Researchers lowered a camera to a depth of 535 meters beneath the cold waters of Antarctica and accidentally stumbled upon a huge colony of icefish. Across an area of at least 240 square kilometers, they found about 60 million nests where the fish raise their offspring, infohub.kz reports.
Scientists were studying the Weddell Sea from the German icebreaker Polarstern. They were conducting another study and using a camera to survey the seafloor. At some point, they noticed that round icefish nests kept appearing again and again on the recordings. The further they explored the area, the more such nests they found.
Each nest is about 75 cm in diameter: the fish clear a small depression in the bottom, fill it with small stones, and lay their eggs there. On average, a nest contains about 1,735 eggs, and an adult fish usually "stands guard" nearby.
These are unusual Antarctic icefish, Neopagetopsis ionah. They lack normal hemoglobin and mature red blood cells. They have adapted to extract oxygen directly from the cold water, and special protein compounds protect their bodies from freezing.
Scientists believe the fish did not choose this location by chance. A deep-water current passes through there, and the water temperature near the bottom is about 2 °C higher than in neighboring areas. These conditions may help the fish reproduce. Such multimillion-strong colonies are also important for other animals. Weddell seals regularly dive to these depths, so icefish likely become part of their diet.
Earlier, Kursiv LifeStyle wrote that American biologists discovered a new species of blind cavefish in a cave in the state of Alabama, nicknamed the "demon fish." According to scientists, it may be one of the rarest fish in the world.