GENETIC AND MORPHOLOGICAL STUDY OF THE BLACK-STRIPE MINNOW, GALAXIELLA NIGROSTRIATA (SALMONIFORMES GALAXIIDAE), INCLUDING A DISJUNCT POPULATION NEAR PERTH, WESTERN AUSTRALIA

WA Museum Records and Supplements | Updated 5 years ago

Abstract - This study was undertaken to measure the relatedness of an outlying population of Black-stripe minnow, Galaxiella nigrostriata (Shipway), from Melaleuca Park, 25 km northeast of Perth, to the main populations situated some 350 km to the south between Augusta and Albany. AlIozyme electrophoresis was used to assess genetic divergence between populations. Univariate statistical tests were employed to compare the morphology of fish from the different locations. Reproductive isolation of G. nigrostriata at EPP 173 has resulted in inbreeding and reduced heterozygosity as well as differences in morphology. Galaxiella nigrostriata throughout its range shows
unusually low levels of genetic polymorphism. One polymorphic locus was identified from the 27 loci sampled. Polymorphic individuals were restricted to the southern sites; specimens from EPP 173 were entirely monomorphic. Fish from EPP 173 had longer head lengths and shorter caudal peduncles than those in the south.

Keywords: freshwater fish, low genetic variation.