Pseudothyone labradorensis Kremenetskaia, Alvestad, Penney, Hamel, Neves, Côté & Mercier, 2024, sp. nov.

• Main Authors: Kremenetskaia, Antonina, Alvestad, Tom, Penney, Heather D., Hamel, Jean-François, de Moura Neves, Bárbara, Côté, David, Mercier, Annie
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2024
• Subjects: Biodiversity; Taxonomy; Animalia; Echinodermata; Holothuroidea; Dendrochirotida; Sclerodactylidae; Pseudothyone; Pseudothyone labradorensis; Labrador Sea
• Online Access: https://doi.org/10.5281/zenodo.12689200

Pseudothyone labradorensis sp. nov. Figs 2, 3 Type material. Holotype . Canada • 9.5 mm in length; Labrador Sea, 56.500, - 58.084, depth 740–969 m (between bottom and recovery); 30 Aug. 2020; Station ISECOLD - 0-1000; rock dredge; substratum primarily mud with sparse rocks; IORAS ECH 02801, ID AMLAB- 02. Paratype . Canada • 14 mm in length, collected at same time and locality as holotype; IORAS ECH 02802, ID PT 1210. Both holotype and paratype are preserved and stored in 96 % ethanol. Diagnosis. Body curved, cylindrical, tapered at anterior and posterior ends. Body colour in vivo pinkish. Tentacles 10, two ventral tentacles smaller. Tube feet arranged in several rows along radii, also present in interradii and on tapered posterior part of body. Body-wall ossicles slightly concave plates of irregular shape with smooth margins and perforations. Ossicles of tube feet rod-shaped; terminal plate irregular in shape; rods not numerous, smooth, with enlarged tuberculous ends. Tentacle ossicles rods with enlarged perforated ends. Segments of calcareous ring with undivided posterior projections. Description. Body curved towards dorsal side, wider and cylindrical in the middle, anterior end tapered towards terminal mouth, posterior end tapered to a ‘ tail’ towards terminal anus, ‘ tail’ short, more prominent in paratype and short in holotype (Fig. 2 A – D). Body colour pinkish in living specimens (Fig. 2 A, B), tentacles, tube feet and ‘ tail’ more brightly coloured; colour in ethanol uniformly greyish, tentacles and tube feet whitish or greyish (Fig. 2 C, D). Body length 9.5 mm in holotype, 14 mm in paratype. Body-wall skin thin, rough, non-transparent, with dense layer of scale-like ossicles (Fig. 2 G). Tentacles (examined in holotype, in paratype they were partly retracted) ten, two ventral tentacles remarkably smaller in size. Tube feet small (Fig. 2 F), non-transparent in ethanol, arranged in several rows along radii and also scattered in interradii; tube feet more numerous on mid body, along ventrolateral and ...