Uroptychus australis ( Henderson, 1885 )

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 : 74-80

Uroptychus australis ( Henderson, 1885)

Figures 20-23

Diptychus australis Henderson, 1885: 420 (part; specimens from Port Jackson and off Banda Island [Not specimens from north of the Kermadec Islands]; see below for designation of lectotype).

Uroptychus australis — Henderson 1888: 179 (part),pl. 21: figs 4, 4a-4c (specimens from Port Jackson and off Banda). — Ahyong & Poore 2004:18, fig. 3. — Baba 2005:224 (designation of lectotype: ♂, BMNH 88:33, Challenger Stn 164). — Poore et al. 2008: 17 (fig.).

Not Uroptychus australis var. indicus — Van Dam 1933: 18, figs 25-28 (see under U.vandamae ).

Not Uroptychus australis var. indicus — Tirmizi 1964: 394 (undescribed species).

TYPE MATERIAL — Lectotype: Australia, Port Jackson . CHALLENGER Stn 164, 39°13’S, 151°38’E, 410 fms (746 m), 1 ♂ 4.4 mm ( BMNH 88:33 ). [Examined] . Paralectotypes: same data as for the lectotype, 1 ov. ♀ 7.2 mm, 1 ♀ 7.5 mm (BMNH 88:33). [Examined] . Indonesia, off Banda. CHALLENGER Stn 194, 4°31’00”S, 129°57’20”E, 360 fms (655 m), 1 ♂ 4.8 mm, 1 ♀ 5.0 mm (BMNH 88:33). [Examined] .

