Australian lungfish has largest genome of any animal sequenced so far The Australian lungfish has the largest genome of any animal so far sequenced. Siegfried Schloissnig at the Research Institute of Molecular Pathology in Austria and his colleagues have found that the lungfish’s genome is 43 billion base pairs long, which is around 14 times larger than the human genome. Its genome is 30 per cent larger than that of the previous record holder: the axolotl, a Mexican amphibian that the team sequenced in 2018. The new genomic analysis shows unequivocally that lungfish are more closely linked to the evolutionary line that gave rise to four-legged animals. Coelacanths diverged earlier, while lungfish branched off 420 million years ago. “In order to get out of the water, you need to adapt towards a terrestrial lifestyle,” says Schloissnig. “You have to be able to breathe air, you have to be able to smell.” The Australian lungfish is similar to amphibians when it comes to the raw number of genes associated with the development of lungs and articulated limbs, as well as the detection of air-borne smells. “When you look at it from a genomic perspective, it is genomically halfway between a fish and a land-based vertebrate,” says Schloissnig.