Lissoclinum timorense ( Sluiter, 1909 )

Monniot, Françoise, 2010, Some new data on tropical western Pacific Ascidians, Zootaxa 2561 (1), pp. 1-29 : 12

Lissoclinum timorense ( Sluiter, 1909)

( Figures 8D , 12B )

Didemnum timorensis Sluiter 1909: 51 .

Lissoclinum timorense: Kott 2001: 328 Fig. 148 AB, 178C–E, without synonymy; 2004: 66.

Material. Coll. N.J. Pilcher et al., Viet Nam, Con Dao Isl. , Con Son Isl., 08°41.12’N – 106°36.80’E, intertidal, 30/VII/2008 0PHG 1736-U ( MNHN A2 LIS 197 ) .

The colonies ( Fig. 12B ) are greenish crusts about 2mm thick with a round edge. The common cloacal cavity contains abundant symbiotic algae. The colony surface is raised in small warts filled with spicules. The zooids are small with the oral aperture in a slit, and a wide atrial aperture without languet. Seven stigmata are in the two first rows, 6 to 7 in the third row, and 5 in the last row per side. There is no muscular appendage. The testis is a single vesicle. The larvae are brooded in the basal layer of the colony, the trunk is 0.9mm long with 3 adhesive papillae and 8 ampullae on each side. Both the oozooid and blastozooids show 4 rows of stigmata. The spicules 45µm in diameter ( Fig. 8D ) are star-shaped with rays with a polygonal base, and made of fused rods. They have been compared to Sluiter’s specimen ( ZMA TU 1274): they well correspond in size and shape.

This species is very similar in shape, zooids and larvae to L. bistratum . It differs by the spiky colony surface and the spicules. It is distributed in the entire western Pacific.

Figures

FIGURE 8. Spicules: A: Didemnum parau. B: Didemnum rodriguesi. C: Lissoclinum roseum. D: Lissoclinum timorensis. Scale bars: 10µm.

FIGURE 12. A: Lissoclinum roseum. B: Lissoclinum timorensis.C: Diplosoma versicolor.