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The Redtail shark, also known as the red-tailed black shark, red tail shark minnow, or the firetail shark, is a freshwater fish native to Thailand. The fish occurred in the clear waters and floodplains of the Menam Chao Playa basin but have since been recorded as extinct due to excessive poaching. The fish is found in aquariums in private collections. Redtail sharks belong to the Cyprinidae family, and the scientific name for this fish is Epalzeorhynchos bicolor. Despite the name red tail shark, the fish are actually a type of carp and not a shark.

Astellar87, CC BY-SA 4.0, via Wikimedia Commons

In this article, we will show you the complete guide to care for red tail sharks in captivity.


Common NamesRed-Tailed Labeo, Red-Tailed Black Shark
Scientific NameEplazeorhynchos bicolor
ColorBlack with orange or red Tail
SizeUp to 6 inches
Tank Size55 Gallon
Lifespan5 to 8 years
TemperamentSemi aggressive
Temperature72to 79 degrees F
Freshwater or SaltwaterFreshwater
CompatibilityNot ideal for beginners


Despite all the worrying information you have about the red tail shark, such as aggression towards the mates, it should not scare you away from introducing them to some friends. If you do this in the right way, then they will co-exist peacefully with their tankmates. They get so aggressive when they notice that their place has been invaded or whenever they are feeding. To solve the issue of territorial aggressiveness, it is important to ensure that the tank is spacious enough to the point that none of the fish feels their space is being invaded, and the problem of feeding can be solved by ensuring that you put food throughout the tank and ensure they feed several times a day.

The red tail sharks usually set out to chase the other fish until they give in to stress. This, at times, prevents the other fish from eating, and they even starve to death. While they are not known for playing with other fish, it does not mean they entirely cannot live with other comes, and below are some other compatible species.

The redfish sharks are compatible with fast-moving or schooling fish that live only in the upper or the middle level of the tank. For instance, if you are using a large tank, you can include the Bala shark inside since it is a peaceful fish that prefers living near the surface. The barbs are another species that can be compatible with the red tail sharks since they are fast and they move in groups. Others are;

  • Tinfoil
  • Tiger barb
  • danios,
  • small schools of zebra danios
  • giant danios


The red tail sharks are on their worst behavior when they are around their own kind or the same species. They get very aggressive, and therefore it is important to have a mechanism how to manage them in case they must stay together within the same tank. However, it is the best idea to avoid keeping them together, but f that is not possible, here is what you are supposed to do. If you decide to keep a few together, you should provide a big tank that is at least 100-gallons. Divide the tank into separate sections so each shark can have their own space. That way, you will have solved a lot of confrontations.


Redtail sharks are flashy and eye-catching with their amazing coloration. The fish has a sharp contrast of mostly velvet-black body and a bright red tail. The fish are mostly confused with the rainbow shark because of their similar coloration and shape. To tell them apart, look at the fins; the red tail sharks have black fins, whereas the rainbow shark has red fins and tails. The sudden change in color from the black body to the red Tail is the most striking and appealing thing about red tail fish. The color shifts from black to bright red at the end of the caudal peduncle and remains steady throughout. You can spot a vertical line where the color change happens as it does not change gradually.

Redtail sharks have a body like that of sharks; long and thin bodies. Their shape is that of a torpedo. The dorsal fin begins almost halfway to the back of their body, and the rest of the fins except the caudal fin are much smaller.


Redtail sharks grow to up to 6 inches when in captivity but can even grow to 7 or 8 inches. The fish have an average life span of 5 to 8 years, but they live even longer when they exercise proper care. Proper care includes keeping the fish in great habitat, feeding them properly, and reducing their stress.

Redtail sharks are easy to take care of but require special attention for them to thrive. Proper care will make the animals less aggressive and playful, which is fun to watch.


The Red Tail sharp is a native of Bang Pakong, Chao Phraya, and Mae Klong rivers in Thailand. They prefer living in shallow clear water with a heavy growth of algae. With tike, it has been reported that this species has become extinct in this place. This is mainly due to overfishing, poaching, and other human activities.


