Red Tailed Shark

The red tail shark is a member of the Cyprinidae family of freshwater tropical fish. The red tailed black shark falls into the same family as carp and minnows. Contrary to the name, the red tailed shark is actually not a shark. The “shark” name came from the dorsal fin this freshwater tropical fish possesses resembling an actual shark.

Common Name/Origin: The red tail shark is also known as labeo bicolor, fire tail, red tailed black shark, and epalzeorhynchus bicolor. This Cyprinidae originates from the streams and waterways of Thailand.

Size: The red tailed shark averages 6 inches in length.

Temperament: The red tailed black shark can be an aggressive fish. This fish often fights or harasses other red tail sharks. It is highly recommened to house only one of this species unless you have a very large tank. The red-tailed-shark should not be kept with extremely docile or peaceful fish. The red tail shark is a territorial fish that will chase other fish away from their territory or become aggressive during feeding. Some fish-keepers have had great luck with their red tail shark, so it all depends on the individual fish.

Sexing: This species is extremely hard to sex. Female epalzeorhynchus bicolor sharks are usually larger than the males. The female will have a full, wide stomach and the males will be more slender.

Tank: The aquarium tank recommended to keep the red-tail shark is at least 20-gallons. The tanks should be decorated with several places for this fish to hide. The red tail shark will enjoy a well planted tank with caves or driftwood for shelter. The tank should have a tight fitting lid because this freshwater tropical fish species is known to jump out of tanks.


pH: 6.5-7.6

Soft-Medium Water

Temperature 72-80 °F

Feeding: The red tailed black shark is an omnivore scavenger. This freshwater tropical fish will eat just about anything that you put into the tank. Like any other fish I keep, I recommend a very high quality pellet or flake food and supplement with brine shrimp, mysis shrimp, small krill, or bloodworms. Like any other freshwater tropical fish, please mix up their diet on a regular basis.

Behavior: As mentioned above, the red tailed black shark can be territorial and chase other fish around the tank. This species of freshwater tropical fish swim back and forth, mainly on the bottom of the tank searching for food. When you feed the tank, you will notice the redtail shark chasing other fish away from the food.

Tankmates: It is highly recommended to keep only one labeo bicolor per tank. Depending on each individual fish, most redtail sharks will harass smaller, more peaceful fish. Many cichlid keepers keep redtail sharks in their tank because they can hold their own with some more aggressive fish. Do not keep red tail black sharks with other bottom dwelling fish such as cory cats. They will compete for the same territory and food.

Key Features: The redtail shark will cruise near the bottom to mid-level of the aquarium tank. This fish is an active fish and is constantly on the move searching for food. The unique look and shape of this fish is what many fish-keepers love. The shark-like dorsal fin and beautiful red tail contrasted with the black body makes this fish very appealing.

Breeding: The red-tailed shark is extremely hard to breed in the home tropical fish aquarium. Most specimens purchased in our local fish stores are bred in commerical fish farms in Thailand. The red-tail shark is an egg layer.

Summary: If this popular freshwater tropical fish is on your list of fish to purchase, please just purchase one of this species unless you have a huge tank. This Cyprinidae is known to be a chaser and will harass other tropical fish in your tank. This specimen often does well with more aggressive fish such as cichlids. Remember to keep a tight lid on your aquarium tank because the epalzeorhynchus bicolor is a jumper!

104 thoughts on “Red Tailed Shark”

  1. I am trying to ascertain who the culprit is in my tank, I have a rts, a banded leporinus, a yo yo, a Julie, 2 krebensis 4 glass cat fish and one remaining angel fish, everytime I get tetra, guppies, mollies or similar they vanish one by one, stomach’s eaten out and even now one of my angel fish had its eye pulled out! Every fish is getting picked off even glass cats, I see the rts acting territorial it’s a 4ft x 2ft tank, but not sure its him that’s doing it, don’t want to re-home unnecessarily, never see the banded leporinus acting aggressively, he is really chilled even though he is 8inches now, the rts is about 5inches, struggling to maintain stock and don’t want to lose anymore fish .

  2. Thanks this was a great help i split my feeding time and the tank has settled a little

  3. I have 1 redtail shark. (Preditor and also they are related to catfish. 5 angel fish( preditor. 4 Cory’s. 5 Guppies. 2 pearl gouramis. 2 dwarf gouramis. 2 gold gouramis. 2 blue gouramis. 4pink widow tetra. 4clown loaches. All fish are friendly with each other
    and At present living in a 3ft tank soon to get a bigger tank before they get any bigger.
    (Note they are are all still young (5 months. But 3 angle fish are about 1 year old

  4. My red tail shark is around 9 years old now a perfect specimen with perfect colouring a fins how many more years do you think it will survive for? Anyone have one thats older?

