An international team of researchers has sequenced the genomes of 24 Antarctic fish species to investigate how they survive the extreme cold. The study, published in the journal Nature Communications, enables understanding of how these fish organisms survive in the subzero Southern Ocean, and sheds light on the evolutionary history of these iconic fish.
Notothenioids are a unique group of fish species. They live in the cold waters below the sea ice of Antarctica, which is largely isolated from the rest of the marine world by a circular current around the continent. The fish are remarkable in many ways. For example they have evolved antifreeze proteins which allow them to survive the water temperatures, which can reach -2°C (28 F) – a pretty hostile environment for most species. One subgroup of notothenioids – called “icefish” – have lost their oxygen-binding haemoglobin proteins and that makes them the only vertebrates known to not have red blood.
British Antarctic Survey (BAS) researcher Professor Melody Clark is a co-author on the paper. She says:
“This is an amazing achievement. The sequencing of so many Antarctic fish genomes will enable us to make real inroads into identifying how these animals manage to survive in such freezing conditions.”
Read more at British Antarctic Survey
Image: Icefish, Chaenocephalus aceratus (Credit: Doug Allan via British Antarctic Survey)