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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




Ascidians, commonly known as sea squirts, are the largest and most diverse class of animals found within the sub-phylum of tunicates, with approximately 3000 described species (Shenkar et al., 2012). They are highly derived invertebrates with larval stages possessing notochords, firmly placing them in the chordates, a sister group to the vertebrates (Delsuc et al., 2006)

Ecteinascidians are small group of sedentary colonial ascidians found throughout the world’s oceans. Ecteinascidia diaphanis is a small cryptic animal found on the underside of rocks and ledges within shallow waters in the Western Pacific. This elegant animal is often over looked and due to its small range very little information regarding this species is available.

Ecteinascidia diaphanis colony collected from North Beach, Heron Island, September 2013.

As with all marine organisms, ascidians come under stress from changing conditions, these may be daily changes or more long term changes related to anthropogenic sources. As part of this project, I carried out a study looking into the response of E. diaphanis when subjected to microplastics. The interesting findings of this study can be found under Conservation and Threats: Microplastic Study.