Japanese researchers are exploring alternative protein sources for aquaculture feed, such as mushrooms, due to rising costs, sustainability concerns, and supply chain issues related to traditional fishmeal. In addition to mushrooms, other options like insects, single-celled organisms, and citrus by-products are also being experimented with. Preliminary tests have shown positive results in feeding African catfish with mushroom-based pellets, and a trial in Japan found that substituting mushrooms for aquafeeds increased net income.