Uroptychus naso ( Van Dam, 1933 )

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 : 335-336

Uroptychus naso ( Van Dam, 1933)

Uroptychus naso Van Dam, 1933: 23 , figs 35-37. — Van Dam 1939: 402 (part); 1940: 97. — Baba 1969: 42 (part), fig. 2a; 1988: 39. — Wu et al. 1998:

81, figs 5, 12B. — Baba 2005: 49. — Baba et al. 2008: 37, fig. 1F. — Baba et al. 2009: 47 (part), figs 38, 40. — Poore & Andreakis 2011: 158, figs

4a, 5a, 6, 7.

TYPE MATERIAL — Syntypes: Indonesia, Kur Island and Taam Island, Kai Islands , 204-304 m, 2 males from SIBOGA Stn 253, 304 m ( ZMA De. 101.692 ) ; 1 male and 1 female syntype from SIBOGA Stn 251, 204 m ( ZMA De. 101.667). [not examined].

MATERIAL EXAMINED — Indonesia, Kai Islands. KARUBAR Stn CP05, 05°49’S, 132°18’E, 296-299 m, 22.X.1991, 2 ♂ 7.3, 7.3 mm ( MNHN- IU-2014-16793) . – Stn CP16, 5°17’S, 132°50’E, 315-349 m, 24.X.1991, 1 ♂ 7.2 mm (MNHN-IU-2014-16794). Indonesia, Tanimbar Islands. KARUBAR Stn CP82, 9°32’S, 131°02’E, 219- 215 m, 4.XI.1991, 2 ♂ 6.9, 7.2 mm, 2 ov. ♀ 7.1, 7.7 mm, 1 ♀ 5.2 mm (MNHN-IU-2014-16795) . – Stn CP86, 9°26’S, 131°13’E, 225- 223 m, 4.XI.1991, 3 ♂ 7.8-9.1 mm, 2 ov. ♀ 6.6, 8.5 mm, 2 ♀ 8.0, 8.3 mm (MNHN-IU-2014-16796). Philippines. MUSORSTOM 1 Stn CP03, 14°01’N, 120°15’E, 183-185 m, 19.III.1976, 19.III.1976, 1 ov. ♀ 8.2 mm (MNHN-IU-2014-16797) . – Stn CP35, 14°08’N, 120°17’E, 186-187 m, 23.III.1976, 1 ♂ 11.8 mm, 2 ov. ♀ 7.7, 8.3 mm (MNHN-IU-2014-16798). – Stn CP36, 14°00’N, 120°17’E, 210- 187 m, 23.III.1976, 1 ♂ 3.2 mm ( MNHN- IU-2014-16799). MUSORSTOM 2 Stn CP01, 14°00’N, 120°18’E, 198- 188 m, 20.XI.1980, 1 ♂ 11.3 mm, 1 ♀ 6.5 mm (MNHN-IU-2014-16800) .– Stn CP19, 14°00.5’N, 120°16.5’E, 189-192 m, 22.XI.1980, 1 ov. ♀ 10.9 mm (MNHN-IU-2014-16801). – Stn CP53, 14°01’N, 120°17’E, 215-216 m, 27.XI.1980, 3 ♂ 6.4-8.7 mm (MNHN-IU-2014-16802) . – Stn CP54, 14°00’N, 120°10’E, 170-174 m, 27.XI.1980, 1 ov. ♀ 11.0 mm (MNHN-IU-2014-16803).

DISTRIBUTION„ Southern Japan, East China Sea, Taiwan, Philippines, Indonesia, and northern Western Australia; 128- 440 m. Poore & Andreakis (2011) believed that the material reported by Van Dam (1940) from Java Sea can be referred to this species. It was taken in 68- 71 m.

SIZE„ Males 3.2-11.8 mm; females, 5.2-11.0 mm; ovigerous females from 6.6 mm.

DIAGNOSIS — Medium-sized to large species. Carapace 0.9-1.2 × as long as broad; greatest breadth 1.8-2.0 × distance between anterolateral spines. Dorsal surface covered with tubercles, bearing a few to several small spines on hepatic region; deep cervical groove bordering gastric and cardiac regions, and anterior and posterior branchial regions, anterior cervical groove indistinct. Lateral margins divergent posteriorly; anterolateral spine small but distinctly overreaching lateral orbital spine, followed by a few small spines on hepatic region and relatively large spines on branchial region (anterior branchial margin with 2 spines, posterior smaller than anterior, often followed by much smaller spine; posterior branchial margin with 7 or 8 spines relatively widely spaced anteriorly). Rostrum broad, long triangular, with interior angle of 30-33°, somewhat deflected ventrally or nearly horizontal; dorsally covered with tubercles and depressed in midline, laterally with 6-8 small spines on anterior half, proximalmost spine located slightly to greatly proximal to midlength (at most to point one-third from proximal end); length 0.7-0.8 × (longer in young specimens) that of carapace, breadth slightly more than half carapace breadth at posterior carapace margin. Pterygostomian flap covered with small spines, anteriorly angular, produced to strong spine. Excavated sternum anteriorly ending in convex margin, surface with longitudinal ridge in midline. Sternal plastron 1.1-1.2 × longer than broad, lateral extremities somewhat divergent posteriorly; sternite 3 moderately depressed; anterior margin shallowly excavated, bearing deep U-shaped median sinus flanked by small or obsolescent spine; anterolateral margin of sternite 4 denticulate, occasionally with distinct terminal spine, nearly straight, 1.1-1.3 × longer than posterolateral margin. Anterolateral margin of sternite 5 subequal to or shorter than posterolateral margin of sternite 4. Abdominal somite 1 with transverse ridge; somite 2 tergite 2.2-2.4 × broader than long, pleural lateral margin moderately concave, slightly divergent posteriorly; pleuron of somite 3 laterally blunt. Telson 0.4 × as long as broad; posterior plate distinctly emarginate on posterior margin, length 1.3 × that of anterior plate. Eyes short, ending in proximal third of rostrum. Ultimate anten-

