A sourced illustration has not yet been added. This gap is included in the coverage record.

Overview

Colonies form flat or fleshy sheets. Small zooids are arranged in conspicuous stars around shared central cloacal openings. Colony colour varies greatly.

It grows on stable surfaces, including algae and artificial structures, especially in sheltered sites and docks. Colonies can cover the living substratum they grow on.

Budding and vascular regeneration renew colonies. Recognition between colonies regulates fusion, which can produce genetic chimeras and competition among cell lineages. These processes support research on regeneration and allorecognition. A 2025 GigaScience assembly specifically represents subclade A1.

Colonial sheets with star-arranged zooidsShared central cloacal openingsHighly variable colony colourBudding and vascular regenerationGenetically controlled allorecognitionChimera formation after fusion
01

Origins & earliest records

The selected sources do not establish an evolutionary origin. The authority Pallas, 1766 records naming, and genome assembly dates record sequencing work; neither marks the species' origin. The original type material has not been examined.

02

Evidence & interpretation

MarLIN species account (description, habitat, distribution, taxonomy); GigaScience genome paper, DOI 10.1093/gigascience/giaf097 (Introduction).

Selected bibliography

Documented works and useful reading. This is not a list of every appearance.

  1. 01

    First chromosome-level genome assembly of the colonial chordate model Botryllus schlosseri (Tunicata)

    · 2025

    Selected bibliography; De Thier et al., GigaScience 14, giaf097 (2025), DOI 10.1093/gigascience/giaf097.

  2. 02

    Star ascidian (Botryllus schlosseri)

    · 2008

    Selected bibliography; MarLIN institutional species account.

Family, evolution & connections

Taxonomic classification

A hierarchy of classified groups, not a chain of direct ancestors.

Source note: The placement and the authority Pallas, 1766 come from MarLIN's taxonomy section. The genome paper refers to the group as Tunicata.

  1. phylumChordata
  2. classAscidiacea
  3. orderStolidobranchia
  4. familyStyelidae

References

Sources supporting this profile. Linked pages have their own scope and editorial standards.

  1. Institutional species accountStar ascidian (Botryllus schlosseri)Research access: 2026-10-07
  2. Peer-reviewed articleFirst chromosome-level genome assembly of the colonial chordate model Botryllus schlosseri (Tunicata)Research access: 2026-10-07
  3. Primary scientific publicationA chromosome-level genome assembly of Botryllus schlosseriResearch access: 2026-10-07

Image credits

A sourced illustration has not yet been added. This gap is included in the coverage record.

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