The publication described this as a significant achievement in space ecological experiments, emphasizing its importance in advancing space ecosystem technologies and offering critical data for future closed-loop space systems.
On April 25, the Shenzhou-18 manned spacecraft carried four zebrafish, four grams of aquatic plants, and three Chinese astronauts into space. Upon their return on November 4, the crew brought back water samples from the space-based ecosystem.
Fish adaptation in microgravity presents unique challenges. Researchers from the Institute of Hydrobiology (IHB) of the Chinese Academy of Sciences (CAS), along with the Shanghai Institute of Technical Physics, collaborated on this experiment. The system utilized photosynthetic aquatic plants to generate oxygen for the fish, while zebrafish waste provided nutrients to support the plants. Food was administered via a syringe, explained the IHB.
Zebrafish, with a body length of 3 to 5 cm and the ability to lay over 300 eggs at a time, share more than 70% genetic similarity with humans, making them valuable for studying disease pathogenesis and drug development, noted IHB researcher Wang Gaohong.
Astronauts observed and collected water samples and restocked food during the mission. Wang noted the zebrafish exhibited atypical behaviors, including upside-down swimming and looping, due to microgravity effects.
Sun Yonghua, also from the IHB, highlighted the experiment's success as a foundation for future vertebrate studies and potential space medical research. The returned samples are now stored in ultra-low temperatures for further study.
Currently, over 500 laboratories in China are engaged in zebrafish research.