nular article 3 × longer than high. Antennal peduncle having distal 2 articles each mesially with distoventral spine; article 5 1.4-1.6 × as long as article 4, breadth 0.6 × height of antennule ultimate article; antennal scale barely reaching apex of article 5, often with 1 or 2 small lateral spines proximally; flagellum of 9-10 segments very short, about as long as distal 2 articles combined. Mxp1 with bases strongly produced mesially, hence close to each other but somewhat separated. Mxp3 basis with 4 or 5 obsolescent denticles; ischium having flexor margin distally ending in spine laterally accompanying a few small spines, crista dentata with very small, obsolescent denticles; merus 1.7-1.9 × longer than ischium, flattish on mesial face, with distinct distolateral spine, flexor margin with a few distinct spines distal to midlength; carpus with distinct distolateral spine and small spines on lateral face. P1 depressed distally, especially palm and fingers, covered with spinules and scattered short setae, bearing spines along mesial and lateral margins, mesial spines larger; ischium with strong dorsal spine laterally and dorsally accompanying small spines, ventromesial margin with strong subterminal spine often followed by small spines; merus 1.1-1.3 × longer than carapace; carpus 1.0-1.2 × as long as merus; palm as long as carpus; fingers broad relative to length, slightly incurved distally, movable finger with 1 blunt tooth on opposable margin, occasionally with 2 teeth in males, length 0.4-0.5 (longer in small specimens) that of palm. P2-4 broad relative to length, bearing fine setae much longer than those on P1; meri successively shorter posteriorly (P3 merus 0.9 × length of P2 merus, P4 merus 0.8 × length of P3 merus), equally broad on P2-4; lengthbreadth ratio, 3.1-3.5 on P2, 2.8-3.0 on P3, 2.3-2.5 on P4; P2 merus 0.8-0.9 × length of carapace, 1.4-1.6 × length of P2 propodus; P3 merus 1.3 × length of P3 propodus; P4 merus 0.9-1.0 × length of P4 propodus; meri covered with denticles on lateral surface, mesial face flattish, dorsal margin sharply ridged bearing row of sharp spines continued on to carpus, distal portion of ventrolateral margin with several spines as equally sharp as but larger than those on extensor margin, terminal spine strongest; carpi subequal on P2-3, shorter on P4, each less than half (0.4) length of propodus on P2-4; propodi successively longer posteriorly or slightly shorter on P2 than on P3-4; flexor margin straight, with pair of distal spines preceded by smaller spines (4-10 on P2, 3-8 on P3, 3-6 on P4; fewer in small specimens), some of these on P2 and P 3 in zigzag arrangement along midline; lateral and mesial faces with no dense tufts of short setae on P2-4; dactyli short relative to breadth, less than half as long as propodi, dactylus-carpus length ratio, 0.7-0.8 on P2, 0.8-0.9 on P3, 0.9-1.0 on P4; flexor margin slightly convex distally, with row of 9-11 somewhat inclined spines, penultimate 2 × broader than antepenultimate, remaining spines slender, ultimate slightly broader and distinctly longer than antepenultimate.

Eggs. Number of eggs carried up to 60; size, 1.46 × 1.32 mm (largest) in diameter.

Color. Illustrated by Poore & Andreakis (2011: fig. 4a).

PARASITES — The smaller female from MUSORSTOM 2 Stn CP51 (MNHN-IU-2014-16860) bears a rhizocephalan externa.

REMARKS — Poore & Andreakis (2011) reviewed the naso complex based on morphological and molecular data, describing two new species: U. cyrano from northern Western Australia and U. pinocchio from the Philippines, Taiwan and Japan. These two species have dense tufts of short setae on P2 and two longitudinal bands on the carapace, the clear differences from U. naso . Some of the features that they believed to characterize U. naso as different from these congeners are not exactly applicable: the rostrum that is said to be deflected ventrally is often horizontal in the present material. An additional character distinguishing U. naso from the two congeners is that the sternal plastron is shorter relative to breadth, the length-breadth ratio, 1.1-1.2 versus 1.4. The coloration is also clearly different between U. naso and U. pinocchio , as shown by Poore & Andreakis (2011).