Myriotrochus hesperides O'Loughin & Manjon-Cabeza, sp. nov.

• Main Authors: O'Loughlin, Mark, Manjón-Cabeza, Eugenia, Ruiz, Francina Moya
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2009
• Subjects: Biodiversity; Taxonomy; Animalia; Echinodermata; Holothuroidea; Apodida; Myriotrochidae; Myriotrochus; Myriotrochus hesperides; Antarctic; Antarctic Peninsula; Cabeza; Gage; Antarc*
• Online Access: https://doi.org/10.5281/zenodo.6219740; http://treatment.plazi.org/id/F31587C27951FF969FDEFEBF147D164F

Myriotrochus hesperides O’Loughin & Manjón-Cabeza sp. nov. Figure 2 e, f: table 1. Material studied. Holotype. Antarctic Peninsula, BENTART–2006, R/V Hesperides , stn PA41, 65.47149ºS, 69.0285ºW, 350 m, 10 Feb 2006, MNCN 29.04/130; posterior dorsal body ossicles slide NMV F161516. Diagnosis. Specimen 13 mm long; thin translucent body wall; sub-cylindrical, dorsal oral ring projecting anteriorly over ventral, body rounded distally; 12 peltato-digitate tentacles, each tentacle with about 7 small rounded digits; plates of calcareous ring asymmetrical, with short pointed anterior projections, wide rounded tongue-like posterior projections of variable length, 2 radial plates each with 2 anterior projections. Tentacles lacking ossicles; body wall ossicles a few wheels only in the posterior dorsal body wall; wheels of one type, with teeth all pointing towards centre of hub; spokes irregular, about half branching proximally, some branches not reaching rim, some spokes with cross-connections; teeth variably sub-equal or different in size; hubs small, irregular, not disc-like, lacking perforations, formed by junction of spokes; largest wheel with diameter 248 µ m, hub diameter 40 µ m, 13 spokes at hub, 23 spokes at rim, 30 equal teeth; smallest wheel with diameter 200 µ m, hub diameter 24 µ m, 12 spokes at hub, 16 spokes at rim, 28 unequal teeth. Colour (preserved). Off-white, translucent; tentacle digit ends reddish-brown. Distribution. Antarctic Peninsula, 350 m. Etymology. Named, as a noun in apposition, for the Spanish R/V Hesperides used for BENTART–2003 and BENTART–2006. Remarks. Based on the key to the genera of family Myriotrochidae in Gage & Billett (1986), this new myriotrochid species is referred to Myriotrochus Steenstrup because it has: 12 tentacles; asymmetrical calcareous ring, with 2 radial plates each with 2 anterior projections; absence of rod ossicles; wheel hubs lacking perforations; wheel ossicles of one type only, with all teeth pointed towards centre of hub. Three specimens of myriotrochid ...