Uroptychus bardi McCallum & Poore, 2013

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 : 91-93

Uroptychus bardi McCallum & Poore, 2013

Figure 30

Uroptychus bardi McCallum & Poore, 2013: 158 , fig.4.

TYPE MATERIAL — Holotype: Western Australia, off Cape Leveque (14°33.43’S, 121°20.38’E - 14°32.76’S, 121°19.65’E), 924-1101 m, male ( NMV J63754 ). [not examined].

MATERIAL EXAMINED — Wallis and Futuna Islands. MUSORSTOM 7 Stn DW539, 12°27’S, 177°27’E, 700 m, 17.V.1992, 1 ♂ 10.0 mm ( MNHN- IU-2014-16316). – Stn DW 615, 14°27’S, 177°26’W, 700-750 m, with Chrysogorgiidae gen. sp. ( Calcaxonia ), 27.V.1992, 1 ♂ 12.5 mm ( MNHN- IU-2014-16317); 1 ov. ♀ 11.8 mm (MNHN-IU-2014-16318). Vanuatu. MUSORSTOM 8 Stn CP 1074, 15°48.42’S, 167°24.27’E, 775-798 m, 4.X.1994, 1 ov. ♀ 9.1 mm (MNHN-IU-2014-16319) .

DISTRIBUTION„ Western Australia off Cape Leveque, 924-1101 m, and now Wallis and Futuna Islands (SW Pacific) and Vanuatu, 700- 798 m.

SIZE„ Males, 10.0- 12.5 mm; ovigerous females, 9.1-11.8 mm.

DESCRIPTION„ Large species. Carapace: Slightly broader than long (0.9 × as long as broad); greatest breadth 1.9 × distance between anterolateral spines. Dorsal surface glabrous, moderately convex from anterior to posterior, without distinct border between gastric and cardiac regions; epigastric region feebly or barely granulose. Lateral margins convexly divergent posteriorly (greatest breadth of carapace measured at posterior third), with row of short, oblique, granulate ridges along branchial region; anterolateral spine well developed, extending far beyond much smaller lateral orbital spine, situated slightly posterior to level of, but moderately remote from that spine. Rostrum sharp triangular, with interior angle of 25°; length about one-third postorbital carapace length, breadth less than half carapace breadth measured at posterior carapace margin; dorsal surface flattish, ventral surface straight horizontal. Pterygostomian flap anteriorly angular, ending in small but distinct spine; surface smooth.

Sternum: Excavated sternum with convex anterior margin bearing 1 or 2 small median spines, surface with or without small spine in center. Sternal plastron 0.8-0.9 × as log as broad, posteriorly broadened. Sternite 3 strongly depressed, anterior margin deeply excavated in V-shape, with 2 submedian spines separated by narrow notch, anterolateral corner sharp angular or rounded. Sternite 4 long relative to breadth; surface with tubercles on posterior portion; anterolateral margin strongly produced forward, slightly falling short of anterior end of sternite 3; posterolateral margin half length of anterolateral margin. Anterolateral margin of sternite 5 strongly convex, much longer than posterolateral margin of sternite 4.

Abdomen: Smooth and glabrous. Somite 1 without transverse ridge. Somite 2 tergite 2.5-2.6 × broader than long; pleural lateral margins concavely divergent posteriorly, anterior end rounded, posterior end angular. Telson half as long as broad; posterior plate moderately concave on posterior margin, length 1.5-1.6 × that of anterior plate.

Eye: Long relative to breadth (length 1.8 × breadth), reaching distal quarter to tip of rostrum; mesial margin somewhat concave. Cornea slightly dilated, broader than remaining eyestalk, length more than half that of remaining eyestalk.

Antennule and antenna: Ultimate article of antennule 2.3-2.6 × longer than high. Antennal peduncle slender, reaching rostral tip. Article 2 with strong distolateral spine. Antennal scale much broader than peduncle, nearly or barely reaching distal end of article 5. Distal 2 articles unarmed; article 5 2.7 × longer than article 4, breadth about half height of ultimate antennular article. Flagellum of 22-30 segments falling short of distal end of P1 merus.

