Uroptychus janiceae, Baba, Keiji & Wicksten, Mary K., 2017

Baba, Keiji & Wicksten, Mary K., 2017, Uroptychus nitidus (A. Milne-Edwards, 1880) and related species (Crustacea: Decapoda: Anomura: Chirostylidae) from the western Atlantic, Zootaxa 4221 (3), pp. 251-290 : 265-270

Uroptychus janiceae n. sp.

( Figs. 9–11 , 23 C)

Diptychus nitidus . — A. Milne-Edwards, 1880: 62 (part [Blake Sta. 130]).

Uroptychus nitidus var. B.— Chace, 1942: 15, fig. 5.— Pequegnat & Pequegnat 1970: 161.—de Melo-Filho 2006: 4.— Poupin & Corbari 2016: 38, fig. 9c.

Type material. Holotype: MCZ CRU- 11318, 1 male (CL 6.8), Nicholas Channel south of Cay Sal Bank, north coast of Cuba, 23°20’N, 80°00’W, 400 fms [732 m], 3 May 1939, Atlantis Sta. 3452.

Paratypes: MCZ CRU- 2734, 1 female (CL 5.0), off Fredericksted , St. Croix ( U. S. Virgin Islands), 17°43’00”N, 64°55’10”W, 451 fms [825 m], 4 Jan. 1879, Blake Sta. 130 . USNM 1107842 , male (CL 5.7), Gulf of Mexico , Florida, SW of Panama City, 28°07’38”N, 85°51’36”W, 624–631 m, 16 May 1985 . USNM 88691, 1 male (CL 6.0), Gulf of Mexico, off Mississippi Delta , 28°38’30”N, 87°02’W, host Acanella eburnea , 420 fms [768 m], 13 March 1885, Albatross Sta. 2394 . USNM 152481, 1 male (CL 5.7), Florida, Monroe County, Dry Tortugas, 283 fms [518 m], 0 7 July 1931, W.L. Schmitt coll . USNM 1027034, 1 male, carapace broken, northeastern Gulf of Mexico, 28°15'59"N, 86°27’51”W, 800– 770 m, 10 June 2000, DGoMB Sta. S 42 . USNM 1107846, 1 male (CL 5.9), Gulf of Mexico, off Mississippi Delta , 28°38’30”N, 87°02’W, host Acanella eburnea , 420 fms [768 m], 13 March 1885, Albatross Sta. 2394 . USNM 1107843, 4 males (CL 4.9–5.4), 7 ov. females (CL 4.3–5.7), 4 females (CL 4.8–5.4), Gulf of Mexico , Florida, SW of Panama City, 28°07’38”N, 85°51’36”W, 624–631 m, 16 May 1985 . TCWC 2-7995, 1 female (CL 5.6), southeastern Gulf of Mexico, 23°0'N, 86°48'W, 603 m, 9 July 1965, R/ V. Alaminos Sta. 65A9-15, id. L. Pequegnat (reported in Pequegnat & Pequegnat, 1970: 162) . TCWC 2-6945, 1 male (CL 6.5), 1 female (CL 5.9), southern Caribbean Sea , 11°33.8’N, 73°45.1’W, with Chrysogorgia sp. and an unidentified species of Isididae , 732 m, 17 July 1970, Alaminos Sta. 70A10-31 (identified as U. nitidus variety B by L. Pequegnat).

Description. Carapace: 1.0–[1.1] × longer than broad; greatest breadth [1.5]–1.6× distance between anterolateral spines. Dorsal surface smooth, with pair of [short granulate] or obsolescent ridges behind eyes; convex from anterior to posterior, with deep depression between gastric and cardiac regions. Lateral margins more or less denticulate, convexly slightly divergent posteriorly. Anterolateral spine relatively large, directed straight forward, overreaching small lateral orbital spine, separated from that spine by its basal breadth; branchial margin with row of short ridges (fine crenulations in dorsal view), followed by ridge along posterior third. Rostrum sharp narrow triangular, with interior angle of 13–[19]°, straight horizontal; dorsal surface nearly flattish; length 1.4– [1.5] × breadth, 0.6 × length of carapace. Lateral limit of orbit with tiny spine slightly anterior to position of anterolateral spine. Pterygostomian flap smooth on surface, anteriorly more or less roundish, ending in small spine.

