Munidopsis Whiteaves, 1874

Schnabel, Kareen E. & Bruce, Niel L., 2006, New records of Munidopsis (Crustacea: Anomura: Galatheidae) from New Zealand with description of two new species from a seamount and underwater canyon, Zootaxa 1172, pp. 49-67 : 51-55

Genus Munidopsis Whiteaves, 1874

See Baba (2005) for full synonymy, diagnosis and species list for Indo­Pacific species. Remarks

Presently, 122 species of Munidopsis are known in the Indo­Pacific region ( Baba 2005), which is somewhat higher than in the Atlantic where 70 species are currently known (including those species that occur in multiple oceanic basins). Recent monographic accounts are Ahyong & Poore (2004) on the eastern Australian fauna (reporting two known species and adding four new species) and Baba’s (2005) Galathea report (describing 10 new Indo­Pacific species including one from New Zealand). The prevalence of Munidopsis as a conspicuous element at hydrothermal vents and cold seeps has stimulated two recent publications providing valuable information on aspects of the biology and biogeography of this genus. Macpherson & Segonzac (2005) documented 22 species of deep­sea Munidopsis from vent and seep habitats across the Atlantic Ocean, and Martin & Haney (2005) recently presented a review of 125 species of decapods from hydrothermal vents and cold seeps worldwide, which included 11 species of Munidopsis from sites in the North Atlantic, Gulf of Mexico, Indo­West Pacific and East Pacific.

Munidopsis kaiyoae Baba, 1974

( Fig 2 )

Munidopsis kaiyoae Baba, 1974: 390 , figs. 8, 9.— Khodkina, 1981: 1263.— Baba, 2005: 282 (key), 290 (list). Type locality: Off the east coast of South Island, New Zealand, 44°20.50’S, 179°17.50’W, 750 m.

Material examined

1 ♀ (paratype, 20 mm), Chatham Rise , east of South Island, 44°20.50’S, 179°17.50W, 15 July 1968, 750 m, Kaiyo Maru stn 33 ( NMNZ CR.1925) . 1 ♀ (ovig. 22 mm), Pukaki Rise , south of South Island, 48°45.00’S, 172°0.00’E, 20 January 1965, 658 m, stn. F107 ( NIWA 19176 ) . 1 ♂ (14 mm), Challenger Plateau , west of North Island, 37°30.47’S, 168°35.24’E, 22 March 2002, 966 m, stn. Z11036 ( NIWA 19177 ) . 1 ♂ (26 mm), off Otago , South Island, 45°12.10’S, 171°43.59’E, 11 October 1965, 594 m, stn. E413 ( NIWA 19178 ) . 1 ♀ (28 mm), Hikurangi Trough , off south of North Island, 41°40.41’S, 175°15.24’E, 30 March 1967, 618 m, stn. E752 ( NIWA 19179 ) . 1 ♂ (18 mm), Challenger Plateau , west of North Island, 38°38.60’S, 172°37.59’E, 28 March 1968, 691 m, stn. E906 ( NIWA 19180 ) . 1 ♂ (17 mm), Chatham Rise , 44°15.0’S, 175°25.59’E, 17 August 1966, 594 m, stn. F750, ( NIWA 19181 ) . 1 ovig. ♀ (17 mm), Challenger Plateau , 40°46.00’S, 167°54.54’E, 18 April 1980, 1029 m, stn. P928 ( NIWA 19182 ) . 2 ovig ♀♀ (18 mm, 21 mm), Challenger Plateau , P942 ( NIWA 19183 ) . 1 ♂ (15 mm), Challenger Plateau , 41°0.36’S, 169°5.60’E, 24 April 1980, 914 m, stn. P942 ( NIWA 19186 ) . 1 ♂ (20 mm), Bay of Plenty , east of North Island, 37°32.33’S, 176°48.36’E, 18 January 1998, 550 m, stn. KAH9801/5 ( NIWA 19184 ) . 1 ♂ (16 mm), Raukumara Plain , east of North Island, 38°46.00’S, 178°48.00’E, 23 March 1967, 913 m, stn. E719 ( NIWA 19185 ) . 1 ♂ (8 mm), Chatham Rise , 44°19.18’S, 173°35.30’E, 28 October 1979, 525 m, stn. S159 ( NIWA 19187 ) . 1 ♂ (18 mm), Hikurangi Trough , 42°1.48’S, 174°26.30’E, 30 March 1967, 885 m, stn. E756 ( NIWA 19188 ) . 1 ♀ (16 mm), Pukaki Rise , 50°0.00’S, 170°0.00’E, 20 February 1970, 608 m, stn. H55 ( NIWA 19189 ) . 1 ♀ (23 mm), Hikurangi Plauteau , off East Cape, North Island, 37°19.30’S, 178°10.59’E, 0 3 October 1968, 1050 m, stn. F873 ( NIWA 19190 ) . 1 ♂ (15 mm), North Taranaki Bight , off west of North Island, 37°19.59’S, 173°56.60’E, 24 March 1968, 728 m, stn. E894 ( NIWA 19191 ) . 1 ♂ (16 mm), Pukaki Rise , 48°31.59’S, 168°54.29’E, 18 January 1965, 706 m, stn. F99 ( NIWA 19192 ) .