OTHER MATERIAL EXAMINED — Solomon Islands. SALOMON 1 Stn DW1827,9°59.1’S,161°05.8’E,804-936 m, 4.X.2001,1 ov.♀ 7.0 mm (MNHN- IU-2014-17319) . SALOMON 2 Stn CP2197, 8°24.2’S,159°22.5’E,897-1057 m, 24.X.2004,1 ♂ 6.8 mm,2 ov. ♀ 6.2, 6.5 mm (MNHN-IU-2014-17320) . – Stn CP2230, 6°27.8’S, 156°24.3’E, 837-945 m, 29.X.2004, 18 ♂ 5.1-7.7 mm, 24 ov. ♀ 5.9-7.5 mm, 8 ♀ 4.1-6.5 mm (MNHN-IU-2014-17321) . – Stn CP2253, 7°26.5’S, 156°15.0’E, 1200-1218 m, 2.XI.2004, 1 ♀ 5.4 mm (MNHN-IU-2014-17322) . – Stn CP2289, 8°19.6’S, 160°01.9’E, 660-854 m, 7.XI.2004, 2 ♂ 5.8, 6.4 mm, 2 ov. ♀ 5.3, 5.6 mm, 2 ♀ 4.3, 4.8 mm (MNHN-IU-2014-17323) . – Stn CP2297, 9°08.8’S, 158°16.0’E, 728-777 m, 8.XI.2004, 4 ♂ 4.3-7.5 mm, 3 ov. ♀ 6.0-6.9 mm, 2 ♀ 5.1, 6.7 mm (MNHN-IU-2014-17324) . Wallis and Futuna Islands. MUSORSTOM 7 Stn CP550, 12°15’S, 177°28’W, 800-810 m, Chrysogorgia sp. ( Calcaxonia , Chrysogorgiidae ), 18.V.1992, 1 ♂ 6.8 mm (MNHN-IU-2014-17325) , 1 ♂ 5.7 mm (MNHN-IU-2014-17326) . – Stn CP551, 12°15’S, 177°28’W, 791-795 m, 18.V.1992, 1 ♀ 6.5 mm (MNHN-IU-2014-17327) , 1 ♀ 7.5 mm (MNHN-IU-2014-17328) . – Stn CC553, 12°17’S, 177°28’W, 780-794 m, with corals of Chrysogorgiidae (Calcaxonia) , 18.V.1992, 1 ♂ 7.5 mm (MNHN-IU-2014-17329) , 1 ov. ♀ 7.5 mm (MNHN-IU-2014-17330) . Vanuatu. MUSORSTOM 8 Stn CP992,18°52.34’S,168°55.16’E,748-775m, 24.IX.1994,2 ♂ 5.4,6.0 mm (MNHN-IU-2014-17331) . – Stn CP993,18°48.78’S, 168°54.04’ E 780-783 m 24.IX.1994, 3 ♂ 5.4-6.4 mm, 1 ov.♀ 7.0 mm, 2 ♀ 6.5, 7.2 mm (MNHN-IU-2014-17332) . – Stn CC996,8°52.41’S,168°55.73’E, 764- 786 m, 24.IX.1994,2 ♂ 5.8,6.5 mm,1 ov.♀ 6.7 mm (MNHN-IU-2014-17333) . – Stn CP1036,18°01.00’ S,168°48.20’E,920-950 m, 29.IX.1994,1 ♂ 6.2 mm, 1 ov. ♀ 7.1 mm (MNHN-IU-2014-17334) . – Stn CP1074, 15°48.42’S, 167°24.27’E, 775-798 m, 4.X.1994, 1 ov. ♀ 6.9 mm (MNHN-IU-2014-17335) . – Stn CP1080, 15°57.30’ S, 167°27.73’E, 799-850 m, 5.X.1994, 7 ♂ 6.3-7.8 mm, 7 ov. ♀ 6.3-7.1 mm, 2 ♀ 7.1, 7.2 mm (MNHN-IU-2014-17336) . – Stn DW1128, 16°02.14’S,166°38.39’E,778-811 m, 10.X.1994,1 ov.♀ 6.0 mm (MNHN-IU-2014-17337) . SANTO Stn AT62,15°41.5’S,167°58.0’ E, 830-918 m, 4.X.2006, 1 ov. ♀ 7.7 mm (MNHN-IU-2014-17338) . Tonga. BORDAU 2 Stn CP1565, 20°58’S, 175°16’W, 869-880 m, 9.VI.2000, 2 ♂ 6.7, 7.7 mm, 2 ov. ♀ 6.3, 6.9 mm, 1 ♀ 6.9 mm (MNHN-IU-2014-17339) . – Stn DW1588, 18°40’S, 173°52’W, 630-710 m, 13.VI.2000, 1 ♀ 5.8 mm (MNHN-IU-2014-17340) . – Stn CP1600, 20°48’S,174°52’W,902-907 m, Chrysogorgiidae gen.sp.( Calcaxonia ),15.VI.2000,4 ♂ 3.7-6.0 mm, 1 ov.♀ 5.7 mm, 1 ♀ 4.2 mm (MNHN-IU-2014-17341) . – Stn CP1613, 23°03’S, 175°47’W, 331-352 m, 17.VI.2000, 1 ♀ 7.1 mm (MNHN-IU-2014-17342) . – Stn CP1625, 23°28’S, 176°22’W, 824 m, 19.VI.2000, 2 ov. ♀ 6.2, 6.9 mm (MNHN-IU-2014-17343) . New Caledonia. BATHUS 4 Stn CP951, 20°31.44’S, 164°54.97’E, 960 m, 10.VIII.1994, 1 ov. ♀ 6.7 mm (MNHN-IU-2014-17344) . BATHUS 2 Stn CP742, 22°33’S, 166°25’E, 340-470 m, 14.V.1993, 1 ♂ 5.1 mm (MNHN-IU-2014-17345) . HALIPRO 1 Stn CH 876, 23°10’S, 166°49’E,870-1000 m, 31.III.1994,1 ♀ 7.8 mm (MNHN-IU-2014-17346) . New Caledonia, Loyalty Ridge. MUSORSTOM 6 Stn CP438,20°23.00’S, 166°20.10’E, 800 m, 18.II.1989, 2 ♂ 7.3,7.7 mm, 4 ov. ♀ 5.7-6.0 mm (MNHN-IU-2014-17347) . – Stn CP427, 20°23.35’S, 166°20.00’E, 800 m, 17.VII.1989, 1 ov. ♀ (carapace broken) (MNHN-IU-2014-17348) . BIOGEOCAL Stn CP290,20°36.91’S, 167°03.34’ E,760-920m,27.IV.1987, 1 ♂ 7.0 mm, 1 ov. ♀ 6.9 mm, 2 ♀ 4.6, 6.2 mm (MNHN-IU-2014-17349) . New Caledonia, Loyalty Basin. BIOGEOCAL Stn CP232, 21°33.81’S, 166°27.07’E, 760-790 m, 12.IV.1987, 1 ♂ 8.1 mm, 1 ♀ 7.2 mm (MNHN-IU-2014-17350) . New Caledonia, Hunter and Matthew Islands.VOLSMAR Stn DW04, 22°24.7’S, 171°49.0’E, 825-850 m, 1.VI.1989,2 ♂ 4.6,6.9 mm,1 ov.♀ 6.0 mm (MNHN-IU-2014-17352) . – Stn CP26,22°22.8’S,171°21.4’E,915-980 m, 4.VI.1989,1 ♂ 6.5 mm,2 ♀ 4.5,6.0 mm (MNHN-IU-2014-17353) . New Caledonia, Norfolk Ridge.BATHUS 3 Stn CP844,23°06’S,166°46’E,908 m,1.XII.1993,1 ♂ 7.9 mm,4 ov.♀ 5.8-6.3 mm,2 ♀ 5.3,5.8 mm (MNHN-IU-2014-17354) . BIOCAL Stn CP31,23°08’S,166°51’E, 850 m, 29.VIII.1985, 1 ov. ♀ 7.3 mm (MNHN-IU-2014-17355) , 1 ov.♀ 7.1 mm (MNHN-IU-2014-17356) . NORFOLK 2 Stn DW2054, 23°39.62’ S, 168°15.17’ E,736-800 m, 24.X.2003, 1 ♂ 6.8 mm, 1 ♀ 8.4 mm (MNHN-IU-2014-17357) . – Stn DW2066, 25°16.90’S, 168°55.11’E, 834-870 m, 26.X.2003, 3 ♂ 4.7-6.3 mm (MNHN-IU-2014-17358) . – Stn DW2080, 25°20.40’S, 168°18.74’ E, 764- 816 m, 27.X.2003, 2 ♂ 2.7 mm, carapace broken, 2 ov. ♀ 5.3, 5.7 mm (MNHN-IU-2014-17359) . New Caledonia, Lord Howe Rise. No cruise name, Stn Dr 2, 379-391 m, X.1999,1 ♀ 6.9 mm (MNHN-IU-2014-17360) . Kiribati. 750 m, IV.1987, coll. Crutz, 1 ov. ♀ 7.1 mm (MNHN-IU-2014-17351) .

