Tunicate (IMAGE) PLOS Caption Recognized as one of the closest relatives to vertebrates, the colonial urochordate Botrylloides leachi possesses unique modes for propagating and regenerating that make this species a robust model organism for studying diverse biological issues related to development, immunology, stem cells and regeneration. Credit Reshef et al. Usage Restrictions Please cite the authors and PLoS Biology as the source. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.