CRYPTOCARYON IRRITANS (CILIOPHORA) - ACQUIRED PROTECTIVE IMMUNITY IN THE THICK-LIPPED MULLET, CHELON LABROSUS

Acquired protection to Cryptocaryon irritans has been demonstrated for the first time, using the grey mullet, Chelon labrosus, as an experim ental host. Fish, immunized by controlled infections, established immu nity against challenge infections with C. irritans, the degree of prot ection correlating with both intensity and exposure levels, with relat ively few fish developing full protection. Protection lasted for six m onths in the absence of reexposure to the parasite. There was no evide nce of cross-protection in mullet against infection with the closely r elated fish parasite, Ichthyophthirius multifiliis. (C) 1995 Academic Press Limited