Ecteinascidia minuta, Traustedt, 1882

Monniot, Françoise, 2018, Ascidians collected during the Madibenthos expedition in Martinique: 1 - Phlebobranchia, Zootaxa 4387 (3), pp. 451-472 : 466-468

Corella minuta Traustedt, 1882

Fig. 16

Stations : AS 66; AR 132; AR 309. ( MNHN P4 COR.A 72) Monniot F. 2016: and synonymy

Attached by the right body side to algae or to corals this ascidian has a transparent cartilaginous tunic ( Fig.16B ) with siphons opening at 90° to each other. Some brown pigment remained in a specimen fixed with formalin on the siphons and the branchial sac. There are 8 oral lobes with ocelli. Twenty-eight tentacles of two orders of size are separated by small buttons. The prepharyngeal groove is not dorsally indented. The dorsal tubercle opens in a slit. The dorsal lamina has triangular languets of increasing length posteriorly. The branchial tissue ( Fig. 16A ) contains 35 longitudinal vessels on the right side of the largest specimen of 12mm. The spiral stigmata are very regular. The gut forms a wide loop on half of the right body side ( Fig.16 A ).The stomach shows 5 folds seen by the internal side and has a caecum. The anus his smooth with 2 lips. The ovary consists of several lobes, some of them around the gut ( Fig.16A ) and others lie on the intestinal loop mixed with testis vesicles.

The musculature is weak on the siphons; on the body it is reduced to a few longitudinal short fibres beginning at the prepharyngeal level and do not extend on the body sides. A few short muscles are on the sides of the atrial opening.

All descriptive elements are the same for specimens recorded in the tropical Atlantic, Indian or Pacific Oceans ( Monniot F. 2016) but the origin of this species is unknown.

Figures

FIGURE 16. Corella minuta. A, dissection stained with hemalum; B, Body in formalin (scale bar = 5mm)