Sigmodota magnibacula Massin & Heterier 2004

• Main Authors: O'Loughlin, P. Mark, Mackenzie, Melanie, Vandenspiegel, Didier, Griffiths, Huw
• Format: Other/Unknown Material
• Language: unknown
• Published: 2015
• Subjects: Biodiversity; Taxonomy; Animalia; Echinodermata; Holothuroidea; Apodida; Chiridotidae; Sigmodota; Sigmodota magnibacula; Weddell; Weddell Sea; Antarc*; Antarctica
• Online Access: https://zenodo.org/record/6096654; https://doi.org/10.5281/zenodo.6096654

Sigmodota magnibacula (Massin & Hétérier, 2004) Figure 1, 5, key Taeniogyrus contortus.— Ekman, 1927: 416 –417.— Cherbonnier, 1974: 610.— Gutt, 1988: 24.— Gutt, 1991: 324. (all or part probably non Taeniogyrus contortus (Ludwig, 1875)) Taeniogyrus cf. contortus.— O’Loughlin et al., 1994: 553, 554. Taeniogyrus magnibaculus Massin & Hétérier, 2004: 441 –444, figs 1, 2, table 1. Sigmodota magnibacula.— O’Loughlin & VandenSpiegel, 2010: 82, 84, figs 1 e, 11, tables 2, 3. Material examined. Antarctica, Weddell Sea, station ‘Shelf Canyon 2 ’, AGT 39, 76.161694– 76.16887 ºS, 27.79659– 27.79802 ºW, agassiz trawl 549.28–555.26 m, BAS cruise JR 275 RSS James Clark Ross, collected by M. Mackenzie et al., 21 /02/ 2012, NHMUK 2014.31 (1). Description. Sigmodotid species specimen, vermiform, tapered posteriorly (posterior end missing), 15 mm long (preserved); scattered dorsal, lateral and ventral wheel-cluster papillae; 12 tentacles, seven pairs of digits, largest distally; single polian vesicle. Ossicles in tentacles rods, some with short distally-spinous or handle-like branches along shafts, short bluntly spinous bifurcations distally, rods 205–256 µ m long; ossicles in body wall wheels and sigmoid hooks; wheels clustered into discrete papillae dorsally and laterally and ventrally, wheels rounded hexagonal with six spokes and continuous series of teeth around inner rim, diameters up to 80–117 µ m; sigmoid hooks scattered throughout body wall, fine spinelets on distal outer end, hook lengths 122–151 µ m. Colour. Alcohol-preserved (briefly): body and tentacle and oral disc completely covered with fine “black” speckle over off-white. Distribution. Antarctica, Weddell Sea, ‘Shelf Canyon’, 76 ºS, 28 ºW, 549– 555 m. Remarks. As noted in earlier remarks, it is evident from Table 3 in O’Loughlin & VandenSpiegel (2010) that for specimens of Sigmodota magnibacula the sizes of the wheel and sigmoid hook and tentacle rods ossicles increase significantly with increasing specimen size. The size ranges of tentacle rods, ...