ATTACHMENT BEHAVIOR IN THE BARNACLE BALANUS-AMPHITRITE AMPHITRITE (DARWIN) - GENETIC AND ENVIRONMENTAL-EFFECTS

The occurrence of "fatal errors" in settlement (Strathmann et al., (1981)) suggests the possibility of natural selection for habitat choice by settling larvae of sessile marine invertebrates. The effectiveness of this selection depends upon the amount of additive genetic variation present for habitat choice. A sib analysis was used to assess genetic and environmental variation in the response of Balanus amphitrite cyprids to two surface treatments, a glass "control" surface and glass modified by adsorption of a settlement-inducing pheromone. The pheromone treatment caused a significant increase in the percentage of B. amphitrite cyprids attaching to the surface of assay tubes. Attachment to glass and pheromone-treated surfaces was significantly positively correlated. The sib analysis of cyprid response to the two surface treatments revealed no effect due to male parent, and therefore little or no additive genetic variation in cyprid attachment behavior, but a highly significant effect due to the female parent. Further analysis indicated that part of the female effect could be explained by temporal variation in larval culture conditions (glass and pheromone surfaces) and part by maternal and/or nonadditive genetic effects (glass surfaces only). These results suggest that barnacle settlement behavior may be quite plastic in nature and that planktonic factors, already implicated in larval survival and dispersal, may also affect habitat choice at settlement. © 1990.