Clarkiella deichmannae, O’Loughlin, Mark, 2009

O’Loughlin, Mark, 2009, BANZARE holothuroids (Echinodermata: Holothuroidea), Zootaxa 2196, pp. 1-18 : 4-6

Clarkiella deichmannae sp. nov.

Figure 2a–c ; table 1.

Material examined. Holotype. Kerguelen Is,? 278–329 m, BANZARE, 26 Feb 1930, SAM K2474. Paratypes. Type series, SAM K2375 (6). Other material. Off NE Tasmania, 41°03'S 148°42'E, 128–676 m, BANZARE stn 115, 24 Mar 1931, SAM K2367 (1).

Diagnosis. Up to 22 mm long (strongly contracted; excluding tentacles); body fusiform, lacking tail; mouth anterior, anus posterior; typically 15 dendritic tentacles, 5 pairs of large, 5 small between pairs (1 pair of small and total of 6 small in holotype); tube feet in 5 radial series, up to 4 wide, each series comprising 2 zig-zag rows (strong contraction of body creates superficial appearance of complete cover of tube feet); tube feet series cross introvert; calcareous ring lacks posterior prolongations, 5 long radial plates sub-rectangular with deep posterior “forked” notch, 5 long wide interradial plates with anterior taper and shallow posterior notch with upturned tapered outer ends.

Body wall ossicles abundant tables; discs irregularly round to slightly oval, typically 104 µ m long (up to 112 µ m), typically 16 perforations (8 central, 8 marginal), variably few or more; spires with 2 pillars, each comprising 2 fused pillars, 8–12 apical short stout spines, spires 48 µ m high; tube foot endplate diameters 208 µ m. Tentacle ossicles rod-derived perforated plates, variably elongate, branched, curved, up to 264 µ m long.

Distribution. Kerguelen Is, NE Tasmania, 128–676 m (see Remarks).

Etymology. Named for Elizabeth Deichmann, formerly of Harvard University, with appreciative remembrance of her significant contribution to holothuroid systematics and in particular for her systematic work on some BANZARE specimens.

Remarks. In Heding & Panning (1954) Panning recorded that Svend Heding died before their manuscript was completed, and before Svend was able to complete a Discovery Report. Panning noted that descriptions of the new genus Clarkiella Heding, 1954 and new species Clarkiella discoveryi Heding, 1954 were from the notes of Heding, and were included in Heding & Panning (1954) in collaboration with Dr. E. Deichmann (Harvard University). Clarkiella was assigned to the new sub-family Cladolabinae Heding & Panning, 1954. The description of Clarkiella discoveryi refers to the largest specimen of the species as the 60 mm long “ type ”, with 16 tentacles not the normal 15. The body was evenly covered with tube feet. No Discovery station data were referred to, or any specimen registration recorded. Panning (Heding & Panning 1954) recorded that the work on the Discovery material was taken over by Dr. Deichmann. This was not completed, and no Discovery Report has been published. All of the Discovery holothuroids that remained on loan to the Smithsonian US National Museum of Natural History are currently (July 2009) in Museum Victoria for determination, on their way to the British Museum of Natural History. Type material for Clarkiella discoveryi Heding, 1954 is not with the Discovery collection. The holotype is listed with the University of Copenhagen Zoology Museum holothuroid types (reg. no. ZMUC 64).

The diagnostic characters of the new species are similar to Clarkiella discoveryi Heding, 1954 from the South Atlantic, and the new species is assigned to Clarkiella Heding, 1954 . There are insufficient data in the original description of C. discoveryi to conclude that it is conspecific with the Kerguelen material. No type locality or ossicle measurements were published. The type for C. discoveryi was significantly larger, and was covered evenly with tube feet. The specimens of C. dichmannae are strongly contracted, and initially it was thought that tube feet covered the body. It was subsequently recognized that they are in wide radial bands. The distinctive diagnostic characters of Clarkiella deichmannae sp. nov. are: fusiform body; 15 tentacles; ring lacking posterior prolongations; multiple rows radial series of tube feet; two–pillared spires on the tables, table discs slightly irregular with typically 8 central and 8 outer perforations and width 104 µ m, spires typically 48 µ m long.

Locality data are uncertain. No station number is recorded with the type material that was found with the BANZARE collection, but the date of collection is recorded as 26.2.1930. Johnston (1937) records station 60 and three shore collections on Royal Sound, Kerguelen I., on 25 February 1930, and station 61 and a shore collection on 27 February. The numbers 329–278 are recorded on the label and appear to indicate depth, presumably meters like other BANZARE depths. There is no uncertainty about station 115 (off Tasmania) for a single specimen that is judged here to be conspecific with the Kerguelen specimens. No other shallow holothuroid species has a common distribution of Kerguelen and Tasmania.

Figures

FIGURE 2. a – c, Clarkiella deichmannae sp. nov.: a, holotype (SAM K 2474, 22 mm long), (insert) radial (left) and interradial plates of calcareous ring; b, large tentacle ossicle (264 µ m long, paratype, SAM K 2375); c, tables from middorsal body wall (photos above, drawings below), discs (112 µ m long) with spires (paratype, SAM K 2375); d, Pseudocnus intermedia (Théel, 1886): thin elongate body (SAM K 2384, 65 mm long), (left insert, NMV F 84984) middorsal body wall knobbed buttons (128 µ m long) and terminally spinous plates (176 µ m long). d (right insert): Pseudocnus laevigatus (Verrill, 1876): distally spinous plate from mid-dorsal body wall (220 µ m long, SAM K 2387). e, Trachythyone cynthiae sp. nov.: holotype (NMV F 165718, 50 mm long), (insert) radial (left) and interradial plates of calcareous ring. f, Trachythyone mackenzieae sp. nov.: holotype (NMV F 68073, 37 mm long), (insert) radial (left) and interradial plates of calcareous ring.