Molpadiodemas epibiotus, O'Loughlin & Ahearn, 2005

O'Loughlin, P. Mark & Ahearn, Cynthia, 2005, A review of pygal-furrowed Synallactidae (Echinodermata: Holothuroidea), with new species from the Antarctic, Atlantic and Pacific oceans, Memoirs of Museum Victoria 62 (2), pp. 147-179 : 159-160

Molpadiodemas epibiotus sp. nov.

Figures 3i–k , 4m –p

Material examined. Holotype. North Atlantic Ocean , Caribbean Sea, Cuba, Cayman Trench, 19°39'N, 76°17'W, 6195–6320 m, RV Gilliss, stn GS-121, 21 Jul 1975, USNM 1008183 .

Paratypes. Type locality and date, USNM 1008310 (4) ; NMV

F101862 (1).

Description. Up to 125 mm long; body strongly tapered posteriorly, dorsoventrally depressed, low convex dorsally, flat ventrally; thin brim anteriorly around mouth, variably developed laterally, posteriorly; all specimens with anterior large concave depression suggesting epibiote attachment, some smaller depressions mid-body; body wall firm, thin, soft, semi-gelatinous, embedded with white granules, surface wrinkled, additionally pustulose ventrally; complete cover of small tube feet, translucent and merged into body wall dorsally; lateroventral tube feet in widely spaced band, sparse, subglobular, up to 0.5 mm long, 0.25 mm diameter, some with dark red markings; ventral tube feet closer, smaller, some with red markings, not extended, 0.2 mm diameter as domes; ossicles in tentacles only, abundant, variable, rods, thick to thin, lumpy to smooth to bluntly spinous, with or lacking swelling in mid-rod, limited branching at ends, some branches fused to create perforations, ossicles up to 300 Μm long.

Colour. Dorsally off-white to greyish-white; ventrally reddish-brown around mouth, dark red flecking on surface and on some tube feet.

Etymology. From the Greek epi (upon) and bios (life), referring to the evidence for epibiotic attachments on all specimens.

Distribution. North Atlantic Ocean, Caribbean Sea, Cayman Trench, 6195–6320 m,

Remarks. Amongst Molpadiodemas species, the distinguishing characters of M. epibiotus are: distinctly posteriorly tapered body; dorsoventral depression of the body; presence of a thin brim anteriorly; presence of anterior concavities from epibiotes; fine dark red markings ventrally on the body surface and tube feet.

Figures

Figure 3. a–b, M. atlanticus (NMV F101845, 210 mm long); a, ventral view; b, small epibiotes on body wall. c–e, M. constrictus sp. nov. (USNM 1022815, paratypes); c, dorsal view (51 mm long); d, ventral view (51 mm long); e, tube feet. f–g, M. crinitus sp. nov. (USNM 1023615, holotype, 96 mm long); f, ventral view; g, ventrolateral tube feet. h, M. depressus, pygal furrow, gelatinous body, lateral brim (NMV F101849). i–k, M. epibiotus sp. nov. (USNM 1008183, holotype, 110 mm long); i, ventral view, posterior taper; j, ventral mouth, epibiote concavities (arrows); k, ventral view, epibiote concavity (left arrow), few tube feet (central arrow). l, M. helios sp. nov., tentacle digits, tube feet (lower right) (USNM E31104, paratype). m–o, M. involutus (NMV F101850, 40 mm long); m, ventral view, serrated margin; n, dorsal anterior view, globigerines attached; o, posterior ventrolateral tube feet.

Figure 4. Tentacle ossicles (SEM). a–d, Meseres atlanticus, a–c (USNM E49466), d (USNM 1020067). e–h, M. crinitus sp. nov. (USNM E48662). i–l, M. depressus (USNM E53279). m–p, M. epibiotus sp. nov. (USNM 1008310, paratype). q–t, M. helios sp. nov., q–r (USNM E31104, paratype), s–t (USNM E31117, paratype). u–x, M. involutus (USNM E49256).