Rowedota, O’Loughlin & VandenSpiegel, 2010

O’Loughlin, P. Mark & VandenSpiegel, Didier, 2010, A revision of Antarctic and some Indo-Pacific apodid sea cucumbers (Echinodermata: Holothuroidea: Apodida), Memoirs of Museum Victoria 67, pp. 61-95 : 75-76

Rowedota gen. nov.

Figure 8

Diagnosis. Taeniogyrinid genus with 10 tentacles, each with 1–4 pairs of digits; chiridotid-type wheels and sigmoid hooks in body wall, rods in tentacles; wheels with teeth on inner rim in 6 discrete groups, discontinuous between spokes, not continuous series around rim; wheels scattered or aligned in the body wall, not in distinct papillae; sigmoid hooks scattered; single polian vesicle; ciliated funnels present.

Type species. Taeniogyrus allani Joshua, 1912 (see O’Loughlin and VandenSpiegel 2007).

Other species. Trochodota epiphyka O’Loughlin, 2007 (in O’Loughlin and VandenSpiegel); Trochodota shepherdi Rowe, 1976 ; Trochodota vivipara Cherbonnier, 1988 ; Trochodota mira Cherbonnier, 1988 .

Etymology. Named for Dr Frank W. E. Rowe, Senior Fellow of the Australian Museum, with appreciation of his contribution to echinoderm systematics and of his role as a valued mentor and colleague.

Remarks. Rowe (1976) based his emended diagnoses of Taeniogyrus and Trochodota on an important diagnostic character that distinguished two types of wheels amongst species of Taeniogyrinae , namely those with a continuous series and those with discontinuous grouped teeth on the inner rim. We judge that this is a significant generic character and on this diagnostic character erect the new genus. The genus has further morphological coherence with all included species having 10 tentacles, up to only 4 pairs of tentacle digits, a single polian vesicle, and the wheels never grouped into discrete papillae or bands. The new genus has geographical coherence with all included species occurring on both sides of the Indian Ocean off Australia and Madagascar.

We have included the presence of a single polian vesicle and ciliated funnels in the generic diagnosis of Rowedota gen. nov., but the presence of ciliated funnels in the Cherbonnier (1988) species and presence of a single polian vesicle in Trochodota mira have yet to be confirmed.

Frank Rowe (pers. comm.) considers the rods in the body wall illustrated by Cherbonnier (1988) for his Trochodota mira to be contaminants. Species to date referred to Trochodota , other than those referred here to the new genus Rowedota , are referred to Taeniogyrus (below). The wheels of Trochodota maculata H. L. Clark, 1921 have continuous series of teeth in the inner rim (see below). Rowe (1976) followed Clark (1921) who thought that the wheels in his new species Trochodota maculata had discontinuous series of teeth. The 1921 illustration of a wheel suggests that Clark was viewing the wheel from the side on which the continuous series is not evident as the series is partly obscured by the spokes.

No species of Rowedota gen. nov. occurs in Antarctica. The new genus is erected within this revision of genera of Taeniogyrinae .

Figures

Figure 8. a, b, SEM of wheels from body wall of Rowedota allani (Joshua, 1912) illustrating the Rowedota gen. nov. generic character of discontinuous series of teeth around the inner rim (SE Australia; from lot NMV F82715).