Eudistoma globosum Kott, 1957

Monniot, Françoise, 2010, Some new data on tropical western Pacific Ascidians, Zootaxa 2561 (1), pp. 1-29 : 15-16

Eudistoma globosum Kott, 1957

( Figure 16B )

Eudistoma globosum Kott, 1957: 72 Figs 1–2; 1990a: 210 Fig. 79a–d. Monniot F. & Monniot C. 2008: 84 Fig. 53.

Material. Coll. Coral reef Research Foundation, Palau, Northern Reefs , Ngerael Reef, 02°52.24’N – 131°44.55’E, 15m, 29/ VI /2008, 0CDN 9615-L (A3 EUD 348 ) ;

The colonies ( Fig.16B ) are round or club-shaped with a peculiar arrangement of sedimentary particles in the tunic. The basal part of the tunic is densely impregnated with sand, which extends internally in a central sandy core. Over it, the tunic forms a cap with progressively less sand towards the colony surface which is dark-green. The dark pigment cells are round and remain black in formalin. Some rust-coloured cells are found in the layer of tunic enclosing the zooids. The zooids 10–12mm long have a posterior vascular appendage. They are arranged in circular systems. The branchial sac counts 42, 32 and 31 stigmata in the successive rows per side.

Specimens from Queensland identified by Kott (1990 a: QM GH4579) have been examined, one of them with a larva the same as those of this collection. The larvae are 1mm long with 3 short-stemmed adhesive papillae separated by 4 thick vesicles, the 2 central ones protruding on each lateral side of the larva giving the aspect of 2 pairs.

The newly collected specimens confirm our previous identification ( Monniot & Monniot 2008). Recorded from west and east Australia and Palau, its presence in Tasmania ( Kott 2006) seems questionable.

Figures

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