Trididemnum cyclops Michaelsen, 1921

Monniot, Françoise, 2010, Some new data on tropical western Pacific Ascidians, Zootaxa 2561 (1), pp. 1-29 : 3-4

Trididemnum cyclops Michaelsen, 1921

( Figure 2A )

Trididemnum cyclops Michaelsen, 1921: 19 ; Kott: 2001:264 and synonymy; Monniot F. & Monniot C.:2001: 262

Material. Palau, coll. Coral Reef Research Foundation, SW islands, Helen Reef (Hotsarihi), 02°55.78’N – 131°46.42’E, 1m, 25/VIII/2008, 0CDN 9897- R ( MNHN A2 TRI 187 ) . Zanzibar, coll. Richmond ( MNHN A2 TRI 121 ) . Seychelles, coll. Lewin ( MNHN A2 TRI 61 ) . Madagascar, coll. Vasseur, Tulear, ( MNHN A2 TRI 179 ) .

Light green or pink all colonies have the same cushion shape 1 to 1.5 cm in length and 3 mm in thickness when fixed ( Fig. 2A ). One or two apertures are at the top of each colony. The surface layer is aspicular. The common cloacal cavity is filled with symbiotic algae. Rare dark pigment cells are scattered among the spicules in the tunic. The zooids have a dark pigment spot at the top of the endostyle and some pigment cells above the stomach. The dorsal lobe of the oral siphon is shorter than the 5 others. The cloacal aperture is transverse. As in all localities where they have been observed there are 8 oval stigmata per side in the first branchial row. The waist is long with a long muscular appendage. Six to seven turns of the sperm duct enclose the single testis vesicle. Larvae were not found in these colonies. The spicules have numerous rays as figured in Kott (2001 Fig.174D).

T. cyclops is a common shallow water species widely distributed in the Pacific and Indian Oceans.

Figures

FIGURE 2. A:Trididemnum cyclops. B: Trididemnum lanugineum n. sp. C: Trididemnum biglutinum from New Guinea. D: Trididemnum biglutinum from Palau.