Ocellated Ice Fish In Japanese Aquarium Has Clear Blood
April 7, 2013

Unique Species Of Arctic Fish Has Clear Blood And No Scales

redOrbit Staff & Wire Reports - Your Universe Online

An unusual species of fish caught in the Antarctic Ocean two years ago has no scales and completely transparent blood, according to experts at Japan´s Tokyo Sea Life Park.

The aquarium is the only place in the world that currently has the unusual creature, which is known as the Ocellated Ice Fish, in captivity. Researchers there say that the fish has clear blood because of it lacks hemoglobin — the protein which gives blood its reddish color and carries oxygen throughout the body.

The Ocellated Ice Fish is the only vertebrate on Earth that lacks hemoglobin, Tokyo Sea Life Park researchers told AFP on Friday — and on top of that, it has no scales either. Little is currently known about the fish, but experts at the facility are hoping to change that in the near future.

“Luckily, we have a male and a female, and they spawned in January,” Satoshi Tada, an education specialist at the aquatic park, told reporters. He explained that having more examples of the creatures might help them discover more about the fish.

Experts at the park believe that the fish can survive without hemoglobin because of its large heart, and because it uses blood plasma in order to circulate oxygen through its system. They also believe that it can absorb oxygen from the waters of its native Antarctic Ocean, where it lives at depths exceeding 3,000 feet. The reason for the lack of hemoglobin remains a mystery that can only be solved by additional research, Tada said.

Officials at the facility initially launched plans to acquire and exhibit the ice fish after learning that krill fishermen occasionally catch species of the fish alive during their trips to the Antarctic, Hisashi Sasaki of Japan Times explained. They contacted a group of fishermen and requested their assistance in obtaining the specimen that are currently on display at the park.

“Aquarium officials were sent 13 fish from five species from a Nippon Suisan fishing vessel in Punta Arenas near the southern tip of Chile in August 2011. The 70-hour transportation of the fish to Japan involved stops in Santiago and Toronto,” Sasaki said.

“The water temperature in the container needed to be kept below 3 degrees so the fish could survive, but had dropped to minus 1.9 degrees,” he added. Nine of the fish died when the container had to be opened and the water changed in Santiago, but four of the fish — including both icefish — survived and were safely delivered to Tokyo.