Last week, Japan's Tokyo Sea Life Park unveiled its latest exhibit - A transparent fish that has no scales and clear blood. The specimen of the Ocellated Ice Fish, believed to be the only one of its kind in captivity, was brought to the center by Japanese krill fisherman in 2011.
While transparent fish and even animals are not unusual, one with just 1% hemoglobin (compared to 45% in most animals), the protein that carries the blood around the body and gives it the distinct red color, is unheard of. The experts at the aquarium that have been observing the two specimens since they were brought in say that they seem to living, just like any other fish.
Researchers speculate that the Ice Fish is able to survive without the protein partly due due to its larger heart and partly because of its ability to use blood plasma to circulate oxygen through the body. They also believe that the scale-less skin allows the fish to absorb oxygen directly from the depths of the freezing Antarctic waters that they inhabit.
However, there still remains the question of why the fish lost hemoglobin. That, is what Satoshi Tada and other experts at the Sea Life Center are most intrigued about. Luckily for them, the fishermen grabbed a male and female specimen which spawned in January - This means that the experts will have plenty of time and fish, to figure out the mysteries pertaining to the Ocellated Ice Fish.
Resources: independent.co.uk, dailymail.co.uk