The average lifespan of this species is between 8 to 15 years, and this is mainly influenced by the level of care you are taking care of.


The Red Tail Shark is generally an active fish that is interesting to watch. In most cases, you will find them swimming at the bottom of the aquarium as they dart away to investigate other areas that seem to be interesting. It is this high level of activity that makes it necessary to give an adequate tank size. This is because they need enough space and room to roam.

 If they are kept in a congested rom without proper spacing, they are likely to display some aggressive behavior towards other fish. If you keep them in the same tank with the wrong tank mates, they are also likely to be aggressive. They are generally territorial, and they need their own spot in the aquarium to feel comfortable.



Redtail sharks are very active fish and therefore require enough space to swim. The fish are also aggressive in nature, and a large space is essential to limit the interaction with others which might trigger aggressive behaviors. Immature red tail sharks require an aquarium of at least 29 gallons, whereas the adults require at least a 55-gallon tank.

 Split the tank up to regulate the fish territorial behaviors and help in protecting the timider fish in the tank. You can use driftwood or caves to split the tank and make sure the tank is well planted.


The red tail sharks do best in fast-flowing water bodies, and therefore you should simulate the environment they are living in with a powerful filter in the aquarium. A regular suspending filter is ideal and would meet all the necessary requirements, but if you can afford a canister filter, it would be more effective for a large tank like the red tail aquarium. They will try as much as possible to clean the algae in the tank, but they cannot eat it all, and therefore you will need to clean out the leftovers from the tank on a regular basis.


The original natural habitats are full of vegetation, wood, and rocks and so try as much as possible to replicate this environment. This ensures that the fish are comfortable and familiar, thus reducing their aggressiveness. Put medium-sized and durable plants like hornwort and water wisteria in the tank. 

Several red tail sharks have been recorded to prefer water plants compared to caves as their habitat in aquariums. Put in some driftwood to increase the variety and places for the fish to hide. Redtail Sharks are bottom dwellers most of the time, so you should consider adding substrate like medium-sized gravel and pebbles into the tank. Make sure that your tank is large enough such that even after putting all the things inside, there is still enough space for the fish to swim.


The red tail sharks spend most of their time on the tank’s bottom side, and therefore it is crucial to provide some substrate in the aquarium. The perfect material to use for that purpose is the smooth stones mixed with gravel and pebbles.


You should also ensure that the tank is always protected by covering it using a weighty lid. This is because the red tails may jump out, or they may also trigger the other tank mates to jump as they try to escape from them.


Light is essential for the tank, so make sure your tank is not enclosed, and if it is enclosed, cover it with translucent sheets. The light helps in the growth of algae in the tank for the fish to feed on.

Tank cleaning

The process of taking care of the red tail sharks is not as complicated. Firsts, you should ensure that you always clean out their habitat, that is, the tank, once a week, and make sure that you have cleared all the uneaten food in less than 2 hours just to ensure that the environment remains clean and safe. The tank should be cleaned Luke warm water and a piece of cloth. Ensure that there is no soap-based or chemical component is used in cleaning.


These animals are generally resilient and hardy, and therefore they can adapt to a wide range of water requirements, but they do not overstep their boundaries. The PH value can be maintained at the neutral value in the range f 6.0 to 7.5, and the water hardness in the range of soft to medium. The red tail shark is not so much sensitive to the abrupt changes in water parameters, but as a keeper, you should closely monitor it so that some drastic situations do not occur.


Redtail sharks are hardy animals and can tolerate reasonable water parameters. The ideal water temperature should be between 72- and 79-degrees F and with a Ph of between 6.8 to 7.5. The water hardness should be somewhere between 10-15 KH.

Find a solid aquarium testing kit to take the water parameter readings accurately. Always check the water parameter consistently to avoid shifting out of the recommended windows, which might, in turn, negatively affect the health of your red tail sharks.


The water in the tank should be flowing fast to make them feel as if it is their natural environment. You can stimulate the environment in the tank with a powerful filter like the regular suspending filter.


