Munida isos Ahyong & Poore, 2004

Ahyong, Shane T., Schnabel, Kareen E. & Baba, Keiji, 2015, Southern High Latitude Squat Lobsters: Galatheoidea and Chirostyloidea from Macquarie Ridge with Description of a New Species of Uroptychus, Records of the Australian Museum 67 (4), pp. 109-128 : 122-124

Munida isos Ahyong & Poore, 2004

Fig. 8

Munida isos Ahyong & Poore, 2004b:34 , fig. 6 (type locality: off St. Patricks Head, Tasmania, 41°35'S, 148°14'E, 1100 m). — Poore, 2004: 234, fig. 64d (compilation). — Baba, 2005: 265 (key, synonymies). — Ahyong, 2007: 31 . — Baba et al., 2008: 102 (synonymies).

Munida microps . — Haig, 1973: 273 (part, smaller specimen only). — Davie, 2002: 65 (in part, no record).

Munida gordoni Vereshchaka, 2005: 139 , fig. 2 (type locality: New Zealand, 41°35.45'S, 175°46.39'E, 1000–1400 m).

Material examined. Macquarie Ridge: NIWA 39597 , 2 females (pcl 7.2, 11.1 mm), 2 males (pcl 7.0, 7.3 mm), Spastic Spider Seamount, 48°31.90'S, 164°56.84'E, 1060–1112 m, 30 March 2008 , TAN0803/19; NIWA 99730 , 1 ov. female (cl 13.3, pcl 9.0 mm), Seamount 1, Spastic Spider, 48°33.03'S, 164°57.07'E, 1067 m, Z9586, 13 December 1998 ; NIWA 39574 , 1 ov. female (pcl 6.1 mm), 1 female (pcl 7.1 mm), 2 males (pcl 5.5, 7.3 mm) Spastic Spider Seamount, 48°32.92'S, 164°57.75'E, 1318–1327 m, 30 March 2008 , TAN0803/17; NIWA 39762 , 10 males (cl 7.6, pcl 4.8 to cl 18.4, pcl 12.3 mm), 6 ov. females (cl 12.3, pcl 8.2 to cl 14.4, pcl 10.2 mm), 10 females (cl 9.2, pcl 6.4 to cl 13.5, pcl 9.1 mm, largest with epicaridean), Clementsville Seamount, 50° 05.429 –05.320 'S, 163° 28.930 –28.330 'E, 1077–1408 m, 01 April 2008 , TAN0803/33; NIWA 39791 , 1 ov. females (pcl 9.3 mm), 1 female (pcl 8.4 mm), 2 males (pcl 5.2 mm, one damaged), Clementsville Seamount, 50°05.920'S, 163°29.10'E, 1144.0– 1365 m, 01 April 2008 , TAN0803/36; NIWA 39983 , 3 ov. females (pcl 10.1–12.1 mm), 2 males (pcl 7.5 mm, one damaged), Eltanin Seamount, 51°02.590'S, 161°58.85'E, 560– 506 m, 04 April 2008 , TAN0803/52; NIWA 39916 , 1 female (pcl 9.0 mm), Eltanin Seamount, 51°05.73'S, 161°58.58'E, 462–524 m, 04 April 2008 , TAN0803/48; AM P97852, 3 ov. females (pcl 10.5–12.1 mm), 4 females (pcl 8.2–12.5 mm), 4 males (pcl 7.0– 11.6 mm), Seamount 7 (Australian EEZ), 53°42.91'S, 159°07.830'E, 770–810 m, 12 April 2008 , TAN0803/79; AM P97854, 3 ov. females (pcl 12.1, 15.1 mm, one damaged), 2 males (pcl 10.1, 10.5 mm), Seamount 8, Macquarie Ridge (Australian EEZ), 55°21.19'S, 158°26.20'E, 605–709 m, 15 April 2008 , TAN0803/93; AM P97853, 1 ov. female (damaged, pcl ~ 14.5 mm), Seamount 8 (Australian EEZ), 55°22.87'S, 158°25.59'E, 504–637 m, 15 April 2008 , TAN0803/89.

