Biomphalaria havanensis Identified as a Potential Intermediate Host for the Digenetic Trematode Bolbophorus damnificus

The digenetic trematode Bolbophorus damnificus has been associated with mortalities in commercial channel catfish Ictalurus punctatus in the Mississippi Delta. In the life cycle of B. damnificus, the only confirmed first intermediate host is the ram's horn snail Planorbella trivolvis. Recently, the exotic snail Biomphalaria havanensis has been isolated in several channel catfish ponds in the Mississippi Delta. The aim of this study was to determine whether this invasive snail species could also serve as a first intermediate host in the B. damnificus life cycle. Bolbophorus damnificus ova were collected from an American white pelican Pelecanus erythrorhynchos that had been artificially infected with B. damnificus metacercariae; the ova were then introduced into an aquarium with parasite‐negative B. havanensis. Bolbophorus damnificus cercariae (confirmed by polymerase chain reaction) were detected in B. havanensis 45 d after exposure to B. damnificus ova. The snails continued to shed B. damnificus cercariae throughout the 80‐d postexposure examination period. Before this research, the only reported natural B. damnificus infection of snails involved P. trivolvis. This study indicates that the range of snail hosts is broader than previously suspected. A survey should be implemented to identify additional snail species that can serve as hosts for B. damnificus. Further research should determine whether B. havanensis is a natural host for B. damnificus, and if so the prevalence of B. havanensis in commercial channel catfish ponds should be assessed.