Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

High frequency of deformations in Dolly Varden charr (Salvelinus malma, Walbaum, 1792), an introduced population.

Abstract

The incidence of deformities in introduced Salvelinus malma from the Obukaruishi and Notto rivers in the western part of Hokkaido, Japan, was studied in October-November 2014, sixty years after the species was introduced. It was shown that the frequency of fin deformities in the fish was significantly higher in the Obukaruishi River than in the Notto River. Deformities were observed in all seven fins in the Obukaruishi River, whereas deformities were not observed in the dorsal or in either of the two ventral fins in fish from the Notto River. The frequency of deformities was highest in the anal fin in fish from the Obukaruishi River (36%) and in the caudal fin of fish from the Notto River (27%).