace breadth at posterior carapace margin. Lateral orbital spine much smaller than anterolateral spine, situated slightly anterior to level of that spine. Pterygostomian flap anteriorly roundish, with very small spine; surface smooth.

Sternum: Excavated sternum anteriorly ending in sharp spine, surface with small, laterally compressed spine or process in center. Sternal plastron as long as broad, lateral extremities gently divergent posteriorly. Sternite 3 depressed well; anterior margin deeply excavated, with 2 well-developed submedian spines nearly contiguous or separated by narrow V-shaped notch, anterolateral angle rounded. Sternite 4 having relatively long anterolateral margin slightly convex, anteriorly produced to spine of moderate-size, 3-4 × longer than posterolateral margin. Anterolateral margin of sternite 5 convexly divergent posteriorly, much longer than posterolateral margin of sternite 4.

Abdomen: Tergites smooth and glabrous. Somite 1 gently convex from anterior to posterior. Somite 2 tergite 2.4-2.7 × broader than long; pleural lateral margins strongly divergent posteriorly, with bluntly angular terminus. Pleuron of somite 3 laterally angular. Telson 0.6 × as long as broad; posterior plate 1.7-1.9 × (rarely 1.4 x) longer than anterior plate, posterior margin slightly or moderately emarginate.

Eye: Elongate, 2.0-2.4 × longer than broad, mesial and lateral margins concave, distally somewhat broadened, falling short of rostral tip. Cornea dilated, slightly more than half as long as remaining eyestalk.

Antennule and antenna: Ultimate article of antennular peduncle 2.0-2.4 × longer than high. Antennal peduncle barely reaching distal end of cornea. Article 2 with distolateral spine usually very small, occasionally barely discernible. Antennal scale reaching or slightly falling short of distal end of article 5, breadth about twice that of article 5. Article 4 unarmed. Article 5 2.4-3.2 × longer than article 4, with small distomesial spine, breadth 0.4-0.5 × height of ultimate antennular article. Flagellum of 16-23 segments reaching distal end of P1 merus.

Mxp: Mxp1 with bases close to each other. Mxp3 basis with 2 denticles on mesial ridge, distal one distinct, proximal one obsolescent and often absent. Ischium with 18-21 distally diminishing denticles on crista dentata, flexor margin distally not rounded. Merus 2 × as long as ischium, flexor margin sharply ridged, unarmed, with row of long setae; mesial face flattish. Carpus unarmed.

P1: Somewhat massive in males, nearly glabrous except for distal articles, length 4.5-5.3 × that of carapace. Ischium with strong sharp dorsal spine, unarmed elsewhere. Merus 1.1-1.2 × longer than carapace, granulose on ventral surface, lateral and mesial distoventral spines obsolete. Carpus denticulate ventrally, 1.0-1.3 × longer than merus. Palm 2.4-2.7 × (males), 2.7-2.9 × (females) longer than broad, 0.9-1.0 × length of carpus, breadth slightly more than distance between lateral orbital spines in large males; with fine tubercles on ventral surface in large males (> 6.3 mm), smooth in females and small males. Fingers distally incurved, crossing when closed; movable finger 0.5-0.6 × length of palm; in males, moderately or largely gaping, fitting to each other on distal third; opposable margin with proximo-distally very broad eminence on gaping margin, opposable margin of fixed finger largely concave on proximal two-thirds; in females, fingers not gaping, movable finger with broad proximal process proximal to opposite eminence on fixed finger.

P2-4: Relatively slender, compressed mesio-laterally, with sparse long setae. Meri equally broad on P2-4; lengthbreadth ratio, 5.3-6.5 on P2, 5.2-6.4 on P3, 5.2-6.2 on P4; P3 merus 0.9 × length of P2 merus, P4 merus 0.9-1.0 × length of P3 merus; dorsal margins unarmed, ventrolaterally with obsolescent distal spine; P2 merus 0.90-0.95 × length of carapace, 1.5-1.6 × length of P2 propodus; P3 merus 1.3 × length of P3 propodus; P4 merus 1.1-1.2 × length of P4 propodus, Carpi unarmed, subequal in length on P2 and P3, longest on P4 (P4 carpus 1.1-1.2 × longer than P3 carpus), much longer than dactyli (carpus-dactylus length ratio, 1.7-2.0 on P2, 1.5-1.9 on P3, 1.6-2.0 on P4); carpus-propodus length ratio 0.5-0.6 on P2-4. Propodi successively longer posteriorly; flexor margin nearly straight, ending in pair of spines very close to juncture with dactylus, preceded by row of 7-10 relatively long movable spines on P2, 7-9 spines on P3, 6-9 spines on P4 (on distal 5/6 on P2, slightly more distal on P3 and P4). Dactyli 0.3-0.4 × length of propodi and 0.5-0.6 length of carpi on P2-4; flexor margin curving at proximal third, ending in strong spine preceded by 7-8 subtriangular spines more or less closely arranged, somewhat inclined and diminishing toward base of article, ultimate spine distinctly larger and broader than penultimate.

Eggs. Number of eggs carried, ca. 30, 1.27 mm × 1.32 mm - 1.40 × 1.64 mm.

REMARKS — The second lateral marginal spine of the carapace is rarely reduced to small size (in the male from Vanuatu, MNHN-IU-2014-16636) or tubercle-like process (in the specimens from Vanuatu, MNHN-IU-2014-16632). In large

specimens more than 9.0 mm long, additional spine is present directly mesial to the second spine, as also are a few similar spines between the first and second.

This new species strongly resembles U. sibogae Van Dam, 1933 (see below) and U. nebulosus n. sp. in nearly all aspects. As suggested by the species name, however, the P4 carpus in U. longicarpus is consistently longer than the P3 carpus, instead of being 0.8-0.9 times as long in the congeners.

In the key to species, the species is closely set to U. politus ( Henderson, 1885) , but it actually is rather distant in having a spine of good size at the anterior end of the branchial margin, which is reduced to an elevated ridge, in having sternite 5 with a well convex rather than feebly convex or nearly straight anterolateral margin, and most noticeably in having the P4 carpus longer than the P3 carpus.

Figures

FIGURE 126 Uroptychus longicarpus n.sp.,holotype,male 7.5 mm (MNHN-IU-2014-16621).A,carapace and anterior part of abdomen,proximal part of left P1 included,dorsal.B, same, lateral.C, sternal plastron, with excavated sternum and basal parts of Mxp1. D, telson. E, left antenna,ventral. F, right Mxp3,ventral.G, left P1,basal articles omitted, dorsal.Scale bars:A,B, G,5 mm; C,D,E,F,1 mm.

FIGURE 127 Uroptychus longicarpus n. sp., holotype, male 7.5 mm (MNHN-IU-2014-16621). A, right P2, lateral. B, same,distal part, setae omitted, lateral.C, right P3, setae omitted, lateral. D, same,distal part,lateral.E, right P4,lateral. Scale bars:1 mm.