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Star ascidian

Star ascidian by Wembury Marine Centre

Star ascidian

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Scientific name: Botryllus schloserri
One of the most eye-catching sights on the rocky shore, this mind-boggling species resembling a collection of beautiful pressed flowers is actually a colony of individual animals!

Top facts

Category

Stats

Colonies can reach 10-20cm across

Conservation status

Common

When to see

April-October

About

This colony of sea squirts looks like a bunch of beautiful flower petals stuck next to each other to form a mosaic of stars. It takes 3-12 individuals to produce one of the star-shaped patterns. You will usually find these colonies on the underside of rocks in rockpools or sometimes on kelp fronds.

What to look for

Star ascidian have a dark, flat, gelatinous structure (tunic) with petal/star patterning covering the tunic. They often vary in colour from clear to yellow to light brown stars.

Where to find

Found all around Britain and Ireland

Did you know?

Individual star ascidians have their own intake siphon to allow nutrients and oxygen to flow into their cells, but they share an outflow opening in the centre of the star!