Rainbow Shark - Epalzeorhynchos frenatus

The Rainbow Shark (Epalzeorhynchos frenatus) has a dark grey body with red fins, a short black line throughthe eyes and a black spot at the base of the tail. An albino variant is also common which has a pinkish-white body, red eyes and red fins. This shark is very similar to the also-common Redtail Shark (E. bicolor). The Rainbow Shark has a grey body and all fins are red while the Redtail Shark has a grey body and fins and only the tail is red. Mixing these two species or keeping more than one of either species is not recommended as they can become very territorial, especially in smaller aquariums.

Some of the most popular fish for the freshwater semi-aggressive community are the cyprinids known as sharks. These are not the cartilaginous carnivores you see in movies or on the Discovery Channel. These fish are found primarily in the waters of Southeast Asia and Thailand. There are several species that are often imported for use in the aquarium trade, and several species also referred to as sharks that are less common in the trade. Though from several different genera, these fish all have in common the pointed heads and large, curved dorsal fins that give them their misleading common names and are more closely related to carp, loaches or barbs than saltwater sharks.

Sharks make bold and interesting additions to freshwater semi-aggressive communities, as long as the tank is of adequate size and the conditions in the tank suit their needs. Though these fish lack teeth, some species can grow quite large and territoriality can make them troublesome as they mature. They are generally not suitable for tanks under 55 gallons (some not less than a 75 to 100 gallon tank). Sharks should only be housed with fish that can stand up to chasing and harassment from sharks, especially towards their own kind. Smaller fish may eventually be seen as food items as the fish grow. Suitable tank mates for most include fish like barbs, catfish, large tetras, and other fish of similar temperament.

If you are considering the addition of a shark to your community, there are several things to keep in mind. As far as the set-up goes (besides having an adequately sized aquarium) be sure that you provide plenty of cover like wood, plants or rock formations so these fish can hide and feel secure when they feel the need. A tightly fitting lid is also highly recommended as they tend to be terrific jumpers, especially if startled. Most common sharks prefer well-aerated, clean water with temps between 74 and 81 degrees (F) and a pH maintained between 6.5 and 7.5. Sharks do not tend to be finicky eaters, readily accepting flakes, pellets and frozen, freeze-dried or live treats like bloodworms, tubiflex, glass worms, plankton, brine shrimp or other meaty tidbits.