Domino Damsel (Dascyllus trimaculatus)

Juvenile Domino Damsels will happily shelter inside a host anemone right alongside a clownfish, riding out the same sting-proof mucus trick without any of the partnership baggage — they just move in and mooch the protection. They lose the habit, and most of their patience, as they grow, turning into one of the toughest, most territorial fish a beginner tank will ever hold.

Care level: Easy · Temperament: Aggressive as it matures · Max size: ~5" · Min tank: 30 gal · Diet: Omnivore, marine flake/pellet