Mxp: Mxp1 with bases close to each other but not contiguous. Mxp3 barely setose on lateral surface. Basis having mesial ridge with 5-7 denticles diminishing toward proximal end of article. Ischium with 24-26 denticles on crista dentata, flexor margin distally not rounded. Merus and carpus unarmed; merus 2.2 × longer than ischium, relatively slender, flexor margin moderately ridged.

P1: 5.1-5.8 × longer than carapace, relatively massive, glabrous except for fingers. Ischium dorsally with welldeveloped curved spine, ventromesially with tubercle-like spines, without subterminal spine. Merus 1.2-1.4 × longer than carapace, ventral surface with tubercles in longitudinal row and blunt low distal spine near each of mesial and lateral margins. Carpus 1.2-1.3 × longer than merus. Palm 2.1-2.6 × longer than broad, slightly shorter than carpus. Fingers distally incurved, crossing when closed, gaping in males in proximal two-thirds, fitting when closed in distal half, not gaping in females; length more than half (0.53-0.67) that of palm; opposable margin of movable finger with strong blunt median process on gaping portion in males, disto-proximally broad process on proximal third in females (and on right P 1 in smaller male).

P2-4: Relatively slender, compressed mesio-laterally, with sparse long setae. Meri successively shorter posteriorly (P3 merus 0.9 × length of P2 merus; P4 merus 0.8 × length of P3 merus), subequal in breadth on P2-4, dorsal margin smooth; length-breadth ratio, 6.0 on P2, 5.0-6.0 on P3, 5.0 on P4; P2 merus as long as carapace, 1.2 × longer than P2 propodus; P3 merus subequal to P3 propodus; P4 merus 0.90-0.96 × length of P4 propodus. Carpi relatively long, 0.6 × length of propodus on P2 and P3, 0.5 × on P4; P3 carpus subequal to or slightly shorter than P2 carpus, P4 carpus 0.8- 0.9 × length of P3 carpus. Propodi successively slightly shorter posteriorly or subequal on P2 and P3 and shortest on P4; flexor margin slightly curving, ending in pair of spines preceded by 10-12 spines on entire length on P2, 8 or 9 on P3, 6 on P4. Dactylus relatively short; dactylus-propodus length ratio, 0.30-0.36 on P2-4; dactyls-carpus length ratio, 0.5 on P2, 0.6 on P3, 0.7 on P4; strongly curving at proximal third; flexor margin with 11-14 loosely arranged, obliquely directed, sharp, proximally diminishing spines.

Eggs. Number of eggs carried, 6-23; size, 1.48 mm × 1.56 mm - 1.60 mm × 1.77 mm.

REMARKS — The species strongly resembles U. litosus Ahyong & Poore, 2004 . In addition to the differences given by McCallum & Poore (2013), U. bardi is distinguished from that species by the following: the P2 propodus bears 10-12 instead of 7-8 spines proximal to a pair of terminal spines, along the entire length instead of the distal half of the flexor margin; the excavated sternum anteriorly ends in a rounded margin, not angular as in U. litosus ; and the P4 merus is as broad as instead of distinctly narrower than the P3 merus.

Figures

FIGURE 30 Uroptychus bardi McCallum & Poore,2013,male 12.5 mm (MNHN-IU-2014-16317).A, carapace and anterior part of abdomen,proximal part of right P1 included, dorsal. B, same, lateral. C, sternal plastron,with excavated sternum and basal parts of Mxp1. D, left antenna, ventral. E, right Mxp3, lateral. F, same, ventral. G, right P1, proximal part, ventral. H, same, dorsal. I, right P2, lateral. J, same, distal part, setae omitted,lateral. Scale bars:A, B, G, H, I, 5 mm; C, D, E,F, J,1 mm.