Significance of the discovery of the new Antarctic dragonfish Akarotaxis gouldae: how biodiversity conservation depends on protecting vulnerable ecosystems

New species of Antarctic dragonfish, Akarotaxis gouldae, has been discovered in the cold waters of the western Antarctic Peninsula, highlighting exceptional sensitivity and insufficiently explored diversity of the Antarctic ecosystem. Scientists named this fish after the research vessel ARSV Laurence M. Gould, which provided support for Antarctic research for decades before being retired from service. This discovery is not only an important step in understanding the biological diversity of the region but also a reminder of the climate threats looming over the Antarctic ecosystem.

The first traces of the existence of this new species were found during genetic analysis of larvae collected from the seas around Antarctica. Although these larvae were initially thought to belong to the species Akarotaxis nudiceps, further DNA analysis revealed clear genetic differences showing that it is a separate species. To confirm this discovery, scientists analyzed adult specimens stored in numerous global natural history collections. Only then did the physical differences between these two species become apparent, including the presence of two stripes on the sides of adult specimens of Akarotaxis gouldae, which are missing in Akarotaxis nudiceps.

Using the technique of time-calibrated phylogeny, researchers estimated that Akarotaxis gouldae diverged as a distinct species about 780,000 years ago, at a time when most of the Southern Ocean was covered by ice sheets. This isolation in deep-sea trenches allowed the fish to evolve into a unique species, and with the retreat of the glaciers, the subpopulations evolved so differently that they were no longer compatible with Akarotaxis nudiceps.

What makes this species particularly vulnerable is its limited distribution range. While Akarotaxis nudiceps is present throughout the southern continent, Akarotaxis gouldae is found exclusively in the waters of the western Antarctic Peninsula. Their reproductive capacity is very limited, which further contributes to the species' vulnerability, especially in light of the increasing pressure from commercial krill fishing, a key link in the Antarctic ecosystem. Krill is fished at depths of up to 250 meters, and there is often incidental capture of younger fish, including Akarotaxis gouldae, further threatening this already sensitive species.

Dragonfish like Akarotaxis gouldae play a crucial role in the Antarctic food chain, being important prey for many species, including Antarctic penguins. Unfortunately, penguin populations have drastically decreased in recent years due to climate change, including ocean warming and ice loss, leading to a significant decline in Antarctic silverfish populations, a crucial food source for many predators.

Although Akarotaxis gouldae has only recently been recognized as a separate species, its presence in global collections shows that it has long been present but overlooked. The research vessel ARSV Laurence M. Gould, after which the fish is named, played a key role in studying this area, allowing researchers to collect valuable data on changes in marine ecosystems caused by climate change.

The vessel ARSV Laurence M. Gould was retired from service in 2024, after more than two decades serving the U.S. Antarctic Program. Although the ship has been replaced, its retirement marked a milestone in Antarctic research, particularly in light of the accelerating warming of Antarctica, which is now warming faster than any other region in the southern hemisphere. Researchers emphasize the importance of continuing research and conservation of the Antarctic ecosystem, especially in the context of climate change that significantly impacts the sensitive biodiversity of this area.

Source: Virginia Institute of Marine Science