Fusibility of Colonies in Natural Populations of the Compound Ascidian, Botrylloides violaceus

Abstract

1. Twenty colonies of Botrylloides violaceus were collected from two stations and fusion experiments were carried out in every combination of colonies. 2. Fusible combinations among colonies in one station gave a percentage of 8.9; those among colonies in the other station showed a high percentage of 28.9. 3. It is suggested that the fusion incompatibility in Botrylloides violaceus is also controlled by a mechanism similar or related to that found in Botryllus primigenus, i.e., by a series of multiple alleles at a single locus.