Culeolus caudatus Monniot C. & Monniot F., 1991

Monniot, Francoise, 2021, New records of deep-sea ascidians (Tunicata, Ascidiacea) from the New Caledonia region, Zootaxa 4996 (3), pp. 443-468 : 460-461

Culeolus caudatus Monniot C. & Monniot F., 1991

Figure 17

Station: Kanadeep CP 5072. One specimen. The body is 5.5 cm long on a stiff peduncle of 15 cm incrusted with sand ( Fig. 17A ). The peduncle is not sclerified it presents a longitudinal groove. A crest of tunic forms a circle at some distance from the atrial aperture. The body wall is thin with spaced muscular ribbons on each side ( Fig.17B,C ). It is prolonged by a triangular mass of spongy tissue without muscles close to the origin of the peduncle ( Fig. 17C ). Spicules are present in all tissues. The oral tentacles have 3 orders of ramifications. The dorsal tubercle opens in a flat S above the dorsal ganglion. The branchial tissue was partly ejected from the body though it was possible to see most details. The dorsal lamina is composed of numerous papillae. There are 6 branchial folds per side, not well delimited from each other, a tentative formula on the right side is:

E – 6 (6) (4) 4 (7) 7 (8) 4 (8) 6 (7) 2 – DL

The digestive loop comprises a long stomach and the ascending intestine situated close to the endostyle followed by a curve and a shorter rectum ( Fig. 17D ). The anus is lobed. The hepatic gland is voluminous with two large papillate masses and two or three smaller glands on the intestine Fig. 17 D ). There is one long gonad on each side ( Fig. 17B ). The left gonad with seven lobes is located inside the gut loop ( Fig. 16D ). The right gonad has also seven lobes and is parallel and close to the endostyle. The sperm duct and oviduct are long and open together in joined papillae near the atrial aperture ( Fig. 17B ). No endocarps were found on the body wall. An ampulla of the internal layer of the body wall is present anterior to the right gonad but does not look as an endocarp but more as an inflated body wall trabecula.

Though partially damaged, the Kanadeep specimen well corresponds to C. caudatus described from the same region.

Figures

FIGURE 16. Herdmania columna. A, branchial sac; B, body; C, gut and gonads. Scale bars = 1cm.

FIGURE 17. Culeolus caudatus. A, one specimen; B, body ventrally opened; C, body without tunic; D, gut and left gonad. Scale bars = 1cm.