Studies on Japanese botryllid ascidians. V. A new species of the genus Botrylloides very similar to Botrylloides simodensis in morphology.

Botrylloides simodensis, belonging to the family Botryllidae, is a common species on the rocky shore around Shimoda. Since this species was first reported in 1981, it has been noticed that some B. simodensis colonies have distinctly different ground colors and color patterns from colonies including type specimens (holotype and all of paratypes) of B.