February 11, 2008

Fish Taking Part in Zero-gravity Research

In an attempt to find answers about motion sickness, scientists intend to launch 60 tiny fish on a zero gravity rocket ride from above the Arctic Circle on Monday.

Tomas Hedqvist, project manager for Sweden's Esrange Space Centre, told Reuters that the baby cichlid fish will head 260 km (160 miles) into the air on an 11-metre (36-foot) two-stage rocket, where they will experience six minutes of weightlessness.

Experimenters Reinhard Hilbig and Ralf Anken of the University of Stuttgart-Hohenheim in Germany plan to use six video cameras on the fish to judge their reaction.

"Fish, when they get motion sick, begin tumbling around, swimming in circles and miss their balance," he said, adding that some fish do not suffer from motion sickness and seem to adapt quickly to a changed environment.

Some of the fish will be housed in a slowly turning centrifuge which will offer some gravity while others will be in a pure zero G state, Hedqvist said.

By examining the collected video and the small balance organs, called otoliths, which exist naturally in the heads of each fish, scientists hope to discover what makes some sick and others not.

"People when they are aboard the space shuttle they have this space motion sickness also. Human beings have blood pressure up in the head when they are weightless and also bones get weak and muscles get small," Hedqvist said.

"They use fish since it's much easier to investigate on fish (than) human beings."

Earlier related experiments sent cichlid fish on parabolic plane rides -- which involve a steep ascent followed by a plunge -- but Hedqvist said these only offered 20-30 seconds of weightlessness and were too short for clear conclusions.