Lissoclinum bistratum

Lissoclinum bistratum (Sluiter, 1905)

Didemnum bistratum Sluiter, 1905

Didemnum gottschaldti Tokioka, 1950

Didemnum pulvinum Tokioka, 1954

Leptoclinum bistratum (Sluiter, 1905)

Lissoclinum pulvinum (Tokioka, 1954)

Specimens examined.

NMNS-7027-003, NMNS-7027-004, ZRC-TUN-0002, ZRC.TUN.0004, ZRC-TUN-0007, ZRC-TUN-0008 and ZRC-TUN-0014 (Pulau Semakau, subtidal at depth 0.5 m), ZRC-TUN-0010 (Sentosa, subtidal at depth 0.5 m).

Colonies are oval cushions of 4 mm on the long axis (Fig. 2F). The photosymbiont Prochloron gives the colonies a green color, while the colonial margin and bottom are white due to dense aggregations of globular spicules in the tunic (Fig. 2G). The thorax has four stigmatal rows. It is difficult to count accurately the number of stigmata owing to the distortion of thoraxes caused by the shrinkage of zooids upon fixation. There are about seven stigmata in each row. Some zooids have a testis with an uncoiled vas deferens (Fig. 2H). Kott (1982) reported this species from Singapore.