A transparent goldfish that reveals its inner organs has been developed by a joint research team of Mie University and Nagoya University in Japan.

The aim of the project was to create a transparent fish that makes it possible for researchers to study blood constituents and organ behaviour without having to dissect the animal. Unlike ordinary goldfish variants, this type has therefore been made really big and can weigh up to 1 kg. Up until now, the transparent fish of choice for researchers have been the see-through zebrafish, but this tiny fish only weigh abut 3 grams and is therefore much more difficult to study than the 1 kg goldfish.

The translucent goldfish was developed in just three years by repeatedly letting selected pale goldfish specimens mate with each other.

“Pale-colored goldfish have little commercial value, but their negative value has turned into a positive,” said Mie University Associate Professor Yutaka Tamaru.

The creation of a transparent goldfish was announced Wednesday last week at the annual meeting of the Molecular Biology Society of Japan.