Ascidia archaia Sluiter, 1890

Monniot, Françoise, 2018, Ascidians collected during the Madibenthos expedition in Martinique: 1 - Phlebobranchia, Zootaxa 4387 (3), pp. 451-472 : 451-452

Ascidia archaia Sluiter, 1890

Figs 1–2

Stations. AM 0 6, 14°30,4N–61°05,3W, 1m; AR 121, 14°26,4N–60°49,5W, 2m.

(MNHN P5 ASC.A 430).

Ascidia archaia Sluiter, 1890

Ascidia corelloides: Monniot C. 1983 .

The anatomical characters described for this species are the same in all specimens collected from various geographic areas. The tunic is vitreous with the body and gut visible ( Fig.1B ). The oral siphon has 8 lobes with ocelli. The oral tentacles vary in number 14–18 and smaller ones between them; the dorsal tubercle is small and urn-shaped. The prepharyngeal groove is not indented dorsally ( Fig. 1A ). The dorsal lamina is double anteriorly to become a single blade with small teeth at the edge. The branchial meshes have 4–5 stigmata and no parastigmatic vessels but there are intermediate papillae on the longitudinal vessels ( Fig.2 ). Thirty four longitudinal vessels were counted on the right side in one animal. The muscles are particularly weak on the siphons and the body wall ( Fig.1A ). The gut forms a long intestinal loop enclosing an ovary in two parts ( Fig.1A ): the proximal end of the ovary with oocytes occupies the top of the primary gut loop and is followed by a characteristic wide oviduct parallel to the rectum containing eggs and immature larvae ( Fig.1A ). Few larvae were in the atrial cavity of one specimen.

Ascidia archaia Sluiter, 1890 recorded for the first time in Indonesia was found again under several names in all tropical oceans. In the Caribbean area this species was described as Ascidia corelloides by Van Name, 1924, and this name was also used by Monniot C. (1983) for specimens collected in Guadeloupe. Kott (1985) synonymised Ascidia rhabdophora Sluiter, 1904 and A. corelloides with A. archaia , an opinion shared by Monniot C. & F. (1987) who described ascidians from Polynesia. A. archaia is the species name also used by Bonnet & Rocha (2011) for a specimen from Panama.

Figures

FIGURE 1. Ascidia archaia. A, body ventrally opened and stained; B, three undissected specimens in formalin (scale bar = 1cm).

FIGURE 2. Ascidia archaia.part of the branchial tissue.