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Botryllus tuberatus (Ritter & Forsyth, 1917)

Pacific Star Tunicate

Adeline Ang (2014)



Fact Sheet

Brief Summary

Physical Description

External Features

Internal Features

Slides Preparation


Life History & Behaviour

Feeding Mechanisms


Internal Transport & Movement

Asexual Reproduction

Sexual Reproduction

Anatomy & Physiology

Evolution & Systematics

Biogeographic Distribution

Biofouling Threats

References & Links


B. tuberatus are sessile suspension feeders that filter particles from the water column (Lesser et al. 1992).  As this species is not often recorded, it is generally difficult to describe specifically where it could be found.  Records have shown that B. tuberatus grows in water depths of 1-45m (EOL 2014).  All species of ascidians do require substrates to grow on, including B. tuberatus.
Past Australian records have shown that it could be found from intertidal areas, reef-flat habitats and on the underside of rubble (Kott 1985).  Many of these areas gradually shifts from one to another, which also makes it hard to pinpoint specific habitats.  Past records have also shown that B. tuberatus could be found on man-made structures, such as boat hulls and jetty pilings (Boyle, Janiak & Craig 2004).  They were often one of the first few organisms to grow on such areas, followed by succession by other organisms from the same or different phyla (Boyle, Janiak & Craig 2004).  This meant that they could also be categorised under biofouling organisms.