Remarks

All specimens can be confidently identified from the description given by Baba (1974) based on three females from one location on the Chatham Rise. The new material examined includes seven females and ten males from 16 locations ( Fig. 1 ). There is some variation in spination of the gastric and cardiac regions and of the posterior margin of the dorsal carapace as indicated by Baba (1974). A single specimen from the North Taranaki Bight (NIWA 19191) has a small mesogastric spine behind the typical epigastric, protogastric and cardiac spines.

In all but one specimen (NIWA 19182), the distomesial margin on the antennule is produced to an acute spine preceded by a row of tubercles. Baba (1974) illustrated the antennule of the holotype with a slightly produced margin with a few tubercles. Paratype CR.1925, however, examined here, had an acute spine similar to that found more commonly in the material examined. Therefore, the antennule is figured from the female paratype ( Fig. 2 ).

Cheliped length is sexually dimorphic, with male chelipeds generally longer than female chelipeds (1.54–2.65 times as long as carapace, including rostrum, measured from tip of the dactylus to the proximal end of the merus), and in females chelipeds are 1.17–1.65 [female paratype = 1.55] times as long as the carapace, including rostrum.

Distribution

Munidopsis kaiyoae is thought to be a New Zealand endemic, previously known from two stations on the Chatham Rise. The distribution is extended geographically to the north and east and it is now known to occur across the New Zealand continental shelf and slope between 37° and 50°S ( Fig. 1 ). Its depth range is extended from the currently known 720–750 m to 525–1050 m.

Munidopsis marginata ( Henderson, 1885)

Elasmonotus marginatus Henderson, 1885: 416 ; 1888: 161, pl. 19: figs. 2, 2a.— Thomson, 1899: 196 (list).

Munidopsis marginata .— Döflein & Balss, 1913: 176 (list).— Baba & Poore, 2002: 237, fig. 4.— Baba, 2005: 280 (key), 291 (list).

Type locality. East of southern North Island, New Zealand, 40°28’S, 177° 43’E, 2013 m .

Material examined

1 ♂ (17 mm), Young Nick’s seamount, Hikurangi Plateau, 39°27.11’S, 179°57.44’E, 19 November 2004, 2308– 2207 m, stn. TAN0413/193 ( NIWA 9025 ) . 1 ♀ (19 mm), Young Nick’s seamount, Hikurangi Plateau, 39°27.29’S, 179°55.29’E, 20 November 2004, 2127– 2130 m, stn. TAN0413/201 ( NIWA 9026 ) .

Remarks

Both specimens conform well to the illustrations of Henderson (1888) and Baba & Poore (2002). New Zealand material shares the rudimentary epigastric processes with the illustrated specimen of Baba & Poore (2002), whereas Henderson’s (1888) figure shows small but more distinct epigastric spines, a character that is often variable in species of Munidopsis . A slight variation in the female (NIWA 9026) is a more acute distolateral spine on each of the first antennal segments than illustrated by Baba & Poore (2002). The male (NIWA 9025) has a more blunt lateral process on the first antennal article as previously illustrated. The largest New Zealand specimen (cl = 19 mm) is slightly larger than the Australian specimen (cl = 15.3 mm) and smaller than the female Challenger specimen (cl = 36.5 mm). Measurements for the second and smaller female specimen described by Henderson (1885) are only given for the full body (35 mm), which is comparable to the present material (36 mm ♀ and 30 mm ♂ full body length).

Distribution

Previously known from the northeastern coast of New Zealand (Hikurangi Trough) and southeastern Australia ( Fig. 1 ). The present records are from a seamount within 100 km of the type locality. Baba (2005) reported a bathymetric range of 1750–2013 m. The present records extend the known depth range to 2308 m.

Figures

FIGURE 1. Station records of the currently known species of Munidopsis (solid symbols) and new records (open symbols) around New Zealand. 250 m and 2000 m bathymetric contours are shown.

FIGURE 2. Munidopsis kaiyoae Baba 1974, paratype, ♀, NMNZ CR. 1925, right antennule, ventral. Scale: 2 mm.