Trididemnum cyclops Michaelsen, 1921

Su, Shih-Wei, Hirose, Euichi, Chen, Serina Lee Siew & Mok, Michael Hin-Kiu, 2013, Photosymbiotic ascidians in Singapore: turbid waters may reduce living space, ZooKeys 305, pp. 55-65 : 57

Trididemnum cyclops Michaelsen, 1921

Trididemnum symbioticum (Peres, 1962)

Specimens examined.

ZRC-TUN-0012 (St. John’s Island, subtidal at depth 0.5 m).

Colonies are oval or irregularly shaped cushions of 2-6 mm on the long axis (Fig. 2A). Each zooid has a black dot, due to a pigment mass at the top of the endostyle (Fig. 2B). Berry-like spicules are distributed in the colonial margin and basal tunic, while they are rarely found in the surface tunic. Spicules are up to 40 mm in diameter (Fig. 2C). The biased distribution of the spicules allows the symbionts to receive sunlight for photosynthesis.