The Virginia Institute of Marine Science (VIMS) at William & Mary has found a new species of Antarctic dragonfish in the water near the western coast of the Antarctic Peninsula. The species is called Akarotaxis gouldae, which means “Banded Dragonfish.” It shows how diverse and fragile the Antarctic environment is.
Genetic Analysis and Species Identification
Genetic analysis was the first way that Akarotaxis gouldae was discovered. It was then written about in the journal Zootaxa. At first, larvae found while trawling for zooplankton off the coast of Antarctica were thought to be Akarotaxis nudiceps, a closely similar species of dragonfish.
But when their DNA was compared to Akarotaxis nudiceps specimens from VIMS, Yale University, and the Muséum national d’Histoire naturelle in Paris, France, big differences in mitochondrial gene regions showed that the juvenile samples were from a different species.
Significance of Morphological Examination
The study’s lead author, Andrew Corso, did it while getting his Ph.D. at W&M’s Batten School of Coastal & Marine Sciences at VIMS, with Eric Hilton and Deborah Steinberg as his faculty mentors.
Using the DNA data as a guide, Corso and his colleagues asked for samples of adult Akarotaxis gouldae to be looked at from many fish collections around the world. When the adult samples of the two species were compared, changes in their shapes became clear.
“An adult Akarotaxis gouldae has two clear bands on its sides that are missing from Akarotaxis nudiceps. This is why we were surprised to find that the species was already in collections but had been missed,” Corso said. “In the field of fish taxonomy, genetics alone are being used more and more to tell species apart.”
Also see :- Mysterious Clones: Invasive Jellyfish From China Alarm British Columbia Researchers
Even though genetic testing is very useful, our finding shows how important early life stage morphology and natural history collections are. These can be found at VIMS and other places.
Evolutionary Insights from Genetic Studies
Genetic testing also showed signs of development. Corso and coauthor Thomas Desvignes from the Institute of Neuroscience at the University of Oregon used a method called time-calibrated phylogeny to figure out that Akarotaxis gouldae became a different species about 780,000 years ago. At this point in time, ice covered most of the Southern Ocean.
In this process, the rate of genetic changes is used to figure out how a species evolved, Corso explained. “We think that a group of dragonfish may have become trapped in deep trenches under glaciers, where they can only eat food that the moving ice pushes in.”
When the glaciers went away, this group became different enough from Akarotaxis nudiceps that they could no longer reproduce with each other.
Conservation Concerns for the Newly Discovered Species
At this point, not much is known about Antarctic dragonfish because they live in the faraway Southern Ocean and spend most of their adult lives in deep water. Previous study has shown that these fish protect their nests in shallower coastal waters, and their young stay close to the surface while they are larvae.
Examining the ovaries of females showed that they were not able to reproduce much. Akarotaxis nudiceps is found in the water around the southern continent, but Akarotaxis gouldae seems to only be found in the water around the western Antarctic Peninsula, according to data from larval sampling.
Dragonfish are important food for many animals, including the famous penguins of Antarctica, whose numbers have dropped sharply in recent decades. Corso’s research in 2022 found a link between less ice in the Southern Ocean and rising temperatures and fewer silverfish in the Antarctic.
Corso said, “Akarotaxis gouldae seem to have one of the smallest ranges of any fish that is only found in the Southern Ocean.” “This species’ small range, low ability to reproduce, and the fact that their young live in shallower water all point to it being vulnerable and susceptible to the effects of the krill fishery.”
The Conservation of Antarctic Marine Living Resources (CCAMLR) runs the international Antarctic krill fishery, which focuses on the seas around the western Antarctic Peninsula.
Commercial fishing boats search for krill in water that is 0 to 250 meters deep. CCAMLR stresses how hard it is to correctly identify finfish larvae and juveniles that get caught in these operations.
He said, “Because we don’t know much about this area’s biodiversity, we think that people should be careful when taking resources from it until we know more about how it will affect the ecosystem as a whole.”
Implications of the Discovery and Naming the New Species
The ARSV The name Laurence M. Gould comes from Laurence McKinnley Gould, who was the head scientist on the first trip to Antarctica. Most people would think that Akarotaxis gouldae was also named after the famous geologist, but the researchers chose to name it after the ship and its crew’s important scientific achievements.
Challenges and Future Directions in Antarctic Research
The ARSV From 1997 until its permit was not renewed in April of this year, Laurence M. Gould paid for the U.S. National Science Foundation’s Antarctic Program. It was one of two ARSVs from the United States that were sent to study the Southern Ocean.
The U.S. National Science Foundation said the Gould’s charter was not renewed because of cost concerns and changes in the U.S. Antarctic Program’s study priorities. A new ship is currently being designed.
The ARSV Laurence M. Gould and its crew were very helpful to studies being done in the Antarctic by VIMS and other groups. Steinberg, who is Corso’s advisor, does long-term research on how climate change affects groups of zooplankton around the western Antarctic Peninsula and how those changes affect the marine food web.
For this kind of study to work, samples must be taken at regular times, which can change depending on how many support ships like the Gould are available.
“The loss of the ARSV Laurence M. Gould is a setback for me in my scientific study of the Antarctic,” Corso said. Antarctica is warming up faster than any other place in the Southern Hemisphere.
The area is also home to a huge variety of plants and animals that we are just now starting to learn about. We named this fish after the ship to honor its scientific achievements and bring attention to the fact that more tools are needed to study this unique ecosystem.
