The tadpoles hatched during the last two days from frog eggs fertilised on the ground before flight. They darted, swam rapidly in circles or floated, tails wriggling, inside two experimental flasks. The tadpoles' weightless aquatics were 'certainly not what one would see on Earth', said Ken Souza, a Nasa scientist. 'They were swimming in backwards somersaults, forward somersaults. Some froze, some swam normally. We had a real hodgepodge. . .'
Four South African clawed frogs aboard the space shuttle were injected on Sunday with hormones to induce ovulation. Two frogs then were chosen to provide 600 eggs that were drenched with sperm. Half the eggs were placed on Monday in a centrifuge providing artificial gravity; the others were incubated in the shuttle's normal near-zero gravity. 'It's the first time we've had ovulation (in space) in a higher species,' said Mr Souza. 'We've also had fertilisation. We now know that the eggs can be fertilised in the absence of gravity.'Reuse content