Red Tail Shark: Care, Tank Size, Breeding, And Tank Mates

Yes, it is still safe to go back into the water! This fish isn’t a great white! It’s not even one of those great black sharks that I have told you about! This fish doesn’t have a mouth full of teeth, but it can still be a tiny terror in your tank! It’s one of the most popular and attractive freshwater sharks available in the hobby: the Red Tail Shark!

One of the first sharks I ever acquired for my home aquariums was the red tail shark. The first sharks I had purchased were red finned cigar sharks. Needless to say, the red tail shark was a much different shark, not only in appearance but also in behavior!


It’s easy to see where the red tail shark gets its name. While the body of this fish is black, the tail of this shark is a striking, bright red. In some cases, the red tail shark’s black dorsal and pectoral fins may even be tipped with white. Usually, these white tips will fade as the fish matures, as most of these white-tipped red tail sharks are juveniles.

Some red tail sharks may also be found without a red tail! I have seen and purchased red tail sharks with white or tan-colored tails. At first, I thought these sharks were a new strain of red tail shark, but I have since found out the truth. These red tail sharks without the red tails are usually sick or stressed out, and their tails have simply lost their color! In some cases, even some older specimens’ tails may fade in color.

The red tail shark is very often confused with another similar looking shark, the rainbow shark. The easiest way to distinguish between the two sharks is to look at their fins. The red tail shark will have a red tail and black fins, while the rainbow shark will have a red tail and a red dorsal fin. Even the albino rainbow shark is often confused with the red tail shark. Usually, the rainbow shark is more “streamlined” and slender than the red tail shark. Another big difference between the two sharks is the level of aggression shown by each species. While the red tail shark can be a terror, the rainbow shark is definitely the most aggressive of the two.

Another shark that is closely related to the red tail shark is the black shark. When the two sharks are juveniles, they are nearly identical, aside from the red tail. However, the black shark will soon outgrow the red tail shark by leaps and bounds! While the black shark can grow as large as two feet in length, the red tail shark rarely grows any larger than 5 inches in length.

The red tail shark is obviously not a true shark. Like the rainbow and black sharks, the red tail shark gets the shark moniker from its shark-like dorsal fin. In reality, the red tail shark is a member of the cyprinid family. This is the same family that includes goldfish and carp. (The red tail shark doesn’t sound so fearsome now, huh?!)


The red tail shark is a native of Thailand, although most of these fish are now raised on fish farms. It is actually believed that the red tail shark is extinct in the wild due to the fish’s popularity in the pet stores! In the red tail shark’s natural habitat the fish swims in fast-flowing streams, canals and in overgrown waterways with rocky bottoms and strong currents. When setting up a home aquarium to house red tail sharks, these conditions should be taken into consideration.

Food & Diet

Feeding the omnivorous red tail shark should prove to be quite easy. The red tail shark has a down turned mouth like those of loaches and many catfish. Because of this, the red tail shark prefers sinking foods like sinking wafers or shrimp pellets. However, the red tail shark is not a picky eater. The red tail shark will also readily accept flake foods, live or frozen bloodworms, glassworms, earthworms, fruit flies and brine shrimp. Just keep in mind that some type of vegetable matter will need to be included in the red tail shark’s diet. Without any type of vegetable matter, juvenile red tail sharks are often poorly colored or stunted in growth. Much of the red tail shark’s vegetable needs can be found through algae, which the fish will gladly clean from the tank’s decorations.

Tank Size

Due to the red tail shark’s smaller size, the fish will need at least a 20-gallon tank. An ideal permanent home for a group of red tail sharks would be a 55-gallon aquarium. The aquarium should have some dense vegetation and contain some cave-like structures, pieces of pipe or bogwood for the shark to use as its own territory. The more territories that are made available to the red tail shark the better. This will cut down on any aggression between other red tail sharks or other fish. The red tail shark will aggressively protect its territories from other red tail sharks and even other fish, including fish that are much larger than the red tail shark! It is even believed that territories should be placed far enough apart so the red tail shark won’t see other red tail sharks, because the red tail shark will often act aggressively toward another red tail shark simply on sight alone!

Due to the red tail shark’s aggression, you have two choices when deciding how many to place in one aquarium. You can either choose to keep just one red tail shark or go the other way and keep more than six red tail sharks! Just don’t keep a few red tail sharks since if there are less than six of these fish in one tank, they will begin to quarrel with each other and the weakest of the red tail sharks will be miserable. This misery will lead to the red tail shark becoming stressed, which will then lead to sickness and eventually death.

Tank Mates

The red tail shark will be compatible with such fish as gouramis, barbs, danios, rainbows, bala-sharks, iridescent sharks, red finned cigar sharks, pictus catfish, swordtails, silver dollars, angels, most loaches and even some types of cichlids. The red tail shark will not harass any of these fish, but they will defend their territory from any intruding fish, usually just chasing the trespassing fish away. It is even believed that the red tail shark will act aggressively to other fish if they have red fins, apparently believing the fish to be another type of red tail shark! Because of the red tail shark’s aggression, many hobbyists choose to keep this fish with larger, equally aggressive fish, including cichlids, or in a red tail shark only aquarium.

While the red tail shark is considered to be relatively hardy and may live for several years, this fish is sensitive to water conditions. The water in the red tail shark’s aquarium will need a pH between 6.5 and 7.5 with a temperature between 72 to 80 degrees. The water quality should be kept high through very good biological filtration because the red tail shark is highly sensitive to nitrites.


The red tail shark is not known as a good breeding fish for the home aquarium, but it is remotely possible to breed the sharks. It may be a little difficult to distinguish between the male and female red tail sharks. The females are often slightly bigger and in some cases plumper. The easiest way to tell the difference between the two sexes is by looking at the red tail shark’s dorsal fin. The males usually have a more pointed dorsal fin, while on the females the rear edge forms a right angle.

Breeding in the home aquarium is difficult due to the red tail shark’s aggression and occasional intolerance toward other red tail sharks. Most red tail sharks are bred successfully in large, heavily planted, outdoor ponds. However, it is not unheard of for the red tail sharks to occasionally breed in the home aquarium. If they do decide to breed, the red tail sharks will be seen making odd swimming motions around each other. The male red tail shark will often be seen darting about. After the two red tail sharks successfully mate, 30 or 40 eggs will then be laid in and among the aquarium’s plants or in some rocky crevice or crack. After the eggs are deposited, the male shark will then guard the eggs. In most cases, the red tail shark eggs will hatch 2 to 3 days later. The fry will be able to swim freely by the time they are two days old. Once the fry reaches a ½ inch in length, the young red-tail sharks will then begin to acquire their adult coloration. This coloration should fully develop by the time the red tail sharks are 8 weeks old.

Due to this fish’s great popularity, the red tail shark is imported frequently and is easily found in nearly every pet store and even in most wall-to-wall discount marts. However, you may find the red tail shark under a number of different aliases: the red-tailed shark, the red-tailed black shark, the red-tailed black labeo, and one of my favorite names, the firetail shark. In most instances, the red tail shark will be found at a very affordable price. I have seen this fish available anywhere from $3.00 all the way up to $8.00, pocket change if you decide to keep just one of these beautiful, energetic fish in your home aquarium, and still affordable enough if you want to go the other way and buy more than 6 red tail sharks at one time!


  • Vidthayanon, C. 2011. Epalzeorhynchos bicolor. The IUCN Red List of Threatened Species 2011

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