Bathyplotes sp.

Mackenzie, Melanie, Davey, Niki, Burghardt, Ingo & Haines, Margaret L., 2024, A report of sea cucumbers collected on the first dedicated deep-sea biological survey of Australia’s Indian Ocean Territories around Christmas and Cocos (Keeling) Islands (Echinodermata: Holothuroidea), Memoirs of Museum Victoria (Mem. Mus. Vic.) 83, pp. 207-316 : 277-279

publication ID	https://doi.org/10.24199/j.mmv.2024.83.03
publication LSID	urn:lsid:zoobank.org:pub:9065254A-A8EE-4162-ACDE-4D7F01B4A213
persistent identifier	https://treatment.plazi.org/id/432A0A53-5232-FFFE-FC93-ED9FFEA5F934
treatment provided by	Felipe
scientific name	Bathyplotes sp.
status

Treatment

Bathyplotes sp. MoV. 7340

Material examined. NMV F308259 About NMV * (2), [IN 2022 V 08 141] , NMV F308261 About NMV * (1) and NMV F308266 About NMV *(4) [IN 2022 V 08 143] , NMV F308304 About NMV * (1) [IN 2022 V 08 157] .

Diagnosis of IOT material. Specimens all damaged with few external features remaining. Light pink and semitranslucent, gelatinous, elongate, dorsoventrally flattened to cylindrical, and typically covered in grit, up to ~ 14 cm long, 3.5 cm wide ( NMV F308266 About NMV , pre-preservation). Specimens likely elongate and dorsoventrally flattened when live, but often just central vermiform section remaining here. No tube feet or papillae remaining, although potential canals visible in semitranslucent lateral skin. Anus terminal. Mouth ventral to terminal. Tentacles lost from most specimens, approximately 18 non-retractable light orange tentacles visible in NMV F308304 About NMV with prominent black dots (eye spots?) on many. Discs with indented edges look molar-shaped when preserved, black spots remain. Ossicles include spinous rods, occasional Cs, and some or all of the following Bathyplotes- type tables ,

Type 1) Tables with medium height four-pillared spires viewed from top as highly spinous/thorny central square (occasionally joining) with four long, smooth, slightly curved arms, perforated at ends, often with one or more larger perforations and sharp edges or spines starting to branch.

Type 2) Tables with tall four-pillared spires, distally spinous only (not along spire), with four or five crossbeams on slight angle and base made from four short, perforated arms joined to form a perforated button-disc. Differs from type 1) by shorter, joined arms.

Type 3) Tables with short, thick, four-pillared spires, typically with only one or two crossbeams at top, spires from tapered to almost mace-shaped, irregularly spinous along length of spire.

Remarks. Table type 2) is closest to the type illustration of Bathyplotes natans (M. Sars, 1868) , only differing in that the original illustrations show no complete discs, but four short arms starting to join, while IOT specimens were often completely joined. Table type 3) matches additional B. natans photographs from SolÍs-MarÍn (2003) of synonymised B. bipartitus type slides. Rods, Cs and Type 3 tables also show some similarities to B. sulcatus original type illustrations (Sluiter, 1901) and subsequent (quite different) illustrations by Heding (1940), though Type 2 joined bases are shown. Specimens do not match the photographed form of B. natans from type location ( SolÍs-MarÍn, 2003), and no conspicuous furrow or tube feet are available to check against B. sulcatus body form. Given the mixed known characters between species and the distinct square spire tops of Type 1 tables here, here we identify specimens to Bathyplotes sp. MoV. 7340.

Distribution. These specimen lots only: Indian Ocean, Australian IOT, Cocos (Keeling) Islands Territory, Cocos (Keeling) Stn. and Muirfield Seamount Stn., 1019–1343 m.

References (for genus). Sars (1868), SolÍs-MarÍn (2003), Sluiter (1901a), Théel (1886a).