Muscle myogens in the New Zealand Galaxiidae

The muscle myogen proteins of 10 species of the family Galaxiidae exhibited a high degree of species specificity when separated by starch gel electrophoresis. Non‐diadromous, non‐lacustrine species had some variation in the proteins present, while diadromous and lacustrine species, except for Galaxias maculatus, had remarkably uniform muscle myogen electrophero‐grams. The variation can be explained by polymorphism and mosaic evolution of isolated freshwater populations. It was found that previously erected specific and generic categories, except for G. vulgaris, are clearly defined by differences in muscle protein. The standardised electropherogram types obtained were subjected to cluster analysis using both squared Euclidean distance and the complement of Jacard's coefficient with average sorting strategy. A principal component analysis was also carried out. The first two components of the principal component analysis widely spaced the three genera included in this study (Salmo, Galaxias, and Neochanna), with N. burrowsius occupying an intermediate position between Galaxias and Neochanna. Previous workers have considered this species to be a connecting link between the two genera. The dendrogram produced by using squared Euclidean distance (which included all available information) first clustered the types into Salmoniidae and Galaxiidae. The latter were split into the genus Neochanna and the genus Galaxias which was then subdivided into stout‐bodied species (G. argenleus and G. jasciatus) and slender‐bodied species. G. brevipinnis and G. vulgaris types were further separated from the three alpine Galaxias species and G. maculatus. The substantial agreement of these results with previous taxonomic efforts indicates that electrophoretic data can be a valid taxonomic tool.