Do you remember the "fish astronauts" who "took" the Shenzhou 18 to space? They are expected to "go on a business trip" to space again this year

Do you remember the four zebrafish that "ridden" the Shenzhou 18 into space?

On April 25, 2024, the Shenzhou 18 manned spacecraft was launched into space. As special tourists, four zebrafish and four grams of fish algae were brought into space by the astronauts, thus successfully starting the journey of "fish farming in space".

It is reported that the "fish astronaut" zebrafish is expected to set off again this year to assist scientists in conducting research on the impact of the space environment on the muscle and bone development of vertebrates.

Zebrafish are tropical freshwater fish native to South Asia. In addition to their ornamental value, they are also the third largest vertebrate model organism after mice and rats. Zebrafish have efficient reproductive capacity. Each female fish lays 200 to 400 eggs each time. It only takes 24 hours for a fertilized egg to develop into an embryo that can swim. The sufficient "samples" provide convenience for genetic screening. At the same time, zebrafish develop through in vitro fertilization, and the early embryos are transparent, which is conducive to scientific researchers to fully observe and study their development process, making them well-deserved "star players" in laboratory research.

In addition, the zebrafish genome and the human genome have a similarity of up to 87%. Experts say that zebrafish are small in size and have characteristics such as in vitro fertilization, in vitro development, and transparent early embryos. Scientists can fully observe and study their developmental process, which is of great significance for understanding human life sciences, disease prevention and treatment, and drug development.

During the Shenzhou 18 mission, scientists simulated the material cycle of the biosphere through zebrafish and duckweed. This was the first time that my country established a self-circulating aquatic ecosystem in orbit, achieving gas balance and long-term stable operation of the aquatic ecosystem. The ecosystem operated stably on the space station for 43 days, setting the international record for the longest time a space aquatic ecosystem has operated in orbit.

It is important to know that the microgravity environment in space affects many functions in the human body, including cardiovascular dysfunction, decreased immune function, bone loss, muscle atrophy, and endocrine disorders. The mechanism of these effects has always been an important topic in the study of space biological effects. As experimental animals, the study of zebrafish in space will help humans to have a more comprehensive and in-depth understanding of the impact of the space environment on genes, cells, and life as a whole, and provide valuable scientific data for future space exploration. Let us look forward to what new gains the "fish astronauts" will bring on their "business trip" this year!

Review: Xinhuanet Science Department