Chirostylidae of the Western and Central Pacific: Uroptychus and a new genus (Crustacea: Decapoda: Anomura)
Baba, Keiji
Mémoires du Muséum national d'Histoire naturelle
2018
2018-09-30
Tropical Deep-Sea Benthos
212
1
612
223b69d8-451e-41ae-816d-cc02d69f1773
Baba, 2018
Baba
2018
[204,394,617,642]
Malacostraca
Chirostylidae
Uroptychus
Animalia
Decapoda
184
185
Arthropoda
species
dualis
sp. nov.
Figures 80, 81
TYPE MATERIAL— Holotype: New Caledonia. MUSORSTOM 4 Stn DW156, 18°54’S, 163°19’E, 530 m, 15.IX.1985, ♂ 3.4 mm( MNHN-IU-2014-16396). Paratypes: New Caledonia. MUSORSTOM 4 StnDW156, 18°54.00’S, 163°18.80E, 530 m, 15.IX.1985, 2 ♂3.0- 3.4 mm, 1 ov. ♀ 4.2 mm(MNHN-IU-2014-16397). – StnDW162, 18°35’S, 163°10’E, 535 m, 16.IX.1985, 1 ♂ 3.7 mm, 1 ov. ♀4.0 mm (MNHN-IU-2014-16398). – StnCP194, 18°52’S, 163°21’E, 550 m, 19.IX.1985, 1 ov. ♀ 4.7 mm(MNHN-IU-2014-16399), 24 ♂ 3.5-5.4 mm, 22 ov. ♀3.4-5.0 mm, 3 ♀ 3.5-3.7 mm(MNHN-IU-2014-16400). – StnDW197, 18°51’S, 163°21’E, 560 m, 20.IX.1985, 29 ♂ 2.6-5.1 mm, 19 ov. ♀ 2.7-5.1 mm, 5 ♀ 2.5-4.4 mm( MNHN-IU-2014-16401). – StnCP199, 18°51’S, 163°14’E, 600 m, 20.IX.1985, 1 ♂ 3.2 mm(MNHN-IU-2014-16402). OTHER MATERIAL EXAMINED— New Caledonia, Chesterfield Islands. MUSORSTOM 5 Stn DW355, 19°36.43’S, 158°43.41’E, 580 m, 18. X.1986, 1 ♂ 2.7 mm(MNHN-IU-2014-16404). New Caledonia. BIOCAL Stn DW38, 23°00’S, 167°15’E, 360 m, 30.VIII.1985, 1 ♂ 1.7 mm( MNHN-IU-2010-5435). – Stn DW77, 22°15’S, 167°15’E, 440 m, 5. IX.1985, 1 ov. ♀ 3.3 mm(MNHN-IU-2014-16407). New Caledonia, Isle of Pines. MU- SORSTOM 4 Stn CP216, 22°59.5’S, 167°22.0’E, 490-515 m, 29.IX.1985, 1 ov. ♀ 3.4 mm(MNHN-IU-2014-16408). – Stn DW221, 22°58.6’S, 167°36.8’E, 535-560 m, 29.IX.1985, 9 ♂ 2.5-4.2 mm, 6 ov. ♀ 2.5-3.8 mm(MNHN-IU-2014-16409). – Stn DW222, 22°57.6’S, 167°33.0’E, 410-440 m, 30.IX.1985, 1 ♂ 2.8 mm(MNHN-IU-2014-16410). BERYX 11 Stn DW27, 23°37.25’S, 167°41.20’E, 460-470 m, 18.X.1992, 9 ♂3.6-5.0 mm, 7 ov. ♀3.9-5.0 mm, 1 ♀ 3.9 mm(MNHN-IU-2014-16411). BIOCAL Stn CP52, 23°06’S, 167°47’E, 540-600 m, 31.VIII.1985, 1 ♀ 3.2 mm(MNHN-IU-2014-16412). SMIB 2 Stn DC26, 22°59’S, 167°23’E, 500-535 m, 21. IX.1986, 1 ♀ 3.2 mm(MNHN-IU-2014-16413). SMIB 3 Stn DW12, 23°42’S, 167°41’E, 470- 470 m, 22.V.1987, 2 ♂4.5, 5.0 mm, 1 ov. ♀ 4.6 mm, 1 ♀ 4.3 mm(MNHN-IU-2014-16414). – Stn DW24, 22°58.7’ S, 167°21.1’E, 535 m, 24.V.1987, 1 ♂ 4.1 mm, 1 ov. ♀ 3.6 mm(MNHN-IU-2014-16415). New Caledonia, NorfolkRidge. CHALCAL 2 Stn DW76, 23°40.5’S, 167°45.2’E, 470 m, 3.X.1986, 2 ♂4.2, 4.4 mm(MNHN-IU-2014-16416). – Stn DW77, 23°38.35’S, 167°42.68’E, 