It is advisable to recommend water replacement regularly. If you decide to replace it on a weekly basis, then you should replace 10 percent of your water tank. If you decide to do it after a fortnight, you should replace 20 percent, and if you do it on a monthly basis, then you need to change about 40 percent. You should never replace the entire water since it will kill the useful bacteria, and the new water should have the same parameter as those discussed.


Redtail sharks are omnivorous and primarily feed on plants, worms, crustaceans, and small insects in the wild. The fish are scavengers in that they are not picky and eat almost everything that you feed them. It is quite difficult to provide the fish with food from their natural habitats, so you can try and come close to that kind of diet.

You can feed red tail sharks with flakes or pellets as the primary source of nutrition. Pick the high-quality pellets or flakes for nutrition purposes. Add some other foods to provide variety and enrichment to the diet so that your sharks may become happier and as well extend their life span. Examples of food varieties include bloodworms, brine shrimp, krill, daphnia, and tubifex. These foods are rich in nutrients and protein that play a very big role in the development of your fish. The various foods also bring out different active behaviors in your fish.

Vegetables like zucchini, peas, fruit, or cucumber are recommended by aquarists to increase the variety of food. Clean the vegetables and quickly remove the remainders from the tank to avoid lotting. Ensure the vegetables are cut into small pieces so the fish can have an easy time eating them. Feed the fish more vegetables than meat and ensure that you regularly change their diet.

You can also go a notch higher and make your own fish food that will provide your red tail sharks with the best possible diet. Redtail fish also feed on algae, and occasionally you will notice those scraping algae from stones in the tank. The fish, however, do not feed on many algae as is the case with other fish species and therefore are not ideal cleaning fish.


Redtail sharks should be fed on a daily basis, and you should follow a strict schedule to ensure that the fish are not overfed or underfed. Feeding the fish with a schedule also helps you to develop a routine with the fish in that they will get used to being fed at certain times and also help them to fit into the new habitat. The red tail sharks supplement their diet with algae on the aquarium rocks and with the uneaten food in the tank.

Take care that you do not overfeed the fish because of them not being picky on any food. How do I know that I am overfeeding them? How do I know the fish are full? You might be asking yourself these questions, and the correct answer is that if you do not know that the fish has not eaten whatever you offered them for a couple of minutes, then it means that the fish are full and you are giving them too much food.

Keep an eye on the amount of food being eaten and the amount falling to the substrate. Uneaten food compromises the quality of water, so it is necessary to measure the food given to your red tail sharks to avoid any wastage or the risk of illness brought about by the infected water.


Breeding is a very crucial process, especially for a species of fish that is endangered. Breeding the red tail fish from the aquarium has probably been one of the ways to put them back on the map. This fish is still a mystery since there is not much known about their breeding habits. One of the clear things that are known is that whenever the female is on heat and is ready for breeding, the abdomen starts to enlarge.

However, before then, you should avoid just going and finding her a mate before the right time since they feel intimidated and cannot stand the sight of each other. To save this species from extinction, some commercial facilities have taken it upon themselves to breed this species. Inside these facilities, the hormones are introduced into the habitat, and these triggers mating among them. This is, however, not easy unless you have the means of getting these hormones.

When the female becomes pregnant, it looks for lock and darker areas in order to lay eggs. If it is in the wild such places would be in the caves. The babies of the red tail shark emerge after a period of between 40 to 60 hours, and they come out in silver color. After a period of around four days, you will be able to see these babies swimming freely.

These young ones change their color as they grow, just like salmon species. They usually evolve from silver-to-silver brown, and eventually, they turn to black. The young red Tail usually emerges at ten weeks, and at this age, they need a lot of live food in order to develop well to maturity.


Remember that the tail fins of this fish become a duller red when they are stressed or whenever something is not right. Since they are normally active, you might think that they are stressed, sick, or tired when you realize that they are floating around aimlessly and they are no longer busy as they are used to.

