Eudistoma vulgare Monniot, 1988

Monniot, Françoise, 2010, Some new data on tropical western Pacific Ascidians, Zootaxa 2561 (1), pp. 1-29 : 16

Eudistoma vulgare Monniot, 1988

( Figures 16C , 17 )

Eudistoma vulgare Monniot F. 1988: 213 Fig. 7 EH. Monniot F. & Monniot C. 2001: 247.

Material. Coll. Coral Reef Research Foundation, Palau, Koror, Ulong Reef , 07°17.43’N – 134°14.46’E, 75m, 25/VII/2007, 0CDN 9571-N ( MNHN A3 EUD 349 ) . Vanuatu, Espiritu Santo, Aore Island , 15°33.24’S – 167°09.50’E, 12m, 0CDN 7766-Z ( MNHN A3 EUD 235 ); coll. S. Parker-Nance,Espiritu Santo, Malo pass 15°37.59’S – 167°10.90’E, 7m, CRCHO 452 ( MNHN A3 EUD 253 ) .

Sand particles are included into a vitreous and colourless tunic ( Fig. 16C ).The zooids have short siphons and are not grouped in systems. Numerous oral tentacles are in concentric rows. Transverse and regularly distributed muscular fibres cross longitudinal ribbons converging onto the abdomen. Numerous stigmata form the 3 rows. The abdomen is longer than the thorax and inflated by numerous testis vesicles at the stomach level. The gut loop is straight when not contracted, with a stomach rectangular in outline. The basal part of the descending limb of the intestine is dilated in a pouch ( Fig. 17 ), while the ascending limb begins in a protruding caecum. Larvae at different stages are incubated in the peribranchial cavity. The largest have a trunk 0.6mm long with 3 adhesive papillae close to each other and irregular vesicles on each side. The most discriminating characters of the species are the vitreous colourless colonies, the numerous stigmata per row and the intestinal pouch at the bottom of the gut loop. Its geographic distribution comprises Vanuatu, New Caledonia and Palau.

Figures

FIGURE 7. A: Didemnum nocturnum. B: Didemnum parau. C: Didemnum rodriguesi. D: Lissoclinum bistratum.

FIGURE 16. A: Eudistoma amplum. B: Eudistoma globosum. C: Eudistoma vulgare. D: Perophora namei.

FIGURE 17. Eudistoma vulgare: digestive loop, scale bar: 0.5mm.