Scientists are Teaching Shrimp to Eat in Microgravity for Future Moon Bases

Overcoming the Constraints of Microgravity Simulation

For years, the prospect of space-based aquaculture has been hindered by the difficulty of testing aquatic life in an environment that mimics the weightlessness of space. Traditional methods, such as parabolic flights and drop towers, provide only seconds of true microgravity, while the International Space Station remains a prohibitively expensive venue for extensive testing. Standard clinostats—devices that rotate samples to negate gravitational effects—typically rotate at 10 to 25 rpm, which is too slow for agile aquatic animals.

To solve this, researchers at the Okayama University of Science engineered a custom, high-speed clinostat capable of rotating at 130 rpm. By spinning more than twice a second, the device prevents juvenile shrimp from righting themselves, creating a sustained microgravity analog.

Feeding Behaviors and Genetic Markers in Crustaceans

The study, which was documented in a paper published in Microgravity Science and Technology, focused on juvenile kuruma shrimp. During the experiments, researchers observed that the shrimp fed most effectively when water flow—caused by the rapid rotation of the clinostat—was minimized.

Beyond physical behavior, the team conducted a Gene Ontology (GO) analysis to determine if the microgravity environment triggered molecular changes. Comparing the RNA of shrimp exposed to 24 hours of simulated microgravity against a control group, researchers noted stark differences in genes linked to the chitin metabolic process and cuticle development. Because these genetic markers are tied to the shrimp’s exoskeleton and locomotion, the findings suggest that microgravity exerts a biological impact on the animals even when they appear to be functioning normally.

Scaling Toward Closed-Loop Space Habitats

To validate their initial observations, the research team expanded their scope to include Artemia, or brine shrimp, which are known for their tolerance to group culturing. The team confirmed that these crustaceans continued to feed on microalgae, specifically Tetraselmis, throughout a continuous four-day rotation in the high-speed clinostat. This success was aided by the use of “Third Water,” a proprietary aquatic medium developed by the university specifically for space-like environments.

The long-term objective is to move beyond terrestrial simulations. The research group is currently developing an aquaculture tank designed for potential installation on the International Space Station. The goal is to create a fully closed, recirculating system capable of maintaining aquatic life for over 100 days without the need for water exchange. As part of this effort, the team is also designing AI-powered organism recognition systems and remote-controlled automatic feeders to minimize human intervention.

While the study provides critical data, some variables remain difficult to isolate. Researchers noted that it is challenging to distinguish whether specific feeding behaviors were a direct result of microgravity or a reaction to the physical turbulence created by the clinostat’s rotation. Despite these limitations, the project establishes a framework for future space-based food production, addressing a fundamental requirement for sustaining human health during long-duration planetary exploration.