In 2003, Nasa found freshwater snails reproduced in space with 50% larger statoconia

Nasa researchers observed freshwater snails reproducing in space during a Shuttle mission.

Their gravity-sensing organs, called statoconia, grew substantially larger in microgravity.

Swordtail fish larvae also developed enlarged otoliths, which are similar gravity-sensing stones.

This indicated a critical developmental period where altered gravity impacts stone size.

The findings suggest these organs regulate to achieve a functional weight.