Botrylloides perspicuum (Herdman, 1886)
This species is a compound, colonial ascidian, with small yet elongated zooids embedded in a firm matrix or tunic. The colony grows to form thick, encrusting slabs that measure more than 4 mm in thickness. Individual zooids are organized into elongated, meandering systems, each separated by a prominent ridge. Zooids are characterized by a pharynx with approximately 18 rows of stigmata. Colonies vary greatly in color, from cream to pale yellow, pink, red, green, or bluish-purple.
In the Northeast Pacific, Botrylloides perspicuum is most similar to B. diegensis Ritter and Forsyth, 1917 and two other non-native botryllid species found in the region, B. violaceus Oka, 1927 and Botryllus schlosseri (Pallas, 1766).
Botrylloides perspicuum has been introduced to the Northeast Pacific, with confirmed records in southern California. In addition, this species has been reported from several other locations around the world, including Peru, the Caribbean, the Red Sea, Indonesia, Papua New Guinea, the Philippines, and Australia. The species is thought to be native to the Indo-West Pacific.