435 m, 30.X.1986, 1 ♀2.0 mm (MNHN-IU-2014-16417). BERYX 11 Stn DW38, 23°37.53’S, 167°39.42’E, 550-690 m, 19.X.1992, 2 ♂4.1, 4.8 mm, 2 ov. ♀4.9,5.0 mm (MNHN-IU-2014-16418). LITHIST Stn CP02, 23°37.1’S, 167°41.1’E, 442 m, 10.VIII.1999, 1 ov. ♀ 4.2 mm(MNHN-IU-2014-16419). – Stn CP03, 23°37.0’S, 167°41.5’E, 447 m, 10.VIII.1999, 1 ov. ♀ 4.5 mm, 1 ♀ 4.5 mm(MNHN-IU-2014-16420). NORFOLK1 Stn CP1655, 23°26’S, 167°51’E, 680 m, 19.VI.2001, 1 ♂ 3.5 mm(MNHN-IU-2014-16421). – Stn DW1659, 23°37’S, 167°41’E, 449-467 m, 20.VI.2001, 1 ♂5.0 mm, 4 ov. ♀ 3.9-4.9 mm(MNHN-IU-2014-16422). – Stn DW1662, 23°38’S, 167°42’E, 462-491 m, 20.VI.2001, 2 ov. ♀4.1, 4.4 mm(MNHN-IU-2014-16423). – Stn DW1666, 23°42’S, 167°44’E, 469-860 m, 20.VI.2001, 7 ♂ 3.8-5.2 mm, 6 ov. ♀4.0- 4.7 mm( MNHN-IU-2014-16424). – Stn DW1667, 23°40’S, 168°01’E, 237-250 m, 21.VI.2001, 1 ♂ 5.1 mm(MNHN-IU-2014-16425). – Stn CP1671, 23°41’S, 168°00’E, 320-397 m, on Chironephthyasp. ( Nidaliidae: Alcyonacea), 21.VI.2001, 1 ov. ♀ 3.7 mm(MNHN-IU-2014-16426). – Stn DW1707, 23°43’S, 168°16’E, 381-493 m, 25.VI.2001, 1 ♂4.0 mm, 2 ov. ♀4.8, 4.9 mm(MNHN-IU-2014-16427). – Stn DW1722, 23°18’S, 168°01’E, 540m, 26.VI.2001, 3 ov. ♀ 4.2- 4.7 mm, 3 ♀2.6-4.0 mm (MNHN-IU-2014-16428). – Stn DW1732, 23°21’S, 168°16’E, 347-1063 m, 27.VI.2001, 1 ♂ 3.7 mm(MNHN-IU-2014-16429). NORFOLK2 Stn DW2024, 23°27.92’S, 167°50.90’ E, 370-371 m, 21.X.2003, 2 ♂3.0, 3.2 mm, 1 ov. ♀4.0 mm, 2 ♀4.5, 4.3 mm(MNHN-IU-2014-16430). – Stn DW2031, 23°38.83’S, 167°44.01’E, 440- 440 m, 22.X.2003, 4 ov. ♀ 4.3-5.4 mm(MNHN-IU-2014-16431). – Stn DW2034, 23°40.64’S, 167°41.36’E, 485-505 m, 22.X.2003, 3 ♂ 3.4-5.4 mm, 2 ov. ♀4.2, 4.5 mm(MNHN-IU-2014-16432). – Stn DW2035, 23°39.82’S, 167°40.43’E, 515-540 m, 22.X.2003, 1 ov. ♀5.0 mm, 1 ♀ 5.3 mm(MNHN-IU-2014-16433). – Stn DW2049, 23°42.88’ S, 168°15.43’ E, 470-621 m, 24.X.2003, 1 ♂ 4.1 mm, 1 ov. ♀ 3.8 mm, 2 ♀3.2, 3.6 mm(MNHN-IU-2014-16434). – Stn DW2056, 24°40’S, 168°39’E, 573-600 m, 25.X.2003, 2 ov. ♀4.7, 4.8 mm(MNHN-IU-2014-16435). – Stn DW2132, 23°17.30’ S, 168°13.56’E, 405-455 m, 2.XI.2003, 1 ♂ 4.1 mm, 1 ♀ 2.7 mm(MNHN-IU-2014-16436). – Stn DW2136, 23°00.73’S, 168°22.68’E, 402-410 m, 3.XI.2003, 1 ♂3.0 mm, 1 ov. ♀ 3.6 mm(MNHN-IU-2014-16437). Wallis and FutunaIslands. MUSORSTOM 7 DW525, 13°11’S, 176°15’W, 500-600 m, 13.V.1992, 1 ov. ♀4.0 mm (MNHN-IU-2014-16403). Vanuatu. MUSORSTOM 8 Stn DW988, 19°16’S, 169°24’E, 372-466 m, 23.IX.1994, 1 ov. ♀ 3.3 mm, 1 ♀ 3.8 mm(MNHN-IU-2014-16405). – Stn DW1003, 18°49’S, 168°59’E, 327- 200 m, 25.IX.1994, 1 ♂ 3.7 mm(MNHN-IU-2014-16406).
