Seasonal Variation in Channel Catfish Virus Antibody Titers in Adult Channel Catfish

Abstract

Abstract Serum antibody titers for channel catfish virus (CCV) were measured in adult channel catfish (Ictalurus punctatus) that had survived an epizootic of channel catfish virus disease (CCVD) as fingerlings. Serum antibody titer data were grouped into four categories for statistical analysis based on the following titer levels: < 1, no titer; 1-10, low; 10-30, medium; and > 30, high. Significantly lower antibody titers were observed in January and April than in July and October. The increase in the number of high titers concurrent with elevated water temperature may indicate the existence of carriers persisting 4 years after the original epizootic. Based on the findings of this study, success in isolating CCV from channel catfish during colder months of the year may be enhanced, in part, by the low immune status of the fish at this time.