Responses of Bugula neritina, an arborescent bryozoan to the effects of real and imitation predation events by the nudibranch Polycera hedgpethi

For colonial organisms physical damage or predation can result in the loss of part of the colony. Although the colony may survive, loss of part of the colony may alter patterns of growth and reproduction. In this study the response of Bugula neritina, an arborescent bryozoan, to physical damage was tested in three experiments: 1) short term regenerative responses to the removal of zooids from growth tips; ii) growth and reproductive responses to damage imposed at different locations within the colony and iii) the effects of damage produced by a natural predator the nudibranch Polycera hedgepethi. This dataset gives the growth and reproductive responses of B. neritina colonies over a four week period in February 2000 following three treatments: i) a single predation event by P. hedgepethi; ii) an imitation predation event and iii) no damage. Each of the three experimental treatments was carried out on twenty immature B. neritina colonies under laboratory conditions; the colonies were then returned to the field site at Williamstown, Victoria. Neither predation by P. hedgepethi nor imitation predation resulted in any significant change in growth, onset of reproduction or reproductive output in B. neritina.