Scoliodota dendyi ( Mortensen, 1925 ) Yamana & Yamamoto & Ota & Kohtsuka & Omori & Iwasaki & Setiamarga, 2022

Yamana, Yusuke, Yamamoto, Masaki, Ota, Yuzo, Kohtsuka, Hisanori, Omori, Akihito, Iwasaki, Kazuma & Setiamarga, Davin H. E., 2022, Partial redescriptions of three holothurians with “ hook papillae ” (Apodida Chiridotidae): Taeniogyrus japonicus (Marenzeller, 1882), T. dendyi (Mortensen 1925), Scoliorhapis theelii (Heding, 1928), Zootaxa 5138 (4), pp. 351-387 : 371-374

Scoliodota dendyi ( Mortensen, 1925) comb. nov.

( Figs 11 , 12 )

Trochodota dendyi Mortensen, 1925: 381–383 , figs 59a, 60a, 62, 63a, Dawbin 1950: 40, Pawson 1963: 8, 1965, 248, 1968: 25, 1970: 47.

Taeniogyrus dendyi ( Mortensen, 1925) : O’Loughlin and VandenSpiegel 2010: 84, de Moura et al. 2015: 543.

Comparative material. ZMUC-HOL-57 (length 73 mm, width 2–3 mm), syntype, collected by Dr. Th. Mortensen, on Jan. 15, 1915, from Plimmerton, New Zealand. ZMUC-HOL-58 (length 133 mm, width 5–9 mm) collected by Mr. W. R. B. Oliver, on 1902, from Auckland Harbour, Waikeke, New Zealand. These were dissected by Mortensen ( Fig. 11 ). Although ZMUC-HOL- 58 specimen was labelled as “ SYNTYPES,” there can be a possibility that it was not included within the original type series [Mortensen designated the Plimmerton specimens as syntypes – there are three of these reported, so the Auckland specimens are not part of the type series (Gustav Paulay, pers. comm.)].

Description. Preserved body color white to pale orange. “Hook papillae” present in inter-radius of dorsal and ventral skin ( Fig. 11 ), along length of animal. Minute verrucae of hook papillae densely distributing anterior skin surface ( Fig. 11 A').

Ten stout tentacles, with 12 digits in smaller specimen, distal digit pair largest. Sensory cups absent. Large retractor muscles or ligaments combined calcareous ring with longitudinal muscles. Calcareous ring inclined toward ventral side, composed of five thick radial and five thick inter-radial plates ( Fig. 11C ). All plates have a posterior depression, rectangular on ventral and triangular on dorsal surface. Trapezoid anterior projection with central notch in RI, and low triangle anterior projection in IR5, no perforation present. Other eight plates have an anterior projection on near dorsal end. Other eight plates have an anterior projection on near dorsal end. Polian vesicle single, in RI. Stone canal single. Intestine has no loop. Gonadal tubules on both sides of anterior dorsal mesentery, in clusters, branched, immature in smaller specimen. One sparse row of ciliated funnels situated on right side of dorsal mesentery IR5, and another crowded band on left dorsolateral inter-radius IR3, along left ventrolateral longitudinal muscle RII. Funnels short (approximately 0.15 mm long), without stalk.

Anterior dorsal body wall with wheels and sigmoid-hooks in small specimen, but with only hooks in large specimen ( Figs 11 , 12 ). Wheels rounded-hexagonal with six spokes, 86–105 µm in diameter. Inner margin of rim parallel to outer margin. Teeth eroded, original shape and numbers indeterminable, but with no apparent discontinuities in tooth series. Spokes 16–20% as broad as diameter of wheel.

Sigmoid-hooks thick and large, arranged in circles as “hook papillae”, which are absent along center of longitudinal muscles. Sigmoid-hooks without spinelets ( Fig. 12 ) 94–109 µm and 108–134 µm long in the anterodorsal body wall of the small and large specimens, respectively ( Table 5 ).

Tentacles with, curved, mostly C-shaped, occasionally S-shaped rods with distal expansions or bifurcations ( Fig. 12 ), 46–69 µm long in large specimen ( Table 5 ).

Remarks. Our present observations agree with the morphological accounts of ossicles and external body features reported by Mortensen (1925). However, only mid-dorsal ciliated funnels were reported in that description. In this study, we confirmed the presence of another band of funnels in the left dorsolateral inter-radius. This information may be useful for the identification of this species and also useful for the revision of the genus Taeniogyrus . In the present observation, tentacles of two type materials are drawn in ( Fig. 11A, B ) and, it will be inferred that this apodid sea cucumber with retractable tentacle, as well as S. japonica .

Distribution. Sandy beach of Plimmerton, Auckland Harbour, and Stewart Island, New Zealand ( Mortensen 1925). Paterson Inlet / Whaka A Te Wera, Stewart Island, New Zealand. Kermadec Island – North Cape – Auckland – East Cape – Cook Strait – Banks Peninsula – Foveaux Strait – The Snares, New Zealand ( Pawson 1965). NW’ of Auckland Island (49°39.8'S 164°02.2'E); 69 fathoms (= 126 m), large rounded boulders with bryozoan shell sand ( Pawson 1968). Aupouri Peninsula, New Zealand ( Pawson 1970). Chatham Islands, southern part of North Island and northern part of the South Island, New Zealand ( Pawson 1970). Southern part of the South Island, Stewart Island, and the Snares Island, New Zealand ( Pawson 1970). Auckland, Campbell Island, Bounty Island and Antipodes Island, New Zealand ( Pawson 1970).

Figures

FIG. 11. Scoliodota dendyi (Mortensen) comb. nov., two syntypes of the Zoological Museum of University of Copenhagen (ZMUC), lateral views of largest specimen of the ZMUC-HOL-58 (A) and enlarged photo of it's anterior body surface (A'); smallest specimen of the ZMUC-HOL-57 (B); calcareous ring of of largest specimen of the ZMUC-HOL-58 (C), anterior left, dorsal upper. D and E, microphotograph of skin containing ossicles in anterior dorsal side of the largest specimen of the ZMUC- HOL-58 (D); and the smallest specimen of the ZMUC-HOL-57 (E). Abbreviations: ad, anterior dorsal; ca, calcareous ring; go, gonad; po, Polian vesicle; ro, retractor organ (with cutting off by Mortensen or Heding); sh, sigmoid-hook ossicle; te, tentacles; wh, wheel ossicle.

FIG. 12. Scoliodota dendyi (Mortensen) comb. nov., two syntypes deposited in the Zoological Museum of University of Copenhagen (ZMUC). A, B, ossicles from anterior dorsal body wall of the smallest specimen of the ZMUC-HOL-57 (A); and ossicles from anterior dorsal body wall and tentacle of the largest specimen of the ZMUC-HOL-58 (B). Abbreviations: ad, anterior dorsal; te, tentacle.