A turbot, Scophthalmus maximus, fin (TF) cell line was established and susceptibility to turbot reddish body iridovirus (TRBIV) was determined in this study. Primary culture of TF cells was initiated from fin tissue pieces partially digested with trypsin, collagenase II and hyaluronidase. Digested tissue pieces were cultured at 24 degrees C in Leibovitz-15 medium (pH 7.2), supplemented with 20% fetal bovine serum, carboxymethyl chitosan, N-acetylglucosamine hydrochloride, basic fibroblast growth factor and epidermal growth factor. The cultured TF cells, in fibroblast shape, proliferated to 100% confluency 50 days later. A TF cell line, with a population doubling time of 45.6 h at passage 80, has been established and subcultured to passage 133. Chromosome analyses indicated that the TF cells exhibited chromosomal aneuploidy with a modal chromosome number of 44 which displayed the normal diploid karyotype of S. maximus at least up to passage 80. TRBIV susceptibility testing demonstrated that cytopathic effect and propagated viral particles were observed in TF cells after TRBIV infection. In conclusion, a continuous TRBIV susceptible TF cell line has been established successfully, and the cell line may serve as a valuable tool for studies of cell-virus interactions and has applications for different kinds of cytotechnological studies as well.