Papillomatous growth in sole from Wakasa Bay area

SummaryA preliminary survey for tumorbearing fish among sole caught in waters of Wakasa Bay area, Japan was carried out. Five sole, one Limanda herzensteini and 4 Hippoglossoides dubius, with skin tumors were obtained. Histological observations of the lesions in both species revealed marked proliferation of epithelial elements accompanied with increase in fibrous structure of connective tissue. In addition marked increase of melanin-containing cells was observed in tissue sections of growth of L. herzensteini with darker appearance. The gross and microscopic findings of H. dubius resembled descriptions of the epithelial papillomas reported by other authors to occur among flathead sole populations near Friday Harbor, Washington.