Diplosoma listerianum (Milne-Edwards, 1841)
Grey encrusting compound tunicate
This species is a compound, colonial ascidian, with small, individual zooids embedded in a common matrix or tunic. The colony can grow extensively, forming soft, gelatinous sheets that measure 1-3 mm in thickness and up to several centimeters across. Individual zooids are very small, approximately 1-2 mm. The tunic lacks calcareous spicules, but often possesses white pigment flecks. Often translucent and either colorless or with a gray, light green, or tan hue.
In the Northeast Pacific, Diplosoma listerianum is most similar to other soft or gelatinous, encrusting colonial tunicates, including species of Didemnum and Eudistoma.
Ecology and Distribution
Diplosoma listerianum has been recorded in the Northeast Pacific from British Columbia to California. This species also has been collected from numerous locations around the world, including the east coasts of North and South America, northern Europe and Great Britain, South Africa, Japan, New Zealand, and Hawaii. Its native geographical range remains unknown, and is considered cryptogenic.
- Diplosoma macdonaldi Herdman, 1886 (synonym)