Absence of age-related ploidy changes in a fish with indeterminate growth

We considered the problem of age-related increase in ploidy of liver cells in the oyster toadfish Opsanus tau using a cytofluorometer. Over 90% of toadfish liver cells are diploid, and the ratio of diploid to tetraploid to octaploid cells remains constant in 3- to 11-year-old fish. The absence of ontogenetic increases in ploidy in toadfish, as opposed to mammals, correlates with fish patterns of indeterminate growth and plasticity.