Sternum: Excavated sternum sharp triangular on anterior margin, with or [without] spine in center. Sternal plastron as long as broad, sternites 4–6 successively broader posteriorly, sternites 6 and 7 subequally broad. Sternite 3 well depressed, anterior margin shallowly concave, with pair of submedian spines separated by narrow notch, anterolateral end with distinct spine. Sternite 4 anterolateral margin convex, with 5 low blunt spines on anterior half; length [1.3]–1.6 × that of posterolateral margin. Anterolateral margin of sternite 5 about as long as posterolateral margin of sternite 4.

Abdomen: Smooth and glabrous. Somite 1 with moderately rounded transverse ridge. Somite 2 tergite 2.4 × broader than long, pleuron with blunt anterolateral and posterolateral ends. Pleura of somites 3–4 laterally bluntly subtriangular. Telson 0.6 × as long as broad; posterior lobe 1.7–[2.1] × longer than anterior lobe, distinctly emarginate on posterior margin.

Eyes: 1.2–1.5 [1.4] × longer than broad, reaching midlength of rostrum, mesial margin proximal to cornea concave. Cornea barely or [feebly] dilated, slightly longer than remaining ocular peduncle.

Antennule and antenna: Ultimate article of antennule [3.2]–3.9 × longer than broad. Antennal peduncle distinctly overreaching cornea. Article 2 with distinct distolateral spine. Antennal scale 1.5–[2.0] × broader than article 5, ending in [distal third] or distal fourth of that article. Articles 4 and 5 unarmed; article 5 twice as long as article 4, breadth less than half height of ultimate article of antennule. Flagellum consisting of 16–[24] segments, slightly falling short of, reaching or [slightly overreaching] distal end of P1 merus.

Mxp: Mxp1 with bases close to each other. Mxp3 basis with 4 denticles on mesial ridge. Ischium with [17]–21 denticles on crista dentata, flexor margin not rounded distally. Merus 2.5–[2.7] × longer than ischium, flexor margin sharply ridged. No spine on merus and carpus.

P1: [5.0]–5.2 × longer than carapace, sparsely setose. Ischium with small dorsal spine, unarmed elsewhere. Merus [1.2]–1.3 × longer than carapace, feebly granulose, ventral surface with feeble groove along mesial margin. Carpus subcylindrical, feebly granulose, [1.1]–1.2 × longer than merus. Palm smooth, glabrous, [2.2]–2.7 × (males), 2.9–3.1 × (females) longer than broad, 0.8–[0.9] × length of carpus. Fingers setose, distally ending in somewhat incurved spine; in males, gaping in proximal half, opposable margins straight in distal half, movable finger with 2 processes in gaping portion, distal prominent, proximal small; in females, not gaping. Movable finger 0.8–[0.9] × length of palm.

P2–4: Slender, somewhat compressed (surface not flattish), with relatively long setae moderate in density, unarmed on meri and carpi. Meri successively shorter posteriorly (P3 merus 0.8–[0.9] × length of P2 merus, P4 merus [0.8]–0.9 ×length of P3 merus); length-breadth ratio, [7.8]–8.5 on P2, 5.8–7.4 [6.4] on P3, 4.6–5.7 [5.1] on P4; P2 merus 1.0–[1.2] × length of carapace, [1.2]–1.3 × length of P2 propodus; P3 merus 1.0–1.1 × length of P3 propodus; P4 merus 0.8 × length of P4 propodus. Carpi [subequal on P2 and P3, shorter on P4] or successively slightly shorter posteriorly; carpus-propodus length ratio, [0.5]–0.6 on P2, 0.5 on P3, 0.4–[0.5] on P4. Propodi [subequal in length] on P2–4, slightly shorter on P2 than on P3 and P4 or successively longer posteriorly; flexor margin straight, with pair of terminal spines preceded by 5 or [6] spines on P2, 5–[7] on P3, 5 on P4, all basally articulated and long. Dactyli subequal, 0.4 × length of propodus, strongly curving at proximal third; flexor margins with [8 or 9] (rarely 10) subtriangular, somewhat obliquely directed spines, ultimate slightly longer than penultimate.

