Genetic variation in anti-parasite behavior in oysters

ABSTRACT: Behavioral avoidance of disease-causing parasites provides a first line of defense against the threat of infection. We report that the suspension-feeding oysters Crassostrea virginica respond to the presence of the water-borne parasite Perkinsus marinus by increasing the rate of shell closure and decreasing the clearance of suspended particles from the surrounding seawater. The extent of feeding behavior modification varied among selectively bred oyster families, indicating genetic variation in this trait. Oyster families susceptible to P. marinus infection were less likely to modify their feeding behavior when this parasite was present, if at all. Characterizing the role of anti-parasite behavior in minimizing P. marinus proliferation in oysters and the implications of variability among individuals will refine our understanding of mechanisms of disease resistance in suspension-feeding bivalves.