|Ben-horin, Tal - University Of Rhode Island|
|Allen Jr., Standish - Virginia Institute Of Marine Science|
|Small, Jessica - Virginia Institute Of Marine Science|
Submitted to: Marine Ecology Progress Series
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2018
Publication Date: 4/26/2018
Citation: Ben-Horin, T., Allen Jr., S., Small, J., Proestou, D.A. 2018. Genetic variation in anti-parasite behavior in oysters. Marine Ecology Progress Series. 594:107-117. https://doi.org/10.3354/meps12511.
Interpretive Summary: The objective of this study was to characterize eastern oyster phenotypes resistant to Dermo disease and identify potential mechanisms contributing to resistance. Three oyster families developed at the Aquaculture Genetics and Breeding Technology Center were exposed to the Dermo-causing parasite in the laboratory and monitored for survival and changes in parasite density. Variation in resistance was detected. Oysters from the same three families were subsequently subject to feeding experiments in the presence and absence of the parasite to determine whether behavioral avoidance contributes to the observed variation in resistance. Feeding behavior in the absence of the parasite did not vary among the families; however, parasite exposure resulted in significantly reduced particle clearance rates for the two resistant families while feeding behavior in the susceptible family was unchanged. Our results suggests that reduced feeding behavior is a component of the Dermo-resistant phenotype in eastern oysters. These findings have important implications for oyster breeding strategies and industry practices.
Technical Abstract: Behavioral avoidance of disease-causing parasites provides a first line of defense against the threat of infection, particularly when hosts are exposed to free-living parasite stages in the external environment. We report that 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.