December 29, 2009

See-Through Goldfish Unveiled

Japanese researchers have succeeded in producing goldfish whose beating hearts can be seen through translucent scales and skin, AFP reported.

The development is just one part of efforts to reduce the need for school dissections, which have become increasingly controversial, particularly in schools.

Yutaka Tamaru, an associate professor in the department of life science at Mie University, said the fish allow them to see a live heart and other organs because the scales and skin have no pigments.

"You don't have to cut it open. You can see a tiny brain above the goldfish's black eyes."

Researchers from Mie University and Nagoya University in central Japan produced the "ryukin" goldfish by picking mutant hatchery goldfish with pale skin and breeding them together.

Tamaru told AFP that having a pale color is a disadvantage for goldfish in an aquarium but added that it's good to see how organs sit in a body three-dimensionally.

He said the goldfish are expected to live up to roughly 20 years and could grow as long as 10 inches and weigh more than five pounds -- much bigger than other fish used in experiments, such as zebrafish and Japanese medaka.

"As this goldfish grows bigger, you can watch its whole life," said Tamaru.

Additionally, see-through frogs first developed by a team of researchers in 2007 are about to hit the open market.

The researchers plan to start selling the four-legged creatures, whose skin is transparent from the tadpole stage.

Masayuki Sumida, professor at the Institute for Amphibian Biology of Hiroshima University, said they are making progress in their mass-production and are likely to put them on the market next year.

Sumida's team produced the creature from rare mutants of the Japanese brown frog, or Rena japonica, whose backs are usually ochre or brown. Two kinds of recessive genes have been known to cause the frog to be pale.

The see-through tadpoles and adult frogs would be available in the first half of next year in Japan for laboratories and schools and as pets, with a price tag expected to be below $110 dollars each, according to Sumida.

The creatures are also expected to be sold abroad.

In the meantime, animal rights activists have pressed for humane alternatives to dissections, such as using computer simulations.

Sumida said that while goldfish are easier to keep, frogs are higher forms of life and therefore preferable for experiments.


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