DISTRIBUTION„ Western Australia, New South Wales, Victoria and Tasmania, Makassar Strait, off Banda, in 458- 1150 m; and now Solomon Islands, Wallis and Futuna Islands, Vanuatu, Tonga, Loyalty Islands, New Caledonia, Kiribati, Hunter-Matthew, Norfolk Ridge, Lord Howe Rise, in 331-1218 m.

SIZE„ Males, 3.7-8.1 mm; females, 4.1-7.5 mm; ovigerous females from 5.3 mm.

DESCRIPTION„ Medium-sized species. Carapace: Slightly longer than broad (length 1.1 × breadth); greatest breadth 1.6 × distance between anterolateral spines. Dorsal surface smooth and glabrous, without depression between gastric and cardiac regions; gastric region somewhat inflated in profile, distinctly elevated from level of rostrum, bearing pair of small epigastric spines or tubercles often obsolete. Lateral margins somewhat convexly divergent posteriorly, with ridge along posterior third or posterior half of length; anterolateral spine small, somewhat larger than, separated well from, and barely reaching tip of, lateral orbital spine. Rostrum sharp, narrow triangular, straight horizontal, with interior angle of 18-20°; length less than half that of remaining carapace, breadth half carapace breadth measured at posterior carapace margin; dorsal surface flattish or slightly concave. Pterygostomian flap anteriorly ending in small spine, smooth on surface.

Sternum: Excavated sternum with small central process often absent on somewhat elevated ridge in midline, anteriorly sharply produced. Sternal plastron gradually broadened posteriorly, length about four-fifths breadth. Sternite 3 moderately or strongly depressed from level of sternite 4, anterior margin deeply excavated, with pair of submedian spines, laterally rounded or angular. Sternite 4 with anterolateral margin slightly or moderately convex, moderately produced anteriorly, followed by posteriorly diminishing tubercles, posterolateral margin short, at most half as long as anterolateral margin. Anterolateral margin of sternite 5 well convex and tuberculose, about as long as posterolateral margin of sternite 4.

Abdomen: Smooth and glabrous. Somite 1 convex from anterior to posterior. Somite 2 tergite 2.1-2.4 × broader than long; pleuron anterolaterally rounded, posterolaterally bluntly angular, lateral margins strongly divergent posteriorly. Pleuron of somite 3 blunt angular posterolaterally. Telson slightly more than half (0.6) as long as broad; posterior plate 1.5-2.2 × longer than anterior plate, posterior margin distinctly emarginate.