ETYMOLOGY„From the Latin dualis(of two) in reference to two strong ventromesial spines on the P1 merus by which the species can be separated from U. floccus, U. quinarius,and U. lumarius, the latter three species bearing three or four spines.
DISTRIBUTION — Wallis and FutunaIslands, Chesterfield Islands, Vanuatu, New Caledonia, Isle of Pines and Norfolk Ridge; 200- 860 m. SIZE„Males, 2.5-5.4 mm; females, 2.0- 5.4 mm; ovigerous females from 2.5 mm.
DESCRIPTION„Small species. Carapace: Slightly broader than long (0.8 × as long as broad); greatest breadth 1.4 × distance between anterolateral spines. Dorsal surface slightly convex from anterior to posterior, with depression (occasionally obsolescent) suggesting cervical groove; epigastric region with transverse row of 7 or 8 small spines preceded by depressed rostrum, laterally leading to small spine dorsal to third lateral marginal spine. Lateral margins slightly convex, with 6 sharp spines: first anterolateral, well developed, extending far beyond small lateral orbital spine; second ventral to level of others, much smaller; third to sixth strong, last (sixth) followed by ridge. Rostrum sharp triangular, with interior angle of ca. 20° (18-23°), horizontal; length 0.4-0.6 × postorbital carapace length (relatively long in small specimens), breadth less than half carapace breadth measured at posterior carapace margin; lateral margin with a few very small spines distally but often obsolescent or absent; dorsal surface moderately concave. Lateral orbital spine situated directly mesial to but remote from anterolateral spine. Pterygostomian flap with anterior margin produced to strong spine; surface with a few spines small or obsolete, often well developed, situated on anterior median portion, without spine below linea anomurica between second and third lateral spines. Sternum: Excavated sternum blunt triangular between bases of Mxp1, surface with longitudinal ridge in midline. Sternal plastron somewhat broader than long, with gently divergent lateral extremities. Sternite 3 depressed well, anterior margin strongly concave, with median notch of narrow V-shape flanked by obsolescent spine, anterolateral end sharply angular, lateral margin with small spine. Sternite 4 with anterolateral margin relatively short, slightly convex, entire, with anterior end angular or produced to small spine; posterolateral margin distinctly longer than anterolateral margin. Anterolateral margin of sternite 5 anteriorly angular or rounded, about half as long as posterolateral margin of sternite 4. Abdomen: Smooth and glabrous. Somite 1 with distinct transverse ridge. Segment 2 tergite 2.6-2.8 × broader than long; pleural lateral margin weakly concave and weakly divergent posteriorly, posterolaterally rounded. Pleuron of somite 3 laterally blunt. Telson barely or fully half as long as broad; posterior plate 1.3-1.6 × longer than anterior plate, posterior margin feebly to distinctly concave. Eye: Somewhat elongate (length 1.8 × breadth), slightly overreaching midlength of rostrum, somewhat broadened proximally. Cornea not dilated, more than half as long as remaining eyestalk. Antennule and antenna: Ultimate antennular article relatively slender, 3.2-3.6 × longer than high. Antennal peduncle overreaching cornea and falling short of rostral tip. Article 2 with sharp distolateral spine. Antennal scale distinctly overreaching article 5, at least reaching second segment of flagellum, breadth about twice that of article 5. Article 4 with small, often obsolescent distomesial spine. Article 5 unarmed, 1.2-1.5 × longer than article 4, breadth 0.5-0.6 × height of ultimate antennular