Perophora japonica Oka, 1927
This species is a social ascidian, with individual zooids connected basally by stolons. Together, zooids and stolons often form a dense mass similar to a tiny bunch of grapes. Individual zooids are globular in shape, measure 2-4 mm in diameter, and covered by a pale green tunic. Stolons are characterized by distinct, star-shaped flattened terminal buds, yellow in color.
In the Northeast Pacific, Perophora japonica is most similar to P. annectens Ritter, 1893.
Perophora japonica has been introduced to the Northeast Pacific, and was discovered initially in northern California. This species also has been collected from other locations around the world, including Great Britain, northern Europe, and eastern Russia (Lambert 2005). Its native geographical distribution includes Japan and Korea.