Red Tail Shark - Epalzeorhynchus bicolor

Updated May 13, 2020
Author: Mike - FishLore Admin
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The Red Tail Shark (Epalzeorhynchus bicolor) has a black body with a red tail and sort of resembles a shark (hence the name).

Unless your aquarium is quite large, it is best to keep only one of them in your tank because they will become very aggressive and territorial towards each other when kept in multiples. Avoid the temptation to keep them with a Rainbow Shark or other Red Tailed Sharks.

Many hobbyists mistakenly add multiples to a small tank only to find out that one of them will soon become the dominant "shark". The dominant one will chase and pester the others relentlessly. Any time the submissive sharks try to get to food the dominant one will chase it away. They really can become quite obnoxious which is why we recommend keeping only one unless you have a much larger tank.

Provide them with many hiding places to help make them feel secure and have a tight fitting hood because they are also known to be excellent jumpers.

They love to scavenge all over the tank looking for food and will accept most fish foods including flakes, frozen, freeze dried and live foods.

Epalzeorhynchus bicolor Two Redtail Sharks Redtail Shark near gravel bottom Epalzeorhynchus bicolor

Red Tail Shark Care Info

Scientific Name : Epalzeorhynchus bicolor

Common Names : Red Tailed Shark, Red Tail Black Shark, Red Tailed Labeo, Fire Tail, Labeo bicolor

Care Level : Easy, good for freshwater beginners

Size : Up to 6 inches (15 cm)

pH : 6.5 - 7.5

Temperature : 73°F - 79°F (23°C - 26°C)

Water Hardness : 10° to 16° dH,

Lifespan : 5 - 8 years

Origin / Habitat : Thailand

Temperament / Behavior : These fish can be hostile and are not recommended for community fish tanks with smaller tropical fish. They seem to behave when kept with larger fish. The skin on this species has been studied and the linked doc shows how different species have different cells and functions. It is a very interesting study.

Breeding : Very difficult to breed in the home fish tank.

Aquarium Size : 55 gallon

Tank Mates : Larger tropical fish given their aggressive nature but none large enough to eat them. It is not recommended to keep them with the Rainbow Shark unless your tank is sufficiently larger.

Fish Disease : Freshwater Fish Disease - Diagnose, Symptoms and Treatment

Food : Omnivore and primarily a scavenger. They will go after most of what you put in the tank including flakes, live and freeze dried foods.

Tank Region : Middle and bottom

Gender : Hard to determine, but the female may have a grayer stomach whereas the males are solid black.

Fish Forum : Red Tail Shark Forum

Photo Credit : Photos copyright

References :

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Red Tail Shark

Red Tail Shark Comments

From: Roger
I made the mistake of getting two redtail sharks. The dominant one just chased the weaker one around the tank until it eventually died. Live and learn.

From: Jared
OK, I did the dumb thing and bought 2 red tails. Is there anyway to prevent them from fighting with each other? Also, what are some other good fish to put with them?
FishLore: Unless you have a very large tank, at this point about the best you can do (short of taking it back to the store) is to provide them with many hiding places. If one chases the other around most of the time, you will have to separate them. They can get along well with a few larger species. Some good tank mates include Silver Dollars, Angelfish, Bala Sharks, Plecos, Cory Cats, Swordtails and more.

From: Adz
I had one of these, it lasted not even a day because as it says above they are excellent jumpers. I put the bag in the tank and had opend the bag to add the tank water to it. I looked back half an hour later and the bag was empty and he wasn't in the tank but on the floor, there was this red tail flipping about. I put it straight in the tank but it died pretty much straight away.

From: Bee
I had a Redtail a few years back that would chase any fish that came to close to its own personal cave. It would chase them away then hide in its cave again. It was quite entertaining.

From: Ike
I had a redtail with a rainbow and they follow each other around and didn't seem to bother each other. Keep them in a big tank because I moved the rainbow down to my ten gallon because my cichlids were eating its fins and he seemed to like it, but in the morning he was nowhere to be found. Eventually I found him dried to the floor.

From: Gunter
I have 2 redtail sharks in a communal tank. Another 10 or so fish in a 2 foot tank, and they seem to get on quite well, I'm positive one is a male and the other is a female.

