Munidopsis pyrochela, Ahyong, 2014

Ahyong, Shane T., 2014, Deep-sea Squat Lobsters of the Munidopsis serricornis Complex in the Indo-West Pacific, with Descriptions of Six New Species (Crustacea: Decapoda: Munidopsidae), Records of the Australian Museum (Rec. Aust. Mus.) 66 (3), pp. 197-216 : 207-209

Munidopsis pyrochela sp. nov.

Figs 6 , 9

Munidopsis sp.— O’Shea et al., 1999: 51, fig. 27; Poore et al., 2011, pl. 23F.

Munidopsis serricornis . —Baba & Poore, 2002: 241–244, figs. 6 A, B, 7A, 8A, 9A, B [part]; Ahyong & Poore, 2004: 46 , 57; Poore, 2004: 235, 237, fig. 65g; Yaldwyn & Webber, 2011: 214.

Munidopsis cf. serricornis .— Webber et al., 2010: 226; Taylor et al., 2010: 15; Rowden et al., 2011: 73.

Type material. (Chatham Rise, New Zealand). HOLOTYPE: NIWA 67818 , male (cl 13.0 mm, pcl 9.3 mm), Ritchie Seamount, E Chatham Rise, 44°10.0–10.1' S 174°34.4 –35.7'W, 836–1100 m, orange roughy trawl , TRIP 2551 /82, sample 1, in crevice in glass sponge ( Farrea similaris Reiswig & Kelly ), 18 December 2007 . PARATYPES: NIWA 53274 , 1 male (cl 7.2 mm, pcl 4.9 mm), 42°38.66–38.67' S 179°52.88 –53.05'W, 1052–1080 m, Mummy Seamount , RV Tangaroa, TAN 0905/48, 18 June 2009 ; NIWA 67819 , 1 male (cl 15.0 mm, pcl 10.9 mm), 2 females (cl 11.9–15.3 mm, pcl 8.7–11.3 mm), Mummy Seamount , 42°38.69'S 179°53.01'W, 1052–1080 m , RV Tangaroa, TAN 0905/48, 18 June 2009 ; NIWA 19203 , 2 ovigerous females (cl 16.6–20.0 mm, pcl 11.8–14.6 mm), Zombie Seamount, 42°45.91–45.79' S 179°55.62 –55.83'E, 990–1058 m, epibenthic sled , RV Tangaroa, TAN 0104/198, 19 April 2001 ; NIWA 19205 , 1 male (pcl 13.7 mm), 1 female (cl 19.3 mm, pcl 14.0 mm), Zombie Seamount, 42°45.99–46.08' S 179°55.36 –55.18'W, 970– 900 m, epibenthic sled , RV Tangaroa, TAN 0104/337, 20 April 2001 ; NIWA 19204 , 1 male (cl 15.3 mm, pcl 11.3 mm), 1 female (cl 11.4 mm, pcl 8.1 mm), Diabolical Seamount, 42°47.16–46.96' S 179°59.12 –59.01'W, 993– 900 m, epibenthic sled , RV Tangaroa, TAN 0104/48, 16 April 2001 ; NIWA 19206 , 2 females (cl 15.3–16.5 mm, pcl 11.2–12.2 mm), Diabolical Seamount, 42°47.16–46.96' S 179°59.12 –59.01'W, 993– 900 m, epibenthic sled , RV Tangaroa, TAN 0104/48, 16 April 2001 ; NIWA 19207 , 1 male (cl 12.5 mm, pcl 8.9 mm), 1 female (cl 16.0 mm, pcl 11.3 mm), Diabolical Seamount, 42°47.56–47.70' S 179°58.86 –58.60'W, 950– 900 m, epibenthic sled , RV Tangaroa, TAN 0104/47, 16 April 2001 ; NIWA 67820 , 1 male (cl 7.6 mm, pcl 5.4 mm), Voodoo Seamount, 42°44.74–44.61' S 179°55.41 –55.11'W, 1051–1129 m , RV Tangaroa, TAN 0905/42, 18 June 2009 ; NIWA 19200 , 1 female (cl 27.1 mm, pcl 19.9 mm), Chatham Rise, 43°26.7'S 173°30.0'E, 392 m, S0181, dredge, 31 Oct 1979 ; NIWA 53916 , 1 male (cl 15.5 mm, pcl 11.2 mm), 1 ovigerous female (cl 15.9 mm, pcl 11.6 mm), 1 female (pcl 9.8 mm), Ritchie Seamount , 44°10.61'S 174°33.56'W, 760–960 m, with sponge , RV Tangaroa, TAN 0905/107, 26 June 2009 .

