Nautilus in Minecraft eat pufferfish, but also accept other fish for healing and breeding. Their favorite food for taming and breeding is pufferfish.
Main food
Nautilus are tamed by feeding them pufferfish, including both regular pufferfish items and buckets of pufferfish. Pufferfish are also what you must use to put two nautilus into “love mode” so they can breed.
Other fish they can eat
Once tamed, nautilus can also be fed other kinds of fish to heal them, such as cod, salmon, and tropical fish (both as items and in buckets). Baby nautilus will eat several fish as they grow, and after consuming enough they automatically become tamed adults.
