Didemnum biglutinum Monniot F., 1995

Monniot, Françoise & Monniot, Claude, 2001, Ascidians from the tropical western Pacific, Zoosystema 23 (2), pp. 201-383 : 266-267

Didemnum biglutinum Monniot F., 1995

Didemnum biglutinum Monniot F., 1995: 300 . Type locality: New Caledonia. — Monniot F. & Monniot C. 1996: 152, fig. 9C, pl. 2D, Palau.

MATERIAL EXAMINED. — Palau. E Ngeruktabel, Topkukau, marine cove, 7°15.94’N, 134°27.01’E, 1 m, 9.III.1994 ( MNHN A2 DID.C 418).

Federated States of Micronesia. Pohnpei, NE lagoon, Tehpehk Island, bath sponge farm growing on nylon line, 6°57.68’N, 158°17.85’E, 8 m, 15.X.1996 ( MNHN A2 DID.C 416).

Didemnum cuculliferum ( Sluiter, 1909) ( Fig. 120B )

Diplosomoides cuculliferum Sluiter, 1909: 90 . Type locality: Indonesia.

Didemnum cuculliferum – Kott 1981: 164, figs 16; 22a, b, Fiji. — Monniot C. & Monniot F. 1987: 28, fig. 7D, E, pl. VB, Polynesia. — Monniot F. 1995: 305, pl. 1D, 4A, New Caledonia.

MATERIAL EXAMINED. — Palau. Ngermutidech, 7°18.74’N, 134°31.12’E, 0.5 m, 14. VI.1996 ( MNHN A2 DID.C 425).

Fiji. Coll. Ireland ( MNHN A2 DID.C 72).

DESCRIPTION

In life the colonies have the colour of red currant ( Fig. 120B ). They are 1-2 cm in diameter, thin and soft, growing on sea grass. The upper surface is marked by many long irregular papillae. The spicules are dense throughout the colony. The oral siphon has six very short lobes. The cloacal aperture is not very wide, and there is no cloacal languet. The lateral thoracic organs lie on the middle of each side above the third or fourth stigmata row. The thorax has a rectangular shape. The retractor muscle is about as long as the thorax. The waist is short. The abdomen folds under the thorax and contains a twisted gut loop. The one large testis follicle is covered by six coils of the sperm duct. A brown crescent-like gland lies against the intestinal loop.

There are no larvae in these colonies.

The spicules correspond exactly to those observed in collections from New Caledonia, Fiji, and Polynesia.

REMARKS

Even without larvae this species is identifiable by its colour in life and by the papillated surface of the small colonies. Its distribution is wide in the western Pacific Ocean: Indonesia, Palau, New Caledonia, Fiji and the islands of Polynesia.

Figures

FIG. 120. — A, Didemnum algasedens n. sp.; B, Didemnum cuculliferum (Sluiter, 1909); C, Didemnum lacertosum Monniot F., 1995; D, Didemnum madeleinae n. sp.; E, Didemnum obscurum Monniot F., 1969; F, Didemnum rodriguesi Rocha & Monniot F., 1993.