Christable Seamount: NIWA 46521 , 17 females (pcl 7.6–15.1 mm), 2 females (pcl 10.8, 9.3 mm), 8 males (pcl 10.0– 11.9 mm), 51°03.20'S, 164°36.43'E, 990– 973 m, 14 April 2003, TAN0306/5 ; NIWA 76192 , 1 male (cl 21.1, pcl 14.6 mm), 51°03.20'S, 164°36.43'E, 990– 973 m, 14 April 2003, TAN0306/5 ; NIWA 46519 , 1 male (pcl 10.8 m), 51°03.88'S, 164°35.27'E, 968–973 m, 14 April 2003, TAN0306/8 ; NIWA 10934 , 10 ov. females (pcl 7.5–12.4 mm), 7 females (pcl 5.6–9.3 mm), 13 males (6.2–12.2 mm), 51°04.32'S, 164°36.36'E, 1065– 1030 m, 14 April 2003, TAN0306/7 ; NIWA 46522 , 8 ov. females (pcl 8.4–12.1 mm), 4 females (pcl 6.2–8.6 mm), 9 males (pcl 9.6–12.9 mm, one damaged), 50°56.30'S, 164°33.16'E, 1053– 998 m, 14 April 2003, TAN0306/4 ; NIWA 46520 , 14 ov. females (pcl 8.3–13.5 mm), 5 females (pcl 6.6–10.5 mm), 11 males (pcl 5.8–12.9 mm), 50°56.56'S, 164°36.55'E, 1140– 1105 m, 14 April 2003, TAN0306/6 ; NIWA 46523 , 1 ov. female (pcl 10.0 mm), 2 females (pcl 9.7, 11.0 mm), 4 males (pcl 6.9–11.3 mm), 50°56.56'S, 164°36.55'E, 1140– 1105 m, 14 April 2003, TAN0306/6 .

Diagnosis. Carapace with long, scattered setae; transverse striae widely spaced, often intervened by short striae or scales; with transverse row of 6 or 7 epigastric spines; with numerous granules on anterolateral region; with or without postcervical spine. Rostrum spiniform. Supraocular spines divergent. Margins of carapace with 5 spines posterior to cervical groove. Thoracic sternite 4 at most with few short striae; sternites 5–7 smooth. Abdominal tergite 2 with row of 6–9 (usually 6) spines on anterior border; remaining tergites unarmed. Eye with cornea dilated, maximum diameter about one-quarter distance between anterolateral spines. Basal antennular article overreaching cornea; with 2 terminal spines, mesial shorter; ventral surface unarmed. Basal antennal article with strong mesial spine; article 2 with short mesial and lateral terminal spines, neither overreaching article 3; article 3 with or without small lateral spine. Maxilliped 3 ischium with distal flexor spine; merus flexor distal spine about half length of proximal spine, occasionally with small spine on margin between distal and proximal spines. P1 slender, length 2–3 × cl (about 3–4 × pcl); pollex without spines on outer margin. P2–3 meri with spinose extensor and flexor margins. P4 extensor and flexor margins with distal spine. P2–4 dactyli with movable spines distributed along entire flexor margin and slender corneous seta at base of unguis. (Modified after Ahyong & Poore, 2004b).

Remarks. Munida isos is the most abundant seamount squat lobster around New Zealand ( Rowden et al., 2010). Material examined from Macquarie Ridge and Christable seamounts accords well with material described by Ahyong & Poore (2004b) from southeastern Australia. Size and number of epigastric and hepatic carapace spines and tubercles varies with body size, with large specimens having the most pronounced ornamentation. The outer margin of antennal article 3 (described as unarmed by Ahyong & Poore, 2004b) is usually unarmed ( Fig. 9J ) in the present series but may have a small spine in larger specimens ( Fig. 9B ). Postcervical spines are generally absent in M. isos , noted present in nine specimens (female, pcl 6.2 mm, NIWA 46522; male, pcl 11.1 mm, NIWA 10934; 6 females pcl 6.5–8.3 mm, NIWA 39762; male pcl 14.6 mm, NIWA 76192, Fig. 9A ). Of the specimens from NIWA 76192 with postcervical spines, the spine is present on the left side only in the 6.5 mm female, and as a double spine on the right side of the 6.8 mm female.

Rhizocephalan externae are present under the abdomen of specimens from five lots (NIWA 10934, 39597, 46520, 46521, 45523) and epicaridean parasites are present in specimens from six lots (NIWA 10934, 39597, 39762, 46522, 46523).

Distribution. Known from eastern Australia (from east of Broken Bay, New South Wales, south to Tasmania) and widespread around New Zealand (from the Kermadec Ridge, Bay of Plenty, East Cape Ridge, Hikurangi Margin, Chatham Rise, off Fiordland), Solander Trough, and Macquarie Ridge; typical seamount species, 462–2756 m.

Figures

Figure 8. Munida isos Ahyong & Poore, 2004. (A–H) male pcl 14.6 mm, Christable Seamount (NIWA 76192). (I–J) ov. female pcl 8.3 mm, Clementsville Seamount (NIWA 39762). (A) carapace and abdomen. (B) right antenna and antennule, ventral. (C) right maxilliped 3. (D) right P1 (setae omitted). (E–G) right P2–4 (setae omitted). (H) sternal plastron. (I) right maxilliped 3 merus. (J) right antenna, ventral. Scale:A, D–G = 4.0 mm; B, C, H = 2.0 mm; I–J = 1.0 mm.

Figure 9. New Zealand region showing the Macquarie Ridge (¡) and Christable (¡ c) seamounts, and sampling