article. Flagellum of 11-12 segments falling short of distal end of P1 merus. Mxp: Mxp1 with bases close to each other but not contiguous. Mxp3 basis without denticles on mesial ridge. Ischium with distally rounded flexor margin; crista dentata with denticles very small, obsolescent or nearly absent. Merus and carpus each with distolateral spine; merus 2.2 × longer than ischium, mesial face flattish (slightly concave), lateral face convex, flexor margin sharply ridged, with a few spines around distal third of length. P1: More than 5 × longer than carapace (5.4-6.1 × in males, 5.7-6.0 × in females). Ischium with strong, curved, compressed distodorsal spine, and ventromesially with strong subterminal spine proximally followed by a few diminishing spines. Merus 1.3-1.5 × longer than carapace, with 2 strong mesioventral spines and very often additional 1 or 2 small or obsolete spines proximal to these, and field of 3 small spines at mesial proximal portion. Carpus 1.4-1.7 × longer than merus; distoventral spines on each side. Palm 3.5-4.2 × (males), 4.3-6.6 × (females) longer than broad, as long as or slightly longer than carpus. Fingers gaping in large specimens, more strongly so in males than in females, fitting on distal third, distally slightly incurved, crossing when closed, not spooned; movable finger with median process on gaping opposable margin, length 0.3-0.4 × that of palm. P2-4: Moderately depressed mesio-laterally, sparsely or moderately setose; meri successively shorter posteriorly (P3 merus 0.8-0.9 × length of P2 merus, P4 merus 0.8-0.9 × length of P3 merus), ventrolateral margin with small terminal spine, dorsal margin unarmed; length-breadth ratio, 4.0-5.3 on P2, 3.6-4.5 on P3, 3.0-3.3 on P4; P2 merus nearly as long as or slightly shorter than carapace, 1.2-1.5 × longer than P2 propodus, slightly more slender than P3-4 meri; P3 merus subequal to length of P3 propodus; P4 merus 0.8 × length of P4 propodus, as broad as P3 merus. Carpi subequal on P2-4, or slightly shorter on P2 than on P3-4; each distinctly less than half length of propodus (carpus-propodus length ratio, 0.34-0.36 on P2, 0.30-0.35 on P3, 0.29-0.33 on P4); extensor margin with small terminal spine distinct on P2, occasionally obsolete on P3, absent on P3. Propodi successively longer posteriorly, flexor margin nearly straight in lateral view, ending in pair of spines (placed at distal end) preceded by 6 spines on P2, 3-4 on P3, 2-3 on P4, at most on distal half of length. Dactyli successively longer posteriorly, more slender and more setose on P2 than on P3 and P4; much longer than carpi (dactylus-carpus length ratio, 1.5 on P2, 1.7 on P3, 1.8 on P4), and 0.5-0.6 × as long as propodi on P2-4; flexor margin straight, with 17-20 closely arranged, obliquely directed, short spines, penultimate about twice as broad as antepenultimate, ultimate more slender and longer than antepenultimate, all obscured by thick setae on P2. Eggs.Number of eggs carried up to 16; size, 1.08 mm× 1.17 mm- 1.40 mm× 1.20 mm. PARASITES— One of the females from NORFOLK 2, Stn DW2024 (MNHN-IU-2014-16430) bears a rhizocephalan externa.
REMARKS— This species is common around New Caledoniaand the Norfolk Ridge. The new species is grouped together with U. floccus n. sp., U. lumarius n. sp., and U. quinarius n. sp.(see below) by having a field of three closely arranged spines on the mesioproximal face of P1 merus. The spination of the carapace and P2-4 dactyli and the shape of the antenna displayed by U. dualisare very much like those of U. floccus n. sp.The relationships with these congeners are discussed under the remarks of the respective species (see below).
