INTRASPECIFIC VARIATION OF TAENIA-TAENIAEFORMIS AS DETERMINED BY VARIOUS CRITERIA

The intraspecific variation of four laboratory-reared isolates of Taen ia taeniaformis the SRN and KRN isolates from Norway rats, Rattus norv egicus, captured in Japan and Malaysia, respectively; the BMM isolate from a house mouse, Mus musculus, captured in Belgium; and the ACR iso late from a gray red-backed vole, Clethrionomys rufocanus bedfordiae, captured in Japan was examined by various criteria. Eggs of each of th e four isolates were orally inoculated into several species of interme diate host. They were most infective to the rodent species from which the original metacestode of each isolate had been isolated in the fiel d, and only the ACR isolate was infective to the gray red-backed vole. Although little difference was found between the SRN, KRN, and BMM is olates by the other criteria, including the morphology of rostellar ho oks, the protein composition of the metacestode, and restriction endon uclease analysis of DNA, the ACR isolate was clearly different from th e others. It was considered that the ACR isolate was independent as a strain distinct from the other three isolates.