| initial steps of speciation by geographic isolation and host switch in salmonid pathogen gyrodactylus salaris (monogenea: gyrodactylidae). | to test the hypothesis that host-switching can be an important step in the speciation of gyrodactylid monogenean flatworms, we inferred the phylogeny within a cluster of parasites morphologically close to gyrodactylus salaris malmberg 1957, collected from atlantic, baltic and white sea salmon (salmo salar), farmed rainbow trout (oncorhynchus mykiss), and grayling (thymallus thymallus) from northern europe. the internal transcribed spacer region of the nuclear ribosomal gene was sequenced for tax ... | 2004 | 15013741 |