Select the search type
  • Site
  • Web




Ecteinacsidia diaphanis (Sluiter, 1885)

Colonial Sea Squirt

Victoria Dewar-Fowler (2013)



Fact Sheet



Physical Description


Life History & Behaviour

Reproduction and Development

Anatomy & Physiology

The Tunic


Respiratory and Circulatory Systems

Digestive System, Nutrition and Excretion

Nervous System

Evolution & Systematics

Biogeographic Distribution

Conservation & Threats

Microplastic Study

References and Links




North Beach, Heron Island. Reef crest from which E. diaphanis were collected. 
Image from SEPM STRATA Society for Sedimentary Geology©

E. diaphanis are found on the underside of rock and corals, forming cryptic communities. These communities are highly diverse and with limited space, it is assumed that E. diaphanis is competing with many other sedentary organisms for space. They increase the surface area of the rock and so provide a greater surface area for other organisms to attach. The stolons have some epiphytic growth (Gosliner et al.,1996), during my study it was noted that a small octocoral was growing on the stolon of a zooid. It is also possible that, like other ascidians, E. diaphanis forms associations with other animals.

Ascidians are ecologically important within the coral rubble communities as efficient filter-feeders. They are responsible for filtering the water, removing and storing toxins, purifying the water for other organisms. Ascidians are also prey for specialised species of molluscs, thereby contributing to the marine food web.