Psolicrux iuvenilesi O’Loughin & Manjón-Cabeza

O’Loughlin, Mark, Manjón-Cabeza, Eugenia & Ruiz, Francina Moya, 2009, Antarctic holothuroids from the Bellingshausen Sea, with descriptions of new species (Echinodermata: Holothuroidea), Zootaxa 2016, pp. 1-16: 6-8

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Psolicrux iuvenilesi O’Loughin & Manjón-Cabeza

sp. nov.

Psolicrux iuvenilesi O’Loughin & Manjón-Cabeza  sp. nov.

Figure 2 a–cView FIGURE 2. a – c; table 1.

Material examined. Holotype. Antarctic Peninsula, Gerlache Strait, BENTART– 2003, R/V Hesperides  , stn PA 23, 64.9255ºS, 63.6068ºW, 656 m, 25 Feb 2003, MNCNAbout MNCN 29.04/ 128; dorsal body ossicles slide NMVAbout NMV F 161522; ventral body ossicles slide F 161523; tentacle ossicles slide F 161524.

Paratypes. Type locality and date, MNCNAbout MNCN 29.04/ 129 (4).

Other material. Paraiso Bay, R/V Hesperides  , stn BP 21, 64.90ºS, 63.01ºW, 101 m, 23 Feb 2003. Eastern Antarctica  , Prydz Bay, Fram Bank, 444–453 m, 26 Feb 1991, F 68053View Materials (1); Enderby Land, 386–400, 15 Nov 1985, F 84985View Materials (1).

Diagnosis. Specimens up to 29 mm long (tentacles withdrawn), widest diameter 11 mm; thin, flexible, calcareous, body wall with minute projecting spines; distinct sole and “belly” ventrally; oral cone, tapered anal cone forming distinct “tail”, both oral and anal cones frequently upturned; 10 subequal dendritic tentacles; large tube feet in mid-ventral and latero-ventral paired radial series defining a distinct sole with broad bare interradii; single latero-ventral row (of the paired series) bordering the bare interradii typically close, outer row of paired series more spaced; smaller tube feet scattered dorsally and laterally and on oral and anal cones; tube feet do not cross introvert; radial plates of calcareous ring elongate, sub-rectangular, with deep posterior notch; interradial plates elongate, tapered and rounded anteriorly, with shallow rounded indentation posteriorly.

Ossicles in body wall numerous, imbricate, large, thick, single-layered, perforated, smooth plates with angled narrow distally spinous spire, plate and spire up to 480 µ m long, spires typically 160 µ m long; plates irregular in size and form; spired plates similar dorsally and ventrally; lacking small branched bluntly spinous rods and crosses. Largest tentacle ossicles irregularly oval to elongate, thick, knobbed, curved, perforated plates, up to 640 µ m long; smallest plates thin, smooth, marginally bluntly denticulate.

Colour (preserved). Pale grey-brown.

Distribution. Western Antarctica  (Gerlache Strait), Eastern Antarctica  (Fram Bank); 101- 656 m.

Etymology. From the Latin iuveniles (young people) in recognition of the skilled assistance provided by the young University of Málaga students Blanca Gallego Tevar, Carolina Yuste Florido and Juan Miguel Pérez Ramos. 

Remarks. O’Loughlin (2002) reviewed Psolidium (Cucumaria) coatsi Vaney, 1908  , erected the new genus Psolicrux  for the species, and judged that Cucumaria conspicua Vaney, 1908  , Psolidium navicula Ekman, 1927  and Psolidium bistriatum Ludwig & Heding, 1935  were junior synonyms. Cucumaria conspicua Vaney, 1908  is removed above from the synonymy by O’Loughlin (2002), and referred to Cucamba psolidiformis ( Vaney, 1908)  .

Body form, knobbed cross ossicles and spired plate ossicles of Psolicrux coatsi ( Vaney, 1908)  were illustrated by O’Loughlin (2002, figs 3 c–f). In examining the material for that work it was noted that knobbed crosses were sometimes not found, and this was judged to be a sampling artefact (O’Loughlin, pers. obs.). In this work there has been a consistent absence of knobbed crosses in some specimens. The specimens lacking knobbed crosses are referred to the new species Psolicrux iuvenilesi O’Loughin & Manjón-Cabeza  sp. nov. In addition to the absence of knobbed crosses, the specimens are smaller, and the largest tentacle ossicles are thick knobbed oval to elongate plates while in Psolicrux coatsi (Vaney)  the largest tentacle ossicles are thick, narrow, bluntly spinous, perforated rods, up to 536 µ m long ( Figure 2View FIGURE 2. a – c d).


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