Lionfish and Scorpionfish belong to the Scorpaenidae family. The genera of available fish include Rhinopias, Scorpaenopsis, Taenianotus, Pterois, and Dendrochirus. These fish are found throughout the world in tropical and temperate waters, and are most commonly associated with coral reefs. These fish are closely related to Sea Robbins and Sculpins. The size of these fish varies, but most members reach an average length of seven inches in an aquarium. The largest member of this family can reach an adult size of over 20 inches in length in the wild.

All members of this family are venomous; they have hollow dorsal (top) spines that are used to deliver toxic venom. The sting from these fish is quite painful, and the reaction to its sting varies among individuals. In the unlikely event that breathing difficulty or vomiting occurs, seek medical help immediately. Lionfish are not usually aggressive toward aquarium owners and most stings result from inattentiveness while cleaning the aquarium.

Lions and Scorpions are hardy fish that adapt well to life in an aquarium. Most of these fish are solitary, but some species are found in small groups. Members of this family eat small fish and crustaceans in the wild. They usually prefer live foods in an aquarium, but some species convert to frozen foods quickly especially when young. Provide these fish with ample hiding places and an appropriately sized aquarium for the species.

No distinguishing characteristics differentiate males from females, and the breeding of these fish in an aquarium is extremely difficult.