Isolated and shrouded in darkness, we're often reminded that humans know more about space than we do the deepest regions of the oceans here on Earth. The icy depths hide a wealth of bizarre, almost inexplicable creatures from the giant squid to zombie worms feasting on whale carcasses, but one newly discovered life form has scientists truly stumped: a scaleless fish with transparent blood.
When Japanese krill fisherman recently found an Ocellated Ice Fish (Chionodraco rastrospinosus) in the Antarctic Ocean, researchers were astounded. With no scales, or hemoglobin in its veins, the fish has utterly perplexed scientists. Animals with bones require hemoglobin, it's the protein that gives blood its red color and spreads oxygen throughout the body. So how does the Ocellated Ice Fish survive without it?
Experts at the Tokyo Sea Life Park studying a pair of the fish - the only known specimens currently in captivity - admit they know very little about the fish.
"Luckily, we have a male and a female, and they spawned in January," said Satoshi Tada, an education specialist at the center. Tada added that scientists hope to acquire more mature specimens of the fish to adequately study their mysterious physiology and uncover the magic behind their many secrets.
Tada and his team of researchers believe the fish may be a product of evolution that possibly developed by living near deep sea vents as far as to 3,200 feet below the surface of the ocean. They theorize that the Ocellated Ice Fish is able to live without hemoglobin due to a particularly large heart, and that the creature uses plasma in place of hemoglobin to transport oxygen around its body. With no scales to provide any kind of armor, researchers also think the fish absorbs oxygen through its skin.
However, just how or why the fish has evolved to live with clear blood continues to elude scientists.
Specialist Tada says the center hopes the pair of recently mated Ocellated Ice Fish and their children will provide science with the answers to these lingering questions.
"Why is it the fish lost hemoglobin? More studies are needed on the question," Tada said.