Genus
Common name: Blue-ringed octopus
Scientific name: Hapalochlaena
The genus Hapalochlaena is known for the striking blue rings that appear as a warning when the animal is threatened. These small octopuses are famous for their potent venom, containing tetrodotoxin, which can be fatal to humans. Despite their danger, they are sometimes kept by experienced aquarists in species-specific tanks. They require a secure tank with no tankmates, as they can escape through tiny gaps and may pose a risk to other inhabitants. Their diet consists mainly of small crustaceans. Due to their specialized care requirements and potential danger, they are not recommended for most hobbyists.