Culeolus elegans 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 : 461

Culeolus elegans Monniot C. & Monniot F., 1991

Figure 18

Stations: Kanadeep CP 5062; 5087; 5092; 5109. Seven specimens.

The seven specimens collected all have the same shape with a triangular body attached to a long thin and stiff peduncle sometimes reaching 25cm in length ( Fig. 18A, B ). The outer tunic on the body is soft and covered with minute papillae and sediment over a thicker fibrous inner envelope. A half arc of larger papillae encircles the dorsal body side at some distance from the atrial aperture. The horny peduncle begins near the oral siphon. The body wall is thin with circular muscles at the base of the siphons and well spaced muscular bundles on the body. The oral tentacles with few ramifications are inserted at the base of a velum. The dorsal tubercle opens in a vertical slit. The dorsal lamina has large flat triangular languets. The branchial tissue is damaged in all specimens, with a large part ejected through the atrial aperture. Near the prepharyngeal band longitudinal sinuses can be seen grouped in 6 low folds but their exact number cannot be determined. The gut is isodiametric in a long open loop ( Fig. 18C ). A series of hepatic lobes lie along the oesophagus and stomach which are not delimited from the intestine. The anus is fringed with numerous lobes. The gonad number varies ( Fig.18C, D ) and does not depend on the specimen size. The largest specimen (2.2 cm in diameter) has five gonads of different length on the right body side and two gonads inside the gut loop, there are no gonads outside of the gut. Each gonad comprises a succession of hermaphrodite lobes covered by an endocarp and linked by the oviduct. Both genital papillae are short and close together. No endocarp were found on the body wall. Rare spicules can be found in the body wall and gonads.

Culeolus elegans is known only from the New Caledonian area where it seems to be common. It differs from Culeolus herdmanni Sluiter, 1904 , (also present in New Caledonia: Monniot C. & F. 1991) which has six branchial folds per side but large endocarps on the body wall.

Figures

FIGURE 18. Culeolus elegans. A, one specimen; B, another specimen; C, body ventrally opened; D, gonad. Scale bars = 1cm.