Other material examined.— Southern Kermadec Ridge, New Zealand: NIWA 64816 , 1 male (cl 14.7 mm, pcl 10.9 mm), Rumble II West Seamount, 35°21.18'S 178°30.65'E, 1382–1416 m, TAN1007/106, epibenthic sled, 6 June 2010 ; NIWA 72432 , 1 male (cl 13.5 mm, pcl 9.6 mm), Rumble II West Seamount, 35°21.42–21.62' S 178°30.95 –31.09'E, 1387–1420 m, TAN1104/40, epibenthic sled, ES20, 8 March 2011 ; NIWA 72277 , 1 male (cl 13.6 mm, pcl 9.5 mm), 1 ovigerous female (cl 15.6 mm, pcl 11.0 mm), Clark Seamount , 36°29.04–28.93' S 177°53.24 –53.10'E, 1328– 1272 m, TAN1104/20, epibenthic sled, ES10, 3 March 2011 ; NIWA 72926 , 1 damaged male (cl ~ 19.3 mm, pcl ~ 14.3 mm), Lillie Seamount , 35°51.44–51.41' S 178°26.88 –26.55'E, 1237–1460 m, TAN1104/124, epibenthic sled, ES59, 19 March 2011 ; NIWA 72879 , 1 female (cl 17.5 mm, pcl 13.2 mm), Lillie Seamount , 35°51.65–51.39' S 178°26.90 –26.67'E, 1251–1478 m, TAN1104/123, epibenthic sled, ES57, 19 March 2011 . Chatham Rise, New Zealand: NIWA 24570 , 2 males (cl 12.3–18.2 mm, pcl 8.3–12.8 mm), 3 females (cl 17.2–18.4 mm, pcl 12.5–13.6 mm), 42°45'S 179°56'W, 927–1030 m, AMA0501/011, 20 June 2005 . The Snares, New Zealand: NIWA 19199 , 4 ovigerous females (cl 14.5–19.1 mm, pcl 10.3–14.6 mm), 48°02.01'S 166°06.01'E, 935 m , TRIP 1171 /12, Z9583, J. Wills, 25 November 1998 . Macquarie Ridge, Southern Ocean : NIWA 39722 , 1 male (cl 19.1 mm, pcl 13.6 mm), 50°05.43–05.31' S 163°28.92 – 28.32'E, 1077–1408 m , RV Tangaroa, TAN 0803/33, 1077– 1408 m, 1 April 2008 . Tasmania , Australia : NIWA 19208 , 1 female (cl 10.5 mm, pcl 7.6 mm) , South Tasman Rise , Southern Ocean, 47°09.000'S 148°43.038'E, 936 m, Z9236, 15 August 1998 ; AM P61819, 2 males (cl 13.7–20.4 mm, pcl 10.0– 15.4 mm), 2 females (cl 14.2–22.2 mm, pcl 10.5–16.3 mm), off St. Patricks Head , Tasmania, 41°35'S 148°14'E, 1100 m, trawl, FRV Soela, S 05/87/15, K. Graham, 12 July 1987 ; NMV J58233 , 1 ovigerous female (cl 23.6 mm, pcl 17.0 mm), Hill Z16 site, 44°17'32"S 147°04'01"E to 44°17'40"S 147°03'54"E, 1100–1300 m, epibenthic sled, coll . T. O’Hara & T. Costa , 2 April 2007 ; NMV J58240 , 1 male (cl 13.9 mm, pcl 9.7 mm), 1 female (damaged, cl~11.0 mm), Hill Z15 site, 44°13'54"S 147°28'22"E to 44°14'07"S 147°28'03"E, 1100–1350 m, epibenthic sled, coll . T. O’Hara & T. Costa , 3April 2007 ; NMV J44746 , 1 male (cl 15.4 mm,pcl 11.2 mm), “U” seamount, 82.8 km SSE of South East Cape, 44°19.20'S 147°07.20'E, 1083 m, trapline,FRV Southern Surveyor , stn SS1/97-41, coll . T.N. Stranks et al., 27 January 1997 . Southwest Indian Ridge, Indian Ocean : AM P92563, 1 ovigerous female (cl 14.3 mm, pcl 10.2 mm), Middle of What Seamount , 37°56.795'S 50°27.240'E, 1414 m, RRS James Cook cruise JC066, ROV Keel 6000, 12 February 2011 ; OUMNH. ZC.2013-01-008, 1 male (cl 16.6 mm, pcl 12.6 mm), Middle of What Seamount , 37°56.795'S 50°27.240'E, 1414 m, RRS James Cook cruise JC066, ROV Keel 6000, 12 February 2011 .

