I feel like the blue ringed octopus may be harder to keep than the nudibranch because of how octopuses are master escape artist the blue ring is extremely toxic they have beak that may be able to break your finger seeing how that they use there beak to open shells and if it were to bite you may die because i doubt your local hospital will have their anti venom and also im pretty sure they are cites protected so getting one will be near impossible lol i dont even think that there is a private aquarium that have both these species but then again i can be wrong who knows
