Here's why:
* They're highly aggressive and territorial: Figure 8 puffers are known for their aggressive nature and territorial behavior. They will often attack and kill smaller fish, even if they're not considered food.
* They require specific water parameters: They need brackish water, which is a mix of fresh and saltwater, making it even harder to find suitable tank mates.
* They're venomous: The venom of figure 8 puffers can be dangerous to humans and other fish.
While some people have success with certain tank mates, it's generally not recommended.
Here's a very short list of *potential* companions, but remember they come with significant risks:
* Other pufferfish: Some smaller pufferfish, like the dwarf puffer, may be able to coexist with figure 8 puffers in a *large* tank with plenty of hiding places. However, it's still risky, and they must be closely monitored.
* Large, tough fish: Some large, tough fish, like certain species of cichlids, may be able to withstand the aggression of a figure 8 puffer. But again, this is risky and requires a very large tank.
It's best to keep figure 8 puffers alone or with other figure 8 puffers in a species-only tank. This way, you can ensure the safety and well-being of your fish.
Remember: If you're considering tank mates, research thoroughly and consult experienced aquarists. Be prepared to carefully monitor the fish and be ready to separate them if needed.