Abstract:

As an important part of the Antarctic Ocean ecosystem, Antarctic fish play a role in material cycling
and the energy flow within the food web. Individual Antarctic fish specimens were collected from the sea
adjacent to Yelcho Station during the 32nd Chinese National Antarctic Research Expedition, and morphological
analysis and DNA barcoding were employed in their identification. After running blast searches in
NCBI, sequence similarity results showed that only two individuals were identifiable to the species level,
while six individuals were unmatched. Combined with a homologous sequence from GenBank, phylogenetic
analysis was performed and four groups were unambiguously identified from the NJ tree. There was clear
overlap (barcoding gap) between intraspecific and interspecific variabilities in each species, as the smallest
interspecific divergences were well below 2%, while the largest intraspecific divergences were above 2%.
Three valid species were detected from eight individuals, encompassing seven Nototheniidae fish and one
Harpagiferidae fish. Finally, all results further confirmed that notothenioid fish were dominant in terms of
species diversity and biomass in the investigated seas.

Key words: Nototheniidae, DNA barcoding, sequence similarity, barcoding gap, genetic distance