Researchers from Japan have now found how a fish with transparent blood lives in the frigid waters of Antarctica at a depth of 3,300 feet.
The fish, called Ocellated Ice Fish, is unique because it lacks an essential protein in its body that transports blood in all vertebrates. The protein- hemoglobin- also makes the blood appear red in color, reports AFP.
The Tokyo Sea Life Park is the only aquarium in the world that has the Ocellated Ice Fish.
"Luckily, we have a male and a female, and they spawned in January," said Satoshi Tada, an education specialist at the center, reports Discovery News.
Researchers from the Park say that the reasons for the fish living just like any other fish are because it has a larger heart and uses blood plasma to transport the oxygen. Also, the fish lacks scales on its body that helps it to absorb oxygen from its surroundings.
However researchers aren't sure why the fish has no hemoglobin in its blood.
"Why is it the fish lost hemoglobin? More studies are needed on the question," Tada said, reports Independent.co.uk.
The aquarium received the icefish from Suisan Kaisha Ltd. "We asked Nippon Suisan for cooperation in bringing such fish to Japan," said Naoaki Kawahara, a fish keeper at Tokyo Sea Life Park, reports the Japan Times.