Eggs: Number of eggs carried, up to 8; size, 0.88 mm × 1.04 mm – 1.29 mm × 1.45 mm).

Color: Overall deep orange, but pale on posterior two thirds of carapace and on part of abdomen ( Poupin & Corbari 2016: fig. 9c; Fig. 3 C, reproduced by permission of J. Poupin).

Host: Acanella eburnea (Pourtalès, 1868) , bamboo coral of family Isididae .

Remarks. This species is referable to U. nitidus variety B of Chace (1942) that was described based on the material from Atlantis Stations 3452, 3475, 3449, 2985 from the north coast of Cuba. One of the lots, a male from Station 3452, has been examined. The other lots are now housed in the Museum of Comparative Zoology under the registration numbers: MCZ CRU-11319 (Sta. 2985), MCZ CRU-11317 (Sta. 3449) and MCZ CRU-11316 (Sta. 3475). Chace (1942) noted that there were no representatives in the collection of the Blake material. However, among the syntypes of U. nitidus we found a female from Blake Station 130 that can be referred to this species.

This species resembles U. alphonsei n. sp. Distinguishing characters of these species are outlined under the remarks of the latter species (see above).

Uroptychus janiceae is distinguished from U. nitidus by the P1 carpus, which is cylindrical instead of well flattened; the P1 movable finger, which is slightly shorter than the full length of instead of slightly more than half the length of the palm; and the anterior margin of sternite 3,which is more shallowly excavated.

Distribution. East of St. Augustine (Florida), north coast of Cuba, northern and southeastern Gulf of Mexico, southern Caribbean, and Brazil off Paulo, 458– 808 m.

Etymology. Dedicated to the late Janice D. Chace, the wife of Fenner Chace, for her hospitality during a stay of KB in the Smithsonian Institution in 1973–74.

Figures

FIGURE 3. Uroptychus alphonsei n. sp., holotype, male (CL 5.3), MCZ CRU- 11320. A, carapace and anterior part of abdomen, dorsal; B, same lateral; C, sternal plastron, with excavated sternum, proximal part of Mxp 1 included. D, telson. E, right antenna, ventral. F, right Mxp 3, ventral, G, same, lateral. Scales = 1 mm.

FIGURE 9. Uroptychus janiceae n. sp., holotype, male (CL 6.8), MCZ CRU- 11318. A, carapace and anterior part of abdomen, dorsal. B, same, lateral. C, sternal plastron, with excavated sternum, proximal part of Mxp 1 included. D, telson. E, left antenna, ventral. F, right Mxp 3, ventral; G, same, lateral. Scales = 1 mm.

FIGURE 10. Uroptychus janiceae n. sp., holotype, male (CL 6.8), MCZ CRU- 11318, A – C, left P 1. D, E, right P 1. A, ischium, merus and carpus, dorsal, B, palm and fingers, dorsal. C, ischium and merus, ventral. D, carpus, mesial. E, palm and fingers, mesial. Scale = 1 mm.

FIGURE 11. Uroptychus janiceae n. sp., holotype, male (CL 6.8), MCZ CRU- 11318. A, left P 2, lateral. B, same, distal part, setae omitted, lateral. C, left P 3, setae omitted, lateral. D, same, distal part, lateral. E, left P 4, lateral. F, same, distal part, lateral. Scales = 1 mm.

FIGURE 23. A, Uroptychus nitidus with host corals taken in the northwestern Gulf of Mexico, 27 ° 4.8 ’ N, 92 ° 49.2 ’ W, 1145.9 m, remotely operated vehicle Deep Discoverer from R. V. Okeanos Explorer, photo courtesy of the U. S. National Oceanographic and Atmospheric Administration Office of Ocean Exploration and Research. B, U. fenneri n. sp., off Guadeloupe, KARUBENTHOS 2015 Sta. DW 4592, 214 – 201 m, MNHN-IU- 2013 - 19018. C, U. janiceae n. sp., off Guadeloupe, KARUBENTHOS 2015 Sta. CP 4618, 780 – 828 m, MNHN-IU- 2013 - 19095. D, U. uncifer, off Guadeloupe, KARUBENTHOS 2015 Sta. DW 4538, 338 – 320 m, MNHN-IU- 2013 - 18912 (Photo credits: B and C, Joseph Poupin; D, Laure Corbari).