Corynascidia sp.

Exbodi, Françoise Monniot, 2022, Additional records of bathyal ascidians (Tunicata) from the New Caledonia region, Zootaxa 5195 (3), pp. 201-223 : 207-208

Corynascidia sp.

Figures 5–6

Station: SPANBIOS: DW 5227: 1 specimen.

The partially damaged body is circular, 18mm in diameter with a translucent cartilaginous tunic. It was attached to a piece of coral. In the body removed from the tunic ( Fig. 5A ) the apertures are almost at opposite ends of the body length. The oral siphon has six round lobes and a strong sphincter. No musculature was observed on the body wall even after staining ( Fig. 5 B,C ). The oral tentacles (about 40) are irregularly distributed in a ring, the dorsal ones larger ( Fig. 5D ). The prepharyngeal band is double. The small dorsal tubercle opens in a vertical slit. The dorsal lamina is long with triangular languets. The branchial tissue is thin and flat ( Figs 5B ; 6 ). The longitudinal vessels are complete and numerous. The stigmata do not form true spirals. In a mesh the design is irregular in one circle or half a circle with a central thickening ( Fig. 6 ) which obviously is the equivalent of a spiral stigma. The gut occupies the posterior part of the right body side in a long loop ( Fig. 5B,C ). The testis vesicles are distributed around and over the stomach and the ovary is in the gut loop. The gonoducts follow the rectum, their extremity and the anus were damaged.

Corynascidia alata Monniot C. & Monniot F., 1991 from the same geographic area has some muscles on the dorsal body side and a different branchial tissue with stigmata with several spiral turns.

Figures

FIGURE 5. Corynascidia sp.A, body removed from the tunic. B, body ventrally opened with branchial tissue. C, body ventrally opened, branchial sac removed. Scale bars = 1cm. D, neural area.

FIGURE 6. Corynascidia sp. Two different parts of the branchial tissue stained with hemalum. Scale bar = 1mm.