Scorpion-/Lionfish (Scorpaenidae) are both pretty and interesting because of their special appearance and behaviour.
They are generally hardy and do not need a large swimming area, but do often require feeding with small live fish and/or shrimps. Some will quickly begin eating frozen fish or shrimp whilst others will refuse to eat "dead" food. Their food must be highly nutritious and varied. They must not be fed too often. Feed them a large meal twice a week.
These fish are mostly peaceful, but will eat anything that fits into their mouth. One might be surprised by how large their prey can be, they can even swallow fish which nearly match their own length. They will also eat each other, if the size difference is large enough. Their venomous spines do not guarantee that they will not be eaten by other predatory fishes.
Do be cautious when having your hands in the aquarium as these fish are very poisonous.
Some Scorpionfish require a special substrate, either coral gravel or fine sand, as this resembles their natural habitat.
Be careful when catching Scorpion-/Lionfish as they can easily get caught in the net.
This kind of Scorpionfish likes to hide in between the branches of large stony corals, Acropora for example, so make sure to keep them with there corals in the aquarium. They stay hidden a lot of the time, so they are not seen very often.
This type of Scorpionfish is considered by many to be the most exclusive, which is duly reflected in the price. It is very prone to infection, so it is important to be familiar with treatment of various infectious deseases.