Karyotypic and taxonomic diversity of the notothenioid fishes of the suborder Notothenioidei (Perciformes) of the Southern ocean
A karyological examination of 61 species (49% of the total number known) belonging to 8 families of the suborder Notothenioidei revealed a high order of karyotypic heterogeneity (2<i>n</i>=20-58, <i>NF</i>=40-88). It has been determined that of these, three species have an ancestral generalised state (2<i>n</i>=48, <i>NF</i>=48). The results indicate that there are 3 evolutionary lines of change in the chromosome karyotype morphology without any increase or decrease in the chromosome number. It is shown that in the families Nototheniidae and Bathydraconidae, there is a characteristically large variability in the karyotypes. On the other hand, in Channichtyidae, a significant taxonomic variability is not in accord with the karyological variability which can be explained by the varied rate of morphophysiological and karyological evolution. The greatest karyotypic variability is found in those species which occur on the Antarctic shelf with its attendant islands and least variability in species on the periphery of the Antarctic region.