Eye: Relatively large, 1.5 × longer than broad, proximally narrowed, overreaching midlength of, and barely reaching apex of rostrum. Cornea dilated, length more than half that of remaining eyestalk.

Antennule and antenna: Antennular ultimate article 2.0-2.5 × longer than high. Antennal peduncle reaching or slightly overreaching eyes. Article 2 with distinct distolateral spine. Antennal scale relatively slender, reaching or slightly falling short of distal end of article 5. Distal 2 articles unarmed; article 5 2.2-2.7 × longer than article 4, breadth half or less than half height of antennular ultimate article; flagellum of 13-15 (8 in male 2.7 mm) segments not reaching distal end of P1 merus.

Mxp: Mxp1 with bases close to each other or nearly contiguous. Mxp3 scarcely setose laterally. Basis with 4-7 denticles on somewhat convex, well cristate mesial ridge. Ischium with 14-20 denticles on crista dentata, flexor margin distally not rounded. Merus 2 × longer than ischium, unarmed, flexor margin not sharply crested but with rounded ridge, mesial face not flattish. No spine on carpus.

P1: With sparse long setae, very setose on fingers; scattered small tubercles on ventral surface of merus, often on carpus and palm; length 5-6 × that of carapace in both sexes. Ischium with very short distodorsal spine, ventromesial margin with or without tubercles on proximal portion or along entire length. Merus 1.1-1.2 × longer than carapace. Carpus 1.3-1.5 × longer than merus, unarmed. Palm having lateral and mesial margins subparallel, about 3 × longer than broad, slightly shorter than carpus. Fingers slightly crossing in males, not crossing in females; largely gaping in males, not gaping in females and small males; movable finger in males with strong, bifid process on gaping portion, that in female with prominent or low proximal process fitting into distinct or indistinct concavity on opposing fixed finger when closed; movable finger at most half length of palm.

P2-4: Slender and compressed mesio-laterally, with long setae on distal portions of merus, carpus and entire propodus and dactylus. Meri with smooth surface, dorsal crest with very small, often obsolescent denticles on proximal half on P2, on proximal third on P3, distally bearing fine setae; length-breadth ratio, 5.0 on P2, 4.0-5.0 on P3, 3.0-4.0 on P4;

P2 merus subequal to P3 merus in length, subequal to or slightly shorter than carapace, 1.2-1.3 × longer than P2 propodus; P4 merus much narrower than (ca. 0.6 x) P3 merus, length 0.5-0.6 × that of P3 merus, 0.8-0.9 × that of P4 propodus. P2-3 carpi subequal; P4 carpus short, 0.6-0.7 × length of P3 carpus; 0.5-0.6 × length of propodus on P2, 0.4-0.5 × on P3 and P4. Propodi longest on P3, shortest on P4, bearing long setae; flexor margin nearly straight, with pair of distal spines somewhat distant from juncture with dactylus, preceded by movable spines (6-9 in number on P2, 5-8 on P3, 4-6 on P4) along entire length to distal three-quarters of length. Dactyli rather slender, strongly or moderately curved proximally, dactylus-carpus length ratio, 0.7-0.8 on P2, 0.8-0.9 on P3, 1.0-1.1 on P4; dactylus-propodus length ratio, 0.4 on P2-3, 0.5 on P4; extensor margin often with short plumose setae on proximal two-thirds; flexor margin with 8-9 spines, distal 2 nearly terminal in position, first (ultimate) largest, other proximal spines contiguously oriented parallel to flexor margin, third (antepenultimate) rather remote from second (penultimate) and equidistant between second and fourth, occasionally closer to second, remaining spines close to one another and diminishing toward base of article.

Eggs. Up to 30 eggs carried, 1.17 mm × 1.31 mm - 1.37 mm × 1.53 mm.

Color. A Western Australian specimen was illustrated by Poore et al. (2008).

PARASITES — Rhizocephalan externae on one female from BORDAU 2 Stn CP1565 (MNHN-IU-2014-17339), one female from Stn BORDAU 2 CP1588 (MNHN-IU-2014-17340) and the female from HALIPRO 1 Stn CH 876 (MNHN- IU-2014-17346). One male from SALOMON 2 Stn CP2230 (MNHN-IU-2014-17321) is infected by a bopyrid isopod, as also are one male and two females from SALOMON 2 Stn CP2297 (MNHN-IU-2014-17324), the male from MUSORS- TOM 7 Stn CP550 (MNHN-IU-2014-17326) and the female from CP551 (MNHN-IU-2014-17327).

