| dc.description.abstract | The taxonomic status of the three nototheniids, Lepidonotothen squamifrons, L. larseni and
Gobionotothen marionensis from different localities in the Southern Ocean is re-evaluated at the
DNA level. DNA sequence divergences and phylogenetic relationship were estimated using a
combined mitochondrial (mtDNA, ND2 and COI) dataset and data for one nuclear gene (S7 intron
1). Phylogenies of both datasets had Lepidonotothen kempi nested within L. squamifrons lineage,
with low sequence divergences (0% to 0.4%) between the two nominal species suggesting that they
are populations of one species. Therefore, these results do not support the previous splitting of L.
squamifrons into different species. Similarly, the L. larseni specimens also represented a single
genetic unit (0.3% to 0.6%) with low geographic variation between Atlantic and Indian Ocean
specimens, which does not support the splitting of this species into geographically restricted
species. The mtDNA phylogeny clearly separated individuals of G. acuta from Kerguelen, Heard
and MacDonald Islands from G. marionensis individuals into different clades, with sequence
divergence of 2.9% between these clades supporting they are different species. | |