2603206171
1985-09-15
Stn DW
New Caledonia
530
-18.9
New Caledonia
1273
163.31667
184
185
MNHN-IU-2014-16396
1
1
holotype
2603206238
1985-09-15
New Caledonia
530
-18.9
Stn
13
163.31334
184
185
3
1
2
paratype
2603206209
1985-09-16
New Caledonia
535
-18.583334
Stn
1275
163.16667
184
185
2
1
1
paratype
2603206350
1985-09-19
New Caledonia
550
-18.866667
Stn
1273
163.35
184
185
29
5
24
paratype
2603206237
1985-09-20
MNHN-
New Caledonia
560
-18.85
Stn
1273
163.35
184
185
35
6
29
paratype
2603206215
[372,1276,931,956]
1985-09-20
New Caledonia
600
-18.85
Stn
1273
163.23334
184
185
1
1
paratype
2603206122
1986-10-18
New Caledonia
-19.607166
158.7235
184
185
1
1
2603206197
1985-08-30
MNHN-
New Caledonia
-23.0
167.25
184
185
1
1
2603206297
[306,1093,1063,1086]
1985-09-05
New Caledonia
-22.25
167.25
184
185
1
1
2603206506
1985-09-29
New Caledonia
-22.991667
167.36667
184
185
1
1
2603206094
1985-09-29
New Caledonia
-22.976667
167.61333
184
185
10
1
9
2603205946
1985-09-30
New Caledonia
-22.96
167.55
184
185
1
1
2603206279
1992-10-18
New Caledonia
-23.620832
167.68666
184
185
10
1
9
2603206184
[496,1336,1191,1214]
1985-08-31
New Caledonia
-23.1
167.78334
184
185
1
1
2603206285
1986-09-21
New Caledonia
-22.983334
167.38333
184
185
1
1
2603206479
1987-05-null
New Caledonia
-23.7
167.68333
184
185
3
1
2
2603206262
1987-05-24
New Caledonia
-22.978333
167.35167
184
185
2
1
1
2603206157
1986-10-03
New Caledonia
-23.675
167.75333
184
185
2
2
2603206278
[453,1223,1319,1342]
1986-10-30
New Caledonia
-23.639166
167.71133
184
185
1
1
2603206239
1992-10-19
New Caledonia
-23.6255
167.657
184
185
3
1
2
2603206324
1999-08-10
New Caledonia
-23.618334
167.685
184
185
1
1
2603206395
1999-08-10
New Caledonia
-23.616667
167.69167
184
185
1
1
2603206219
[383,1205,1415,1438]
2001-06-19
Norfolk Island
-23.433332
167.85
184
185
1
1
2603206191
2001-06-20
Norfolk Island
-23.616667
167.68333
184
185
2
1
1
2603206322
2001-06-20
Norfolk Island
-23.633333
167.7
184
185
1
1
2603206377
2001-06-20
MNHN-
Norfolk Island
-23.7
167.73334
184
185
8
1
7
2603206072
[315,1121,1511,1534]
2001-06-21
Norfolk Island
-23.666666
168.01666
184
185
1
1
2603206388
2001-06-21
Norfolk Island
-23.683332
168.0
184
185
1
1
Nidaliidae
2603206286
2001-06-25
Norfolk Island
-23.716667
168.26666
184
185
2
1
1
Nidaliidae
2603206256
2001-06-26
Norfolk Island
-23.3
168.01666
184
185
1
1
Nidaliidae
2603206182
[598,1403,1607,1630]
2001-06-27
Norfolk Island
-23.35
168.26666
184
185
1
1
Nidaliidae
2603206257
[174,1403,1639,1662]
2003-10-21
Norfolk Island
-23.465334
167.84833
184
185
3
1
2
Nidaliidae
2603206369
[174,1069,1671,1694]
2003-10-22
Norfolk Island
-23.647167
167.7335
184
185
1
1
Nidaliidae
2603206071
2003-10-22
Norfolk Island
-23.677334
167.68933
184
185
4
1
3
Nidaliidae
2603206173
2003-10-22
Norfolk Island
-23.663666
167.67383
184
185
1
1
Nidaliidae
2603206212
2003-10-24
Norfolk Island
-23.714666
168.25717
184
185
2
1
1
Nidaliidae
2603206252
[507,1354,1767,1790]
2003-10-25
Norfolk Island
-24.666666
168.65
184
185
1
1
Nidaliidae
2603206243
2003-11-02
Norfolk Island
-23.288334
168.226
184
185
2
1
1
Nidaliidae
2603206306
2003-11-03
Norfolk Island
186
187
-23.012167
168.378
184
185
2
1
1
Nidaliidae
2603206175
1992-05-13
Wallis and Futuna
-13.183333
-176.25
186
187
1
1
Nidaliidae
2603206156
1994-09-23
Vanuatu
-19.266666
169.4
186
187
1
1
Nidaliidae
2603206391
[609,1396,293,315]
1994-09-25
Vanuatu
-18.816668
168.98334
186
187
1
1
Nidaliidae