This article will, despite its name, not  really be about freshwater sharks such as the bull shark which can frequently  be found in freshwater, but rather be about the different types of minnows that  are commonly referred to as freshwater sharks even though they aren’t even  closely related to the true sharks. 
            The most common types of so called freshwater  sharks are found in the genera Balantiocheilos, Epalzeorhyncho or Labeo, but quite  a few species from other genera are also referred to as sharks from time to  time without actually being true sharks. 
            The genus Balantiocheilos contains one  single type of so called freshwater shark, Balantiocheilos  melanopterus. This species is commonly known as Bala shark and might be the  most common type of freshwater shark of them all. Bala sharks live in Laos, Malaysia,  Thailand and Indonesia and  can grow to a size of 36 cm / 14 in. This type of “freshwater shark” is hardy  and will accept most types of food. They are very adaptive in regards to water  conditions but prefer a pH of 6-8 and a water temperature of 22-28 degrees C / 72-  82 degrees F. This species is often sold to as fry to unsuspecting aquarist who  plan to keep them in their small or medium sized community aquariums, but Bala  sharks should only be bought if you have room for a school of these fishes and  can house them as they reach their full size. An interesting fact about the  Bala shark is that it – just like all other types if so called freshwater sharks – lacks teeth. 
            The genus Balantiocheilos contains five types of freshwater  sharks of whom the most widely known and most popular are the Red tailed shark Epalzeorhynchos  bicolor (earlier considered a member of the genus Labeo) and the Rainbow  shark Epalzeorhynchos frenatum. The species in this group is found in  Far East Asia. The various freshwater sharks in this group can all be cared for  in a similar way. They can all be kept in water with a neutral pH-level and a  water temperature of 24-26 degrees C / 75-79 degrees F. Some species are  hardier and can accept larger differences in regards to pH-value and  temperature. Always research the particular species of freshwater shark you are  looking at before buying it. It is very important to have a well covered  aquarium when dealing with these sharks since they are excellent jumpers.
              
               
 
            Bala Sharks - A type of freshwater sharks. Copyright www.jjphoto.dk
            
              
              The genus Labeo contains a total of 103 described  species of which only one (or perhaps two) species are common in the aquarium  trade and known as a type of freshwater shark. The most common one is the Black  shark (Labeo chrysophekadion). This  beautiful night black “freshwater shark” grows largest of all the different  types of freshwater sharks that are normally kept in aquariums. It can reach a  size of 82 cm / 32 in which in reality only makes it suitable for public  aquariums and (the very small crowd of) hobby aquarists fortunate enough to  have really large aquariums. The Black shark can be very aggressive towards  other fish of its own species and is best kept without other Black sharks  present unless the aquarium is large enough for several territories to be  established. Just like all types of freshwater sharks in the genus Balantiocheilos,  the Black shark prefers an aquarium with a number of suitable hiding places. Black  sharks do best if the temperature is kept at 24-27 degrees C / 75-81 degrees F  and the pH at 6.5-7.5. 
              
               
 
              A Black Shark – labeo Chrysophekadion - A type of freshwater shark. Copyright www.jjphoto.dk
              
              
              
              There are a number of other fish that from  time to time is referred to as freshwater sharks and thereby could be  considered “types of freshwater sharks” but these species are either not very  usual in the trade or is more commonly know under names that don’t falsely  brand them as sharks. You can rest assured that anything you might find in your  local aquarium shop that is labeled freshwater shark isn’t really a freshwater  shark even if there are true sharks that live in freshwater large parts of  their life in the wild. (Some species of true sharks are even suspected to live  out their entire life in freshwater, but this has not yet been confirmed.)