title: Morphologic, Pathologic, and Genetic Investigations of Bolbophorus Species Affecting Cultured Channel Catfish in the Mississippi Delta.
abstract: Trematodes belonging to the genus Bolbophorus have recently been reported as the cause of substantial morbidity and mortality in cultured channel catfish Ictalurus punctatus in Mississippi and Louisiana. Previous investigators identified only a single species, B. confusus. In this investigation, genetic techniques were used to identify all stages of the parasite in all of its hosts. The 18s rRNA genes from specimens collected in Mississippi were sequenced and compared; this analysis revealed that there are two distinct species, B. damnificus (previously identified as B. confusus) and another, undescribed species. (Phylogenetic analysis indicated that a third species, B. levantinus, is also closely related to the Mississippi species.) Species-specific polymerase chain reaction assays capable of identifying and differentiating between these two parasites were developed. Both species were found to infect the first intermediate host (the ram's horn snail Planorbella trivolvis) in commercial channel catfish ponds, but only B. damnificus was recovered from the fish themselves. The new, unidentified Bolbophorus species was determined to be highly pathogenic to a number of fish species. The contribution of B. damnificus to disease in cultured channel catfish remains undetermined. Future investigations of these parasites must now take into account the presence of two distinct species.
authors.affiliation: a North Carolina State University, College of Veterinary Medicine , Raleigh , North Carolina , 27606 , USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Levy
authors.affiliation: a North Carolina State University, College of Veterinary Medicine , Raleigh , North Carolina , 27606 , USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Flowers
authors.affiliation: a North Carolina State University, College of Veterinary Medicine , Raleigh , North Carolina , 27606 , USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Poore
authors.affiliation: a North Carolina State University, College of Veterinary Medicine , Raleigh , North Carolina , 27606 , USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Mullen
authors.affiliation: b College of Veterinary Medicine, Mississippi State University , Mississippi , Mississippi State , 39762 , USA.
authors.forename: L H
authors.initials: LH
authors.lastname: Khoo
authors.affiliation: b College of Veterinary Medicine, Mississippi State University , Mississippi , Mississippi State , 39762 , USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Pote
authors.affiliation: c Department of Animal Sciences , Faculty of Agriculture, Hebrew University , Jerusalem , Rehovot , 76100 , Israel.
authors.forename: I
authors.initials: I
authors.lastname: Paperna
authors.affiliation: c Department of Animal Sciences , Faculty of Agriculture, Hebrew University , Jerusalem , Rehovot , 76100 , Israel.
authors.forename: R
authors.initials: R
authors.lastname: Dzikowski
authors.affiliation: d National Oceanic and Atmospheric Administration, National Ocean Service , Beaufort , North Carolina , 28516 , USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Litaker