REMARKS — The type material of Uroptychus australis ( Henderson, 1885) now in the collection of the Natural History Museum, London, was collected from four different localities: Challenger Stn 164 off Port Jackson, Stn 194 off Banda, Stns 170 and 171 in the Kermadec Islands. Examination of the material discloses that it includes three different species. All the material (1 male, 1 ovigerous female, and 1 non-ovigerous female) from Stn 164 and part (1 male and 1 non-ovigerous female) from Station 194 are identical and referred to U. australis . Hence the lectotype was assigned to the male from Station 164 ( Baba 2005: 224). The materials from Stns 170 and 171 are identified as U. terminalis n. sp. Part of the material from Stn 194 (1 ovigerous female) is referred to U. empheres Ahyong & Poore, 2004 (see below).

The general features of the carapace and the P2-4 dactyli bearing spines oriented parallel to the flexor margin suggest that U. australis is close to U. brevirostris Van Dam, 1933 (see above) and U. setosipes Baba, 1981 , from Japan. Characters distinguishing U. australis from U. brevirostris are discussed under the remarks of U. brevirostris . Uroptychus australis has a short P4 merus, which is 0.5-0.6 times as long as the P3 merus rather than being slightly shorter as in many of the other species. Uroptychus setosipes has a short P4 merus (confirmed by examinination of the holotype), sharing with U. australis a characteristic arrangement of the anterolateral spine of the carapace situated clearly posterior to the lateral orbital spine. However, the branchial margin in U. setosipes is sharply ridged along the entire length and the antennal article 2 bears a very small instead of distinct distolateral spine, the characters to mention the obvious differences from U. australis .

The ovigerous female paratype of U. vandamae from Makassar Strait was noted to be different from both the holotype and male paratype of that species in the spination of the P2-4 dactyli ( Baba, 1988: 52). Re-examination of the types disclosed that this ovigerous paratype is referable to U. australis (see below under U. vandamae ).

The material reported under U. australis var. indicus from Zanzibar area by Tirmizi (1964) is identical to the material of U. gracilimanus from Madagascar ( Baba, 1990), but this species is different from U. gracilimanus (and U. dejouanneti n. sp.) in having the P2-4 carpi long relative to dactyli and the propodi with the different location of the flexor terminal spine, representing an undescribed species ( Baba, 2005: 36). Additional material referable to this species has been collected from the Mozambique Channel by Mainbaza Station CP3138. This species will be described elsewhere.

Figures

FIGURE 20 Uroptychus australis (Henderson,1885),types from Challenger Stn 164.A, B,lectotype,male 4.4 mm (BMNH 88:33); C-E, paralectotype, female 7.5 mm (BMNH 88:33). A, anterior part of carapace, dorsal. B, anterior part of sternal plastron. C, carapace and anterior part of abdomen, dorsal. D, anterior part of sternal plastron. E, left antenna, ventral. Scale bars:1 mm.

FIGURE 21 Uroptychus australis (Henderson,1885), paralectotype, ovigerous female 7.2 mm, from Challenger Stn 164 (BMNH 88:33). A, carapace and anterior part of abdomen,dorsal.B, same,lateral.C, excavated sternum,basal parts of Mxps 1-3 included.D, anterior part of sternal plastron. E, left antennal peduncle,ventral. Scale bars: 1 mm.

FIGURE 22 Uroptychus australis (Henderson, 1885). Detached pereopods, Challenger Stn 164 (BMNH 88:33). A, right P1, dorsal. B, left P1, dorsal.C, same,distal articles,mesial.D, left P2,lateral. E, same,distal part,mesial.F, same,dactylus,setae omitted,lateral.G, left P3, lateral.H, same,dactylus,lateral. I, right P4, lateral. J, right P2 or P3. Scale bars:A-C,5 mm;D-J,1 mm.

FIGURE 23 Uroptychus australis (Henderson, 1885). A-I, ovigerous female 7.3 mm (MNHN-IU-2014-17355). J, K, ovigerous female 7.1 mm (MNHN-IU-2014-17356). A, carapace and anterior part of abdomen, dorsal. B, same, lateral. C, sternal plastron. D, left antenna, ventral.E, left Mxp3,lateral.F, left P1, dorsal.G, left P2,lateral.H, same,distal part,lateral.I, left P3,distal part,setae omitted,lateral. J, right P3,distal part,setae omitted,lateral.K, right P4,distal part,setae omitted,lateral.Scale bars:A,B,G,F,5 mm;C-E,H-K,1 mm.