If you want to keep a predatory catfish, it is important that you find out how large it can grow before you purchase it. A lot of the predatory catfish species are sold as immature and will sooner or later outgrow you aquarium. If you want to keep a comparatively small predatory catfish, the Tiger Shovelnose Catfish (Platystoma fasciatum) is one suggestion. The Tiger Shovelnose Catfish will “only” reach a maximum size of 100 centimetres / 40 inches in the wild. When kept in aquariums, the Tiger Shovelnose Catfish seldom grow larger than 60 centimetres / 24 inches. As long as your Tiger Shovelnose Catfish is smaller than 15 centimetres / 6 inches you can house it in a 122 centimetres / 48 inches tank that fits at least 209 litres / 55 gallons. As your Tiger Shovelnose Catfish grow you will however be required to get it a larger aquarium. A fully grown Tiger Shovelnose Catfish will need a 180 gallon aquarium. It is important that you provide your Tiger Shovelnose Catfish with plenty of open space in the aquarium to swim around in.
Some fish stores will offer their customers a type of catfish marketed as hybrid Tiger Shovelnose Catfish. As of 2005, there exists no known Tiger Shovelnose Catfish hybrids and the fish that is marketed as a Tiger Shovelnose Catfish hybrid is actually a Hemisorubim platyrhynchus.
Ashara Catfish, Perrunichthys perruno, is another example of comparatively small predatory catfish species. I will usually grow no larger than 60 centimetres / 24 inches in an aquarium. You can house this catfish in a 378 litres / 100 gallon aquarium that measures 183 centimetres / 72 inches. Just like the other predatory catfish species, the Ashara Catfish will appreciate large open areas in the aquarium where it can swim around. The aquarium should however never be completely barren; decorate it with rocks and create caves and sheltering places. It is important that the caves are stable enough to withstand accidental knocks from the Ashara Catfish.
Another predatory catfish species that is sometimes kept by aquarists is the Red-tailed Catfish, Phractocephalus hemioliopterus. This grows even larger than the Tiger Shovelnose Catfish and can reach a maximum size of 120 centimetres / 48 inches. If you want to be able to house your Red-tailed Catfish when it becomes an adult, you will need an aquarium that is at least 8' x 3' x 3'.
As the name suggests, all predatory catfish species are skilled predators and they will appreciate live foods in the aquarium. It is however possible to train several predatory catfish species onto pellets. It is important that you choose a high quality pellet that is suitable for large predatory fish species.
It is not uncommon for predatory catfish to panic and thrust themselves into aquarium equipment or into the sides of the aquarium. Since they are very strong fishes, they are capable of severally hurting themselves. Injured snouts are therefore a common problem among predatory catfish species. Predatory catfish can also be a bit jittery, especially when you have moved them from a small aquarium to a larger one.