From: Josh
I've had a redtail for six years, this particular shark has survived in tanks with african cichlids and even given them hell as far as tormenting goes. Currently i have him/her in a four footer with a full grown gold gourami. Sounds silly I know but the gourami actually follows it around as if he appreciates the occasional chase, seems to be some strange sort of friendship. All they ask for is a place to call home with no intruders.

From: Jenn
I have a red tail in a 10 gallon tank with 2 tiger barbs and one tin foil barb. The red tail relentlessly chases and agitates the other 3 fish. It IS quite entertaining to watch but I worry that he/she will injure them or kill them. Should I get another shark to divert his attention or would that be bad?
FishLore: Tiger Barbs are fairly tough fish and so is the tin foil barb. Watch them closely and if it looks like they're not going to get along better you may want to remove it. The tin foil barb can grow to be 10 inches (25 cm) or larger and your 10 gallon is way too small for it. You'll have to return it or get a much bigger tank (55 gallons at least) to support a tin foil barb.

From: Steve
I have a red tail and 6 clown loaches in a 4 ft tank and he gets on so well with them that he even stays in the same cave when they are resting.

From: Bev
They are strong jumpers for sure. After reading here about the reason my 2 two year old red tails stayed hidden all the time in my 55 gallon tank, I moved the smaller one to a ten gallon tank with plastic net taped over the filer & heater holes on the lid. The third day I came home to find him on the floor dead. So when they say tight fitting lid they mean it.

From: Wayne
I have a red tail in with a variety of fish, it pesters my silver shark a little bit. I recently added 2 dwarf gouramis and the red tail has become like a tank buddy to one of them, they follow each other around and it doesn't pester the silver shark as much now. Very amusing.

From: Bob B.
Mine is at the end of his lifespan, hanging listless in the tank with most of his bulk lost. He is at least 10 years old (I have had him for 8 and another had him for two years before that). 55 Gallon suited him fine. Great fish, feisty, ran my big cichlids around whenever he felt like it and know that he killed at least one by ramming it back in the day. Will get another - great fish!

From: Robert
I agree with Steve that RTB sharks seem to love clown loaches, particularly if they are roughly the same size. I have 1 7.5" RTB in the same tank as a 6.5" clown loach, and they seem inseperable.

From: Connor
I have a Red tailed shark in a 50 gallon community tank with a bred pair of kribensis. They both seem to have their own side of the tank. If one goes on the others side they chase the other off. But I don't know if I should move one of them to give the other more room, but it seems that if they are on their own sides they both seem fine.

From: Brian
My red tail shark is usually pretty docile with the other fish in the tank (5 tiger / 2 green barbs, and 3 Odessa barbs.) But come feeding time he is going nuts chasing all the other fish, no matter what part of the tank they are in. Luckily the barbs are a pretty hardy fish, but I don't want them too stressed because it's a new tank and is currently cycling. I like her/him (I think it's female because of a light grey underbelly) but I certainly hope it calms down soon.

From: Bulldog
I have 2 cichlids bigger than my redtail shark who has his own cave. My cichlids get scared when they go pass his cave because he is not peaceful.

From: William
Red tail black sharks will help you curb your freshwater snail population if you don't over feed them. I keep one in a 45 gallon community tank of mollies, gold tetras, dwarf rasboras, and black phantom tetras. I know it's an odd combination but the red tail black shark is now 4 years old and cruises the tank with authority. The snail population has been stablized and shark happily dines on shrimp pellets every morning.

From: Phil T.
My RTBS has been a great addition to my community tank. With 6 active tiger barbs plaus a shoal of neon tetras I was anxious about how its addition would impact upon the community. I had read all the warnings! My anxieties were heightened when I watched around 25 RTBS's engage in open warfare in the shop's tank! Choosing one was a tricky balancing act. I wanted to get one that had not had its dorsal fin ripped to shreds (like some in the tank) but I did not want one so dominant he would terrorise the tank.

In the end I need not have worried. The first five minutes after his release were anxious. The alpha male of the barbs went for him and damaged the very tip of his dorsal fin. The other barbs followed suit and it was chaos for about five minutes. Then the red tail retreated to the shelter of a plant which he has made his home since.