Apart from making sure that they have high energy levels and they have vivid Tails, you also need to monitor the condition the fins are in. Always ensure that they are not shredded, frayed, or have holes in them, as this could be disastrous for their overall health. When you notice that they have started to gull, this could also be an indication that they are ailing.

 The red tail sharks are relatively easy to take care of, and therefore as a beginner, this is an ideal fish you should consider keeping. However, if you are an experienced aquarist but you do not have enough space, you should not have more than one of these species since they need adequate space to thrive. The more you add, the more space you will need.


As said earlier, the red shark is a hardy fish, and therefore they do not fall ill easily. However, under poor conditions, they can break down. The most likely disease of the red tails is that of the freshwater breed. However, most diseases are fatal if treated as soon as the symptoms are seen. Below are some of the tips to prevent your red tail shark from getting sick;

  • Ensure that the process of transporting the fish from the point of purchase to the new home is as stress-free as possible.
  • After you have purchased the red Tail and brought it home, ensure that you quarantine it e whenever you buy the tank mates for them. This gives you the opportunity to observe the new pet properly for a short time and also this time assists the new pet in adapting fully to the new environment.
  • Once you have fully established that your new red tail shark is fine, you can now add it to the community tank.

Some of the diseases you should watch it for are dropsy and ammonia poisoning.


This is popular among the red tail freshwater sharks, and it affects the gills of the fish and makes it difficult for them to breathe.   In some instances, the red Tail that dwells at the bottom of the tank will go to the top in order to catch some fresh air. The rest of the symptoms are more noticeable, and they include reddened inflamed gills.


The main cause of this disease is when an efficient nitrogen cycle is not enabled when the good bacteria are not working actively. In most instances, there is a lot of rotten food in the tank, or the fish are producing a lot of waste.


Ammonia poisoning can be avoided by reducing the number of fish that are kept in one aquarium because overcrowded tanks result in more waste, and this increases the chances of getting contamination.

Perform regular water changes in your aquarium to reduce ammonia.

The water in the aquarium should be changed into bits, for instance, 20 percent weekly or 50 percent weekly, depending on the number of fish that are in the tank. This prevents you from disrupting the amount of nitrogen cycle that is constantly taking place inside the water.


This is a freshwater disease that is also known as the Malawi boat. The red tail shark gets it as a result of dirty water in their tank.


The red tail shark has a bloated stomach that is noticeable

The red Tail seems very weak unless their a normal busy self. It would not swim around the tank a lot.


It is important to always change about 25 percent of water in the aquarium frequently.

Use proper medication whenever you are treating this disease

Feed the red tail fish with highly nutritious food, and this will build up a strong immune system and will make it less susceptible to diseases.


A red-tail shark is a fun but challenging fish to keep. While, in most cases, they do not get along well with other fish, you can still keep them together with other fish if you are careful. Just a reminder that despite the fact that this is a mall fish, you will need a large tank and put in some extra effort.

Although they can be aggressive, a lot of people over exaggerate their personality, and this leads to an undeserved bad reputation. Even though they can be a handful, they are not too difficult to handle. When they are kept in their own tank, it is fun to watch as they prey, just like the miniature shark. They are colorful enough to draw attention to even a single species set up too.


Are Redtail Shark Freshwater fish?

Yes, the Red Tail Shark is a freshwater fish that originates from the Chao Phraya and Bang Patong Rivers in the Gulf of Thailand. This species loves living in shallow ponds with clean flowing water that has plenty of rocks and sandy substrate.

Can Red Tail Shark Bite?

The Red Tail Sharks are semi-aggressive, and they will rarely bite even if they get aggressive. They do not do any kind of damage to the other fish.


The red tail shark is a freshwater shark that no doubt will continue to be popular in the aquarium scene for quite a while. These fish are dealt with for a different range of experience levels due to their unique look and straightforward care requirement. The only challenging bit is dealing with its aggressiveness towards others.

However, by preparing this guide, we hope that you have got an insight into what you need and that the red tail shark needs, and you have been encouraged to give this amazing species a shot.

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