Several sea animals have more than one “brain,” but the best‑known example is the octopus, which has a central brain plus a separate cluster of neurons (a “mini‑brain”) in each of its eight arms.
Octopus
An octopus has one main brain in its head and eight additional neural ganglia, one in each arm, so its nervous system is highly distributed. Each arm can process information and control movement semi‑independently, which is why an octopus can coordinate very complex tasks with all its limbs at once.
Other sea creatures
- Cuttlefish have a large central brain plus additional neural clusters in their arms, supporting rapid color change and complex behavior.
- Squid have a main brain and very large optic lobes that act like additional specialized “brains” for vision.
- Starfish lack a single central brain, but have a nerve ring and radial nerve nets in each arm, so control is spread out rather than in one place.
So, if the question is “which sea creature has more than one brain,” the usual answer is the octopus, though several other marine animals also have distributed or multiple brain‑like centers.