  5. I have a black shark with red tail and he cheated death 4 times and still survived. He is a real survived. Three months ago I had him in my 19 litre aquarium with other fish and he ripped the tail of the fish off as i did not do my home work on my black shark. I bought a 125 litre -33 gallon aquarium and removed all the other tropical fish and left the black red tail shark in the 19 litre aquarium on his own and he absolutely loves it . Yes it’s true they are fiercely territorial ‘ black shark would block other fish from moving in the tank which can be stressful for the fish. My black shark with red tail jumped out of the tank as I was cleaning the tank, I had my back to the tank and I was at the kitchen sink as I heard a thug noise and I went to the tank and saw the fish had disappeared. I looked on the work top, amount the books , almost everywhere until i was near giving up on looking for him then I realised it was almost five minutes gone and he must be dead by now wherever he jumped and landed.
    I then saw it on the floor in the corner almost hidden and looked like it was taking it’s last breath with its colour gone from jet black to beige and the bright red tail was extremely pale. I quickly shovels him and put him in the tank and he started swimming around and within 15 minutes his natural returned to black and tail bright red. Another time he cheated death, I took him out and tank when he was chasing other fish around the tank’ and put him in a bowl of water and i went to bed that night and in the Morning I woke up and found him on the floor dying and stripped of his colour. I quickly got him back into the bowl and into his aquarium . I actually wanted to teach him a good lesson for ripping the tail off on of the fish when they were all together in the same tank’ before they were transferred into another tank. Since then i did my research and I felt guilty for treating my black shark with badly and realised it’s their nature to chase other fish around the tank as they are territorial and can cause stress to other fish. Black shark is now happy.and peaceful by himself. I NOW HAVE IN MY 125 LITRE TANK”
    1 PLECO

    They all live together peacefully in my 125 litre tank. No fighting and non have died because I have become experience with knowing how to look after them.
    No algae
    No nitrate
    No nitrate
    No probllem with PH balance
    The water is crystal clear and my fish all love the tank and the care they get.


  6. I have a Red Tail Shark that has more than doubled in size since I’ve had him and I was unaware of this Aggressive Behavior until now when I have been reading up on it’s Behavior trying to figure out why it’s chasing half of it’s Tank Mates around causing other Fish to stress. I have a wide variety of Tropical Freshwater Fish in the 40 Gallon Tank including 2 other types of Sharks that are Silver and dark Silver in color and a Cat Fish that is Silver as well. The Red Tail will sometimes wonder outside of it’s usual space in to other Fishes territory and chase other Fish around the whole tank from one end to the other end. I have Live Plants and Ornaments for hiding spots but it’s like he just doesn’t even want other Fish in the same tank as him. I don’t like it when he bullies the other Fish that are just minding their own business and I don’t know how to prevent him from doing it. He’s especially bad when it’s feeding time. What does he expect none of the other Fish to eat ? But there are also certain Fish in the Tank that he doesn’t bother at all. It’s weird. Like he picked out which Fish he is cool with and which Fish he Hates.Had I known his Behavior was gonna be like this I probably never would have Purchased him cause it’s not fair to all the other fish but I have had him for a while now and wouldn’t be able to return him to Walmart where I bought him at this point. Is there any way to calm him down and make him less Aggressive towards his Tank Mates ? He already has a hollowed out log that he goes in from time to time but he still spends a lot of time swimming around that ground and ornaments sucking up whatever it is that he can ingest and if he comes across another fish while doing so it’s automatic chase them away. I don’t know what to do.

  7. Just got a fluval edge 46l can anyone advise of types and number of fish suitable for the tank?

  8. What I like to know what gets on with one of them or should I say what can I mix with one of them.I have one only one many thanks

    1. Mostly bigger fish are fine with them or large shoals seem to be ok just avoid fish with fancy fins and bright colours such as guppies or feather fin plecs, swordtails etc

  9. I have a red tail shark& he is about 8 months old. Suddenly, over the past couple of days, his body has turned white. All his fins are black, except his tail, which has remained red. What’s up with that?

    1. Sounds like he’s stressed losing colour is usually a symptom of an unhappy fish. Have you made any major changes to the tank recently or introduce any new fish even just given it a good clean out and rearrange can upset them.

  10. I have a red tailed shark in a ten gallon tank. I added five penguin tetras and a rummy nosed tetra to the tank yesterday and woke up to only 5 of the 6 tetras, but there was no carcass in the tank. I used to keep my shark in a two gallon with three other tetras and he had no problem with them. I know that a 2 gallon is a terrible tank for a red tail but he was a gift, along with another fish who died in two weeks. I am considering getting rid of my red tail because I want a planted tetra tank. Should I?

    1. Also, is there any way that I could sperate the fish. My red tail is nocturnal and only has problems with the fish at night. He doesn’t like when there is light ne’er the tank and wil hide if I walk by. Could I use a light to keep him away from the other fish, or do I have to accept their deaths?

      1. Probably better getting g rid of him to be honest it’s not a good idea to annoy him with the light. You won’t have found the body previously as the red tail probably ate all the meat and a tetra skeleton is so small it’s hard to see.

  11. Got a Redtail owned for 20 years, he is a hardy fish and learnt his behavior. My tank evolves around him from water imbalance to unwanted tank mate. I’ve got pair of Angels, a Brittlenose & Platys that found works for him. My Sharky had a Clown loach best friend few years ago but past away bought him another it didn’t last long.
    Every tank is different and got find Redtail’s groove with other fish.

    1. quite possibly i have a yoyo loach that follows one of the big commons around I think some fish just seem to pair up don’t really know if there’s any benefit to each other from it they just do perhaps they really want a friend.

  12. I have a 105 liter filed with water and decorations no fish yet should I add a red tail first or my frendily fish e.g moly guppys plattys ext I don’t know cause my other tank has a betta wich I’m not going to ado in with a red tail

    1. Add the community fish first let them establish themselves then add the retail if you add red first he’ll take over the entire tank and adding anything else will end badly

  13. I own two Red tailed sharks and they are the best fish I have ever owned! They keep all the fish in your tank moving and will please any viewer.

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