Calcamariina O’Loughlin, 2015

O'Loughlin, P. Mark, Skarbnik-López, Jessica, Mackenzie, Melanie & VandenSpiegel, Didier, 2015, Sea cucumbers of the Kerguelen Plateau, with descriptions of new genus and species (Echinodermata: Holothuroidea), Memoirs of Museum Victoria 73, pp. 59-93 : 61-64

Calcamariina O’Loughlin gen. nov.

Zoobank LSID. http://zoobank.org:act:C8E4BCE3-5C82-421B-

A0F5-49990CC0FE8E

Diagnosis. Cucumariinid genus; body fusiform, up-turned tail; tentacles eight and two small ventral; complete calcareous body cover of imbricating thick, single-layered, knobbed, perforated plates, or thick, knobbed, rod-plates, some plates and rod-plates with spinous or knobbed part-margins; complete cover of tube feet surmounting calcareous papillae; absence of cups and tables; tentacles with thick rod-plates, rods and small perforated plates, lacking rosettes.

Type species and locality. Calcamariina hibberdi O’Loughlin & Skarbnik-López sp. nov. (south Kerguelen Plateau)

Second assigned species. Calcamariina moorea O’Loughlin & Skarbnik-López sp. nov. (south Kerguelen Plateau)

Etymology. Named Calcamariina from the Latin calx (meaning “chalk/limestone”, referring to the calcareous body wall), and mariina (from the sub-family Cucumariinae ).

Remarks. The complete body-cover of thick, calcareous single-layered perforated plates or rod-plates some with spinous or knobbed part-margins, complete cover of tube feet surmounting calcareous papillae, and absence of cups or tables, is a unique generic combination amongst the cucumariinid genera. There are no near-similar genera. We are most reluctant to establish yet another genus, but we cannot find a cucumariinid genus into which we can provisionally assign the new species.

Calcamariina hibberdi O’Loughlin & Skarbnik-López sp. nov.

Zoobank LSID. http://zoobank.org:act:548D6DA2-AAC9-4C4C-

B403-56BD914DD3CE

Tables 1–3, 5, 6; figures 1–3, 6.

Material examined. Holotype. Southern Ocean , S Kerguelen Plateau, NE Heard Island, Shell Bank, AAD Southern Champion cruise 46 haul 125, beam trawl, -51.69 76.19, 234 m, 25 Jun 2007, NMV F165750 ( UF tissue sequence code MOL AF703 ).

Paratypes. HIMI, Aurora Bank, SC 26(184), 247 m, 1 May 2003, TMAG H3542 (1) ; S Shell Bank, SC 26(253), 341 m, 8 May 2003, TMAG H3543 (1).

Description. Body fusiform with slightly up-turned oral and anal ends, anal end tapered to a tail, curved semi-U-shaped body up to 15 mm wide (U-shape width), mid-body diameter up to 6 mm (TMAG H3543); body grey/off-white, hard, calcareous, covered with low rounded calcareous papillae each with apical terminal tube foot, papillae with tube feet more numerous ventrally than dorsally. Five anal scales. Calcareous ring cucumariid-like, plates with high anterior radial and inter-radial prolongations, lacking posterior prolongations. Tentacles dendritic, 8 large, 2 ventral small. Single polian vesicle.

Ossicles of body wall and bases of papillae thick perforated plates, irregularly oval to elongate to triangular, perforations never two large perforations centrally in plates, single-layered, variably knobbed on plate surface and thickened, generally smooth at the end embedded in the body wall, many with spinous marginal projections at narrow end of plate that projects from the body wall, ossicles up to about 550 µ m long. Extended tube feet above papillae about 650 µ m long; tube feet with endplates and support plates; endplate diameters variable, up to about 200 µ m; tube foot/papilla wall supported by an open curved mesh of contiguous small perforated plates and rod-plates, elongate, curved, variable form but typically with four large central perforations and few distal small perforations, inner concave plate margin smooth, outer convex margin with blunt denticulations, plates up to about 140 µ m long. Tentacles with small concave perforated plates, marginally denticulate, about 60–100 µ m across; curved, thick, perforated plates, perforated rod-plates and rods, bluntly denticulate on the outer margin, up to 320 µ m long; lacking rosettes.

Distribution. Southern Ocean, S Kerguelen Plateau, Aurora and Shell Banks, 234– 341 m.

Etymology. Named for Ty Hibberd who followed Kirrily Moore in the curation and identification of the HIMI collections, and with appreciation of his generous collaboration on the systematics of sea cucumbers from Eastern Antarctica and HIMI.

Remarks. The holotype was donated to NMV by the AAD. Initial preservation was by freezing, with subsequent transfer to 70% ethanol. The combination of generic diagnostic characters of Calcamariina O’Loughlin gen. nov. distinguishes the two species Calcamariina hibberdi O’Loughlin & Skarbnik-López sp. nov. and Calcamariina moorea O’Loughlin & Skarbnik-López sp. nov. (below) from all other cucumariinid species. Calcamariina hibberdi is in turn distinguished from Calcamariina moorea (below) in the Remarks for that species. The paratypes above were taken by Southern Champion cruise 26 and are registered in TMAG. There are probably more specimens of this new species held but not registered and not readily accessible in the AAD in Kingston.

The superficially similar species Neopsolidium kerguelensis ( Théel, 1886) that also occurs on the Kerguelen Plateau is distinguished from the Calcamariina species by the former having narrow bare ventral inter-radii, and cups and multi-layered ossicles in the body wall (illustrated here in Figure 6 ).

Notes on determinations in Table 2:

1 Uncertain determinations; lack supporting genetic data.

2 Probable new species (very damaged specimen).

3 Phylogenetic CO1 tree in O’Loughlin et al. 2014 supports discrete species.

4 CO1 sequence clades with Psolus antarcticus specimens from Antarctica and Bouvetoya Island within a species complex.

5 Similar morphological appearance and ossicles. The always smaller, brood-protecting Psolus ephippifer may be juveniles of the sympatric and always larger, non-brood-protecting Psolus paradubiosus .

6, 7 CO1 sequences clade closely with those of Antarctic coast specimens. (See phylogenetic trees in O’Loughlin et al. 2010).

Figures

Figure 6. Microscope photos of ossicles from a specimen of Neopsolidium kerguelensis (Théel, 1886) (NMV F84997). a, multi-layered ossicle from the body wall; b, cross (bottom right) and cups from the body wall.