Diagnosis. Rostrum broad, flat, medially carinate, trifid distally. Carapace with pair of epigastric spines, otherwise unarmed dorsally; surface of dorsal half with faint short striae; lateral margins with 4 spines (1 anterolateral, 3 branchial); posterior orbital margin transverse; outer orbital spine distinct. Abdominal tergites unarmed. Telson with 8 plates. Maxilliped 3 merus flexor margin with 2 or 3 spines. Cheliped carpus length less than twice width, dorsal surface unarmed; merus with 3 longitudinal rows of prominent spines (dorsal, mesial, ventromesial). Walking leg meri distinctly spinose along extensor margin; dactylus flexor margin with movable spines, and more slender movable spine at base of corneous unguis. Pereopods without epipods.

Description. Carapace: Moderately convex from side to side; covered with short, fine setae; surface of anterior half smooth, with few scattered, fine short striae; surface of posterior half with fine distinct striae. Cervical groove indistinct. Pair of epigastric spines. Posterior orbital margins transverse to slightly oblique, outer orbital spine prominent. Frontal margins oblique; anterolateral spine similar to outer orbital spine. Lateral margins broadly convex; with 2 spines on anterior branchial margin and spine (bifid on left side of holotype) at junction of anterior and posterior branchial margins. Rostrum broad, 0.4 pcl; trifid distally; apex slightly deflected dorsally; median carina distinct; lateral proximal margin convex. Posterior margin unarmed, medially concave. Pterygostomian flap with short diagonal striae; anterior margin blunt, angular.

Sternum: Sternite 3 about one-fourth width of sternite 4. Posterior margin of sternite 3 contiguous with anterior margin of sternite 4. Sternites smooth, sparsely setose, unarmed.

Abdomen: Tergites with short, fine, scattered setae, unarmed. Tergites 2–4 with elevated anterior ridge; tergites 2 and 3 also with shallow groove behind anterior ridge. Tergites 4 and 5 with shallow, medially interrupted, transverse groove. Tergite 6 smooth; posterior margin not strongly produced. Telson composed of 8 plates (minute central plate present); lateral margin of midlateral plate lined with coarse, relatively stiff setae in males, distally setose in females. Uropodal endopod lateral margins setose, unarmed.

Eye: Ocular peduncle unarmed, dorsally setose; movable; partially concealed by rostrum. Cornea subglobular, slightly wider than peduncle. Small, slender spine adjacent to lateral margin of eye.

Antennule: Basal article squat, with 2 distolateral spines, dorsal shorter; distomesial margin with short triangular tooth.

Antenna: Basal article with triangular mesial and lateral tooth, neither overreaching article 2. Article 2 with strong distolateral spine, reaching beyond midlength but not apex of article 3. Article 3 with distomesial spine. Article 4 with lateral triangular projection. Flagellum slightly shorter than carapace length.

Maxilliped 3: Dactylus, propodus and carpus unarmed. Merus extensor margin with 2 small, blunt to acute tubercles and distal spine; flexor margin with 2 large triangular spines proximally and 1 or 2 smaller spines distally. Ischium longer than wide, with distal flexor and extensor spine.

Pereopod 1 (cheliped): Elongate, 2.2–2.9 pcl (males), 2.0–3.0 pcl (females); with tufts of long, simple golden setae, most numerous on mesial and lateral margins; subcylindrical to ovate. Ischium with ventrodistal spine and dorsal spine. Merus with row of 6–8 strong, graded dorsal spines, largest distally; mesial margin with 2 large mesial spines, one distally at carpal articulation, one slightly distal to midlength of margin; ventromesial margin with 1–3 (usually 2) strong spines proximally and distal spine. Carpus 1.5–1.7 times longer than wide; mesial margin with distal and subdistal spine, latter largest; distodorsal and distoventral spine. Propodus unarmed, palm 2.0–2.5 times as long as wide; mesial margin of palm longer than dactylus. Pollex and dactylus occlusal margins crenulated, apices with interlocking teeth; pollex occlusal margin with low tooth at midlength; dactylus occlusal margin with 2 or 3 proximal teeth. Epipod absent.

Pereopods 2–4: Slightly compressed; decreasing in length posteriorly; with scattered, setose striae. Merus elongate; length about 3.1–3.9 times width (pereopod 2) to 2.4–3.1 (pereopod 4); extensor margin with prominent upright spines (pereopods 2 and 3) or serrated (pereopod 4); distal extensor margin with large distal spine; flexor margin irregular to serrated but not spinose except for strong distal spine. Carpus with distal extensor spine and irregular or serrated margin (occasionally spinular on pereopods 2 and 3); with low, irregular, dorsal carina. Propodus extensor margin irregular, unarmed; flexor margin with movable spine at distal one-third to one-fourth and paired movable spines distally adjacent to dactylar articulation. Dactylus about twothirds propodus length; extensor margin with scattered setae, unarmed; flexor margin with 9–11 low triangular teeth, each bearing corneous movable spine and more slender movable spine at base of corneous unguis. Epipods absent.

