Didemnum guttatum Monniot F. & Monniot C., 1996

Monniot, Françoise & Monniot, Claude, 2001, Ascidians from the tropical western Pacific, Zoosystema 23 (2), pp. 201-383 : 267-268

Didemnum guttatum Monniot F. & Monniot C., 1996

Didemnum guttatum Monniot F. & Monniot C., 1996: 153 , figs 9D; 10, pl. 2E. Type locality: western Pacific.

MATERIAL EXAMINED. — Palau. Koror, Ngermutidech, 7°18.74’N, 134°31.12’E, 0.5 m, 21. VI.1993 ( MNHN Slide 1604). — Southwest Islands, Helen Reef, 2°53.03’N, 131°44.94’E, 5 m, 10.XII.1996 ( MNHN A2 DID.C 413).

Philippines. Palawan, Honda Bay, 9°52.90’N, 118°49.01’E, 18.IV.1995 ( MNHN A2 DID.C 354).

Didemnum lacertosum Monniot F., 1995 ( Fig. 120C )

Didemnum lacertosum Monniot F., 1995: 311 , fig. 7, pl. IIB. Type locality: Loyalty Islands.

MATERIAL EXAMINED. — Papua New Guinea. Milne Bay Province, Reef SE of Drawari Island, 10°18.03’S, 151°03.94’E, 16 m, 6. VI.1998 (Sample: CRRF).

DESCRIPTION

The colonies are round, no more than 1 cm in diameter, grouped in patches on corals and sponges. There are one or two common cloacal apertures, circled in white, per colony. The periphery of the colony is purple-pink ( Fig. 120C ). Spicules with numerous short rays are dense in the surface layer, sparser at the abdominal level. The zooids are very small. The oral siphon has six short, pointed lobes. The cloacal aperture is large. A bilobed languet is long in zooids near the common cloacal aperture, shorter elsewhere. The lateral thoracic organs are small, round, at the level of the third stigmata row. The retractor muscle is short, inserted high against the oesophageal peduncle. The gonads lie against the gut loop: the large testis follicle is covered by seven to eight turns of the sperm duct. The ovary contains a large protruding oocyte. The larvae are of a small size, 550 µm for the trunk. Eight to 10 pairs of ampullae encircle the three adhesive papillae. The larvae are gemmiparous.

This sample corresponds exactly to the yellow or pink species described from the Loyalty Islands. It is collected again for the first time.

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.