Infections of the Hemoflagellate, Cryptobia salmositica Katz, 1951, in Freshwater Teleosts of the Pacific Coast

Abstract

Infections of Cryptobia salmositica Katz, 1951, are common and widely distributed in freshwater teleosts of the Pacific coast from southern British Columbia to northern California. The hemoflagellates are reported from 16 species of fish, representing four families and including 10 new hosts. The most susceptible hosts, as indicated by the incidence and intensity of infection, are the pink (Oncorhynchus gorbuscha) and coho (O. kitsutch) salmon, the torrent (Cottus rhotheus) and coastrange sculpin (C. aleuticus), and the longnose dace (Rhinichthys cataractae). The infected fish are typical cold-water species, occurring only in streams of generally low temperatures, graveled beds, and moderate to swift flowing currents. In this natural environment, the fish are associated with Piscicola salmositica (Meyer, 1946), the only known leech vector of the hemoflagellates. It is suggested that but one distinct species, C. salmositica, occurs in the blood of the various teleost fishes in this geographically restricted area in association with a common vector.