This photo taken on April 25, 2024 shows a backup version of the aquatic ecosystem. The three taikonauts aboard China's Shenzhou-18 spaceship have entered the country's space station and met with another taikonaut trio on Friday, starting a new round of in-orbit crew handover.

 

A unique task for the taikonauts of Shenzhou-18 is to create an "aquarium" and raise fish in zero gravity.

 

They will create a simplified version of an aquatic ecosystem using zebrafish and algae to study how the space environment affects their growth and system balance. (Xinhua/Jin Liwang)