Eudistoma carolinense Van Name, 1945

Monniot, Françoise, 2016, Ascidians (Tunicata) of the French Guiana Expedition, Zootaxa 4114 (3), pp. 201-245 : 209-210

Eudistoma carolinense Van Name, 1945

Figure 7 .

Stations. SS1; SC12; SS10; SS12; CP4408.

The long thin lobes of the colonies, deeply incrusted with sand, arise from a narrow common base ( Fig. 7 A). The top of the lobes are slightly enlarged and contain 6 to 8 thoraces. The zooids are only 3mm in length and present inside the upper part of the colony lobes. The body wall is thin with a weak musculature. Both siphons have 6 lobes. The thorax has a square shape ( Fig. 7 C) with 16 stigmata per half row in each of the two first rows. The oesophagus is long compared to the thorax. The short stomach ( Fig. 7 D) is followed by an enlarged mid-intestine. The rectum begins in a circular caecum. No pyloric gland could be seen. The gonads inside the gut loop have 6 to 8 testis vesicles and a central ovary. A single tadpole is incubated in the atrial cavity. The larvae trunk is approximately 0.4mm in length ( Fig. 7 B). The 3 adhesive papillae with short peduncles are lined by 8 to 9 rounded ampullae on each side. These observations exactly correspond to Van Name’s (1945) description and to Caribbean material ( Monniot F. 1983 and fig.). It is likely that E. carolinense in Millar (1977) refers to 2 different species as he suggested, only his figure 6 representing E. carolinense .

This species has a wide distribution from Florida to Brazil but is limited to the western Atlantic Ocean.

Figures

FIGURE 7. Eudistoma carolinense. A, colony; B, two larvae, scale 0.2 mm, C, thorax, D, gut loop. B to D stained with hemalum.