A blackback butterflyfish (Chaetodon melannotus) in the Great Barrier Reef. 🐠 Photo by Leonard Low (CC BY 2.0#AquariumKids#Fishkeeping#AquaticAnimal

A green terror (Andinoacara rivulatus) at the Karlsruhe Zoo. 🐠 Photo by H. Zell (CC BY 4.0#AquariumKids#Aquariums#AquaticAnimal

A fire dartfish (Nemateleotris magnifica) in Indonesia. Photo by Rickard Zerpe, licensed under CC BY 2.0: https://creativecommons.org/licenses/by/2.0/deed.en#AquariumKids#Fishkeeping#AquaticAnimal