“…However, the calculated value for pike IgM is in good agreement with the molecular weights obtained for bony fish immunoglobulins. From the literature it is apparent that bony fishes usually have only one class of immunoglobulins which is tetrameric rather than pentameric (Acton et al, 1971a(Acton et al, , 1971bBradshaw et al, 1971;Clem, 1971;Hall et al, 1973;Litman et al, 1971a;Litman, 1976;Marchalonis, 1971;Pollara et al, 1968;Shelton and Smith, 1970).…”