Immune hypersensitivity in the channel catfish, Ictalurus punctatus (Rafinesque)

Channel catfish, Ictalurus punctatus, exhibited passive cutaneous anaphylaxis (PCA) when sensitized with Flexibacter columnaris antiserum produced in channel catfish (the first record of PCA in any fish), but not when sensitized with homologous antiserum against channel catfish virus. Channel catfish did not give delayed skin hypersensitivity responses after immunization with either channel catfish virus or F. columnaris.