Comparal ve susceptibility of three species of char and of rairbow trout x char triploid hybrids to several pathogenic salmonid viruses

T n p l o ~d hybnds were obtained from rainbow trout Oncorhynchus mykiss females crossed w t h sires of brook trout Salvehnus fontinalis arctic char S alpinus and lake trout S namaycush following heat-shock-provoked retention of the second polar body Survlval rates of h y b r ~d s obtained were ca 50 % The hybnds and the parental specles were challenged with infect~ous pancreatic necrosls vlrus (IPNV) type Sp viral haemorrhagic septlcaem~a vlrus (VHSV) types 1 and 3 and lnfect~ous h a e m a t o p o ~e t ~c necrosis vlrus (IHNV) Ra~nbow trout X coho salmon ( 0 h s u t c h ) t n p l o ~d hybnds were included in certain infection t i ~a l s The results Indicated that brook trout were reslstant to VHSV and brook trout X ralnbow trout hybnds were reslstant to both VHSV and IHNV but suscept~ble to IPNV Arct~c char were susceptible to IPNV and resistant to VHSV The hybnds were suscept~ble to IPNV, but part~ally reslstant to VHSV Lake trout were partially resistant to IPNV but their hybnds w t h ralnbow trout were susceptible Lake trout infected by VHSV showed c l ~n ~c a l slgns and sign~ficant losses resulted