Munidopsis livida ( Perrier, 1886 )

Macpherson, Enrique & Segonzac, Michel, 2005, Species of the genus Munidopsis (Crustacea, Decapoda, Galatheidae) from the deep Atlantic Ocean, including cold-seep and hydrothermal vent areas, Zootaxa 1095 (1), pp. 1-60 : 34-35

Munidopsis livida ( Perrier, 1886) ( Fig. 9 )

Elasmonotus lividus Perrier, 1886 : fig. 242.

Orophorhynchus lividus .—A. Milne Edwards & Bouvier, 1894: 287, fig. 12; 1900: 343, pl. 4: fig. 3, pl. 31: figs 17–22.

Munidopsis lividus — Doflein & Balss, 1913: 178 (list).

Munidopsis livida — Miyake & Baba, 1970: 94.— Pequegnat & Pequegnat, 1971: 19, fig. 12.—Udekem d’Acoz, 1999: 167.

Material examined. Off Congo, M56, Stn GeoB 8215­2, TV­grab, 06º11.04’S, 10º25.53’E, 2417 m, 21.12.2002: 1 ovig. female 10.7 mm. Off Angola, BIOZAIRE 3, Stn CP 20, 05°46.89'S, 09°44.66'E, 3113 m, 02.01.2004: 2 males 9.7–14.6 mm, 3 ovig. females 15.1–20.0 mm, 2 females 10.5–12.3 mm. Diagnosis. Carapace surface unarmed, nearly devoid of setae. Frontal margin oblique lateral to eyestalks; lateral border convex, cristate, overhanging pterygostomian flap. Rostrum very broadly triangular, about one­third as long as remaining carapace, constricted between eyes, horizontal, dorsal carina continued onto anterior gastric region; lateral margin finely serrate. Third sternite with two anterior lobes; fourth sternite narrowly elongate anteriorly, lateral margins concave. Abdominal somites unarmed; posterolateral lobes of somites 6 distinct but not overreaching somewhat convex transverse posteromedian margin. Telson divided into 8 plates, posterior plates combined more than twice as wide as long. Ocular peduncles slightly movable, eyestalks produced anteriorly beyond cornea; cornea moderately small. Antennal peduncle having article 1 with anteriorly produced spine ventrally, dorsolateral margin broadly produced; article 2

sometimes with distolateral spine, article 3 distolaterally produced, with small distomesial spine. Merus of third maxilliped with small denticular spines of irregular sizes on flexor margin, extensor distal margin with small, acute spine. Chelipeds granulate, spineless, relatively stout, short, about as long as postorbital carapace length; fixed finger with denticulate carina on distolateral margin. First walking legs longer than chelipeds; merus somewhat cristate along extensor margin; extensor margin of carpus cristate; propodus with weak granulate ridge along lateral surface; dactylus ending in curved claw preceded by 13 proximally diminishing spines on nearly straight flexor margin, each spine bearing short seta. Epipods present on chelipeds. Egg diameter 1.8 mm

Remarks. Munidopsis livida belongs to the group of species having the dorsal surface of the carapace and abdomen unarmed, the rostrum wide and carinated dorsally, the main eyespine situated on the mesial end of the eyestalk, the fixed finger of the cheliped with denticulate carina on the distolateral margin, the first walking leg overreaching the end of the cheliped, and epipods present on the chelipeds. The closest species of the genus are M. ceratophthalma Alcock, 1901 from the Andaman Sea and West of Sumatra, between 677 and 878 m ( Alcock 1901, Doflein & Balss 1913), M. edwardsii Wood­Mason, 1891 from the Bay of Bengal and New South Wales, Australia, between 1379 and 2610 m (Wood­ Mason 1891, Alcock 1901, Baba & Poore 2002, Baba 2005), and M. profunda Baba, 2005 from the Celebes Sea, between 5163 and 5243 m ( Baba 2005). However, the three species can be easily be distinguished from M. livida by the following characters:

– The shape of the rostrum is different. Munido psis ceratophthalma , M. edwardsii and

M. profunda have a triangular rostrum, not covering the eyes, whereas in M. livida the

rostrum is wide, nearly covering the eyes.

– The dorsal margins of merus and carpus of the walking legs have some spines in M.

ceratophthalma, M. edwardsii and M. profunda , whereas these spines are absent in M.

livida.

– The epipods on the chelipeds are present in M. livida , M. edwardsi and M. profunda ,

whereas they are absent in M. ceratophthalma . Additionally, M. edwardsii has two

epigastric processes, that are absent in M. livida , M. ceratophthalma and M. profunda .

Distribution and habitat. Munidopsis livida was described from two specimens (one male and one ovigerous female) collected off the Canary Islands at 2115 m (A. Milne Edwards & Bouvier 1894). The species was subsequently recorded from the Gulf of Mexico, between 2070 and 2790 m ( Pequegnat & Pequegnat 1971). The present material extends the known range to the central eastern Atlantic (off Congo).

The M 56 specimen was collected with a TV grab at Congo Fan , about 90 km south of the cold­seep site Regab. The photographs taken around the location of the capture show that the faunal community is similar to that of Regab site, except that mytilid bivalves are apparently absent .

Figures

FIGURE 9. Munidopsis livida (Perrier, 1886), ovigerous female (10.7 mm), off Congo, M56, Stn GeoB 8215­ 2. A, carapace, dorsal. B, same, lateral. C, posterior part of sixth abdominal segment and telson. D, sternal plastron. E, right antennule, antenna and ocular peduncle, ventral. F, endopod of right third maxilliped, setae omitted, lateral. G, left cheliped, lateral. H, left second pereiopod, lateral. I, dactylus of left second pereiopod, lateral. Scale: 1 mm.