Egg diameter: 1.6–1.8 mm.

Colour in life. Carapace and abdomen off-white; lateral margins and ridges with pale orange-brown marks. Chelipeds deep orange-red. Walking legs off-white. Cornea pale pink. The holotype is depicted in colour by Poore et al. (2011, pl. 23F).

Etymology. Derived from the Latin pyro, fire and chela, alluding to the orange-red chelipeds of the new species.

Remarks. Most previous records of M. serricornis from southeastern Australia are based on M. pyrochela sp. nov. (see Baba & Poore, 2002; Ahyong & Poore, 2004). Munidopsis pyrochela is readily distinguished from M. serricornis , however, by the presence of epigastric spines on the carapace and the colour in life, in which the carapace and walking legs are whitish rather than orange. Of the serricornis -complex species, M. pyrochela sp. nov. most closely resembles those having a pair of epigastric spines and spinose extensor margins of the walking legs, namely M. spiridonovi sp. nov., M. mina Benedict, 1902 from the eastern Pacific, and two western Atlantic species, M. tridens (A. Milne-Edwards, 1880) and M. transtridens Pequegnat & Pequegnat, 1971 .

Munidopsis pyrochela differs from M. transtridens in the less slender cheliped carpus with a length less than twice the width (versus about 2.5–3 times width). From M. mina , M. pyrochela is readily distinguished by the presence of a prominent spine on the mesial margin of the carpus of the cheliped in addition to a small distal spine adjacent to the propodal articulation, rather than only a small distal spine. From M. tridens , M. pyrochela differs in having eight rather than seven telson plates, and three instead of two longitudinal rows of spines on the merus of the cheliped.

The presence of epigastric and lateral carapace spines is remarkably consistent in M. pyrochela , being present in all specimens including the smallest specimen examined (male, pcl 4.9 mm, NIWA 53274). The larger western Indian Ocean specimen (male, pcl 12.6 mm, OUMNH.ZC.2013-01- 008) initially appeared to lack epigastric spines, but close inspection revealed that the spines were broken. Australian and New Zealand specimens usually have an irregular or serrated extensor carpal margin on the walking legs, but on pereopods 2 and 3, up to three of these serrations may be developed as spines, as in the two western Indian Ocean specimens. A specimen from The Snares (NIWA 19199) and a western Indian Ocean specimen (AM P92563) are the smallest ovigerous females at pcl 10.3 mm and pcl 10.2 mm, respectively.

The strongly disjunct distribution of M. pyrochela , between southern Australia and the western Indian Ocean, is conspicuous. The level of sampling from intermediate localities in the southern Indian Ocean, however, is presently inadequate to determine if the disjunction is real or artefactual. Material from both regions are similar, the two western Indian Ocean specimens being less setose dorsally than the Australian and New Zealand examples; the significance of these differences requires further study, especially given the apparent distributional disjunction. A similar disjunction applies also to the deep-water caridean shrimp, Leontocaris bulga Taylor & Poore , which is known from Tasmania and off southeast Africa (Komai & Chan, 2010).

Munidopsis pyrochela is a common seamount species and the most southerly occurring species of the serricornis complex, ranging into Subantarctic waters. The typical habitat of M. pyrochela remains to be confirmed, although the holotype was collected from a crevice in a hexactinellid glass sponge Farrea similaris Reiswig & Kelly , and other specimens were collected together with various other species of hexactinellids. Munidopsis pyrochela has not yet been confirmed from deepwater corals, unlike M. serricornis , which is a known associate of the arborescent Lophelia pertusa in the northern Atlantic ( Lavaleye et al., 2009).

Distribution. Southwest Indian Ridge (Middle of What Seamount), New Zealand and south-eastern Australia, ranging in the east from the southern Kermadec Ridge and The Snares, south to the Macquarie Ridge and westwards to Tasmania including the South Tasman Rise and Cascade Plateau; 392–1414, usually 900–1000 m.

Figures

Figure 6. Munidopsis pyrochela sp. nov., male holotype, cl 13.0 mm, pcl 9.3 mm (NIWA 67818). (A) dorsal habitus; (B) carapace, right lateral view; (C) right antenna and antennules, ventral view; (D) right basal antennular article, lateral view; (E) right maxilliped 3; (F) right crista dentata;(G) right cheliped finger tips, ventral view; (H) right cheliped ischiomerus, lateral view;(I) sternal plastron;(J) telson. Scale:A, B, G–I = 2.0 mm; C–F, J = 1.0 mm.