(Kongsneset - Hordaland / 6 meters / 10.19.2004)

Phylum: Chordata

Subphylum: Tunicata

Class: Ascidiacea

Order: Stolidobranchia

Family: Styelidae

Scientific name: Botryllus schlosseri

 

Norwegian: kolonisekkedyr

Distribution: These beautiful formations can be seen on hard substrate or on algae, from the intertidal zone and down to 40 meters depth.

Characteristics: These sea squirts colonies form 2-4 mm thick sheets. The zooid (animal) are positioned in star shaped formation. In the center of the star they have a common cloak siphon (opening). There are usually between 6 and 12 individuals in each formation. They come in a wide range of colors.

The larval stage is pelagic. When the larva attach itself to the bottom, the rest of the colony is formed by asexual reproduction. The colony does not get older than 18 months.

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