This juvenile red tail has grown in confidence and when the tank is more dimly lit he happily swims around never troubling others and being left in peace by the barbs. Getting feeding right is important. I tend to let the greedy barbs get distracted by flake food on the surface then quickly flick a sprinkle of sinking pellets over the area of his plant. When they sink down he loves to roll on his side and eat off the plant. He also has helped get rid of an algae problem, feeding off a bit of artificial coral after lights out.

I have no hesitation in recommending this beautiful fish but choose carefully at the shop and make sure they bag the one you want!

From: Al
I would suggest keeping a red-tailed shark either by himself or with more than just 1 other fish. I found that he bullied the barb I had put in with him until he died. They definitely like to have their home and they won't let anyone else near it. They are beautiful though!

From: Blue
I have a 5 year old Red Tail. He grew up in a 30 gallon with an Oscar and a Pearl Gourami. They got along fine. The Oscar has doubled both of them in size but no problems. I moved the three of them to a 75 gallon tank and added a 10 year old pleco. They are all living together in harmony.

From: Justin
One morning I woke up and found my red tailed shark in the filter. I just put him back in the aquarium, I had to put something to keep him from going there, they are very good jumpers.

From: Kyle
My red tail shark is mixed with a rainbow shark. They didnt get a long at first but then I put more driftwood and plants in there. They now can hide from each other, although the red tail is the dominate one. They also surprisingly get along with my serpae tetras. Strength in numbers maybe, at 12. I have a very active tank.

From: Anthony
I bought 3 red tail sharks just recently and are in my 55 gallon tank. They are sharing the tank with 3 tiger barbs, 2 goldfish, 3 Giant Danios, and a pleco. At first they were a little wild but have now settled down and just explore the tank.

From: Eric
I bought 2 red tails today put them in a 46 gallon tank with 6 tiger barbs and 3 silver dollars and 2 bala sharks. All fish are small. The two red tails got acclimated after a few hours then one started abusing the other one. I'm just going to keep them in there. I'm not going to return a 2 dollar fish. I'll add another rock for them to hide in.

From: Grant
I was given a rainbow shark by a friend and I already had a red tail shark. The red tail shark chased the rainbow shark for a while, but now they are fine together.

From: Brian
I recently got a red tail shark and have him in a 35 gallon community tank. Sounds pretty dumb I know, but its not bad at all. He is in with some danios, a swordtail, balloon molly, and 2 angels. He just hangs out in the cave and seems to go over everything as if he's cleaning it. It's quite fascinating. He does chase the angelfish occasionally but he only playfully chases for a little while then settles down. All the fish still seem to be doing real well with his addition and I will be adding more fish soon. The red tail is definitely one of the more docile sharks and I haven't seen that much aggression out of him. I recommend getting one, they're a joy to watch!

From: David
My red tail black shark was the last fish to go into my 50 gallon tank. I already had 6 tiger barbs, 6 harlequin rasboras and three clown loaches. At first my tiger barbs nipped at his fins but he soon put a stop to that by chasing them and nipping them back. So now they all live together peacefully and he seems to be good friends with my clowns, sharing the cave with them he doesn't seem to be territorial at all until feeding time when he keeps all the other fish away from his favourite plant while he eats off it. I love my new shark and would recommend anyone with clown loaches getting one. Hours of entertainment.

From: Dave
My red tail liked to jump up into the filter when I first got it. I think it is too big now but it use to swim quickly against the flow coming out of the filter and jump inside the filter box. I noticed this one day when he was missing. I thought for sure he had jumped out but to my suprise I looked inside the filter box and there he was.

From: Gee
I have a red tail shark and pretty much he is the only fish that has survived out of all the fish I started with. He is the sole survivor as you put it. I have it in a tank with tetras, and catfish. He and the catfish seem to have it out every now and then, but other than that, he's fabulous and my favorite.

From: Inch Worm
I have a red tailed shark with two clown loaches in a 20 gallon. They swim together as a group and seem to be best buds. I have tried to add other fish (i.e. larger rainbow shark, gold barbs, and cichlids), and have had to remove all eventually after my much smaller red tail attacked all of them. I am planning to upgrade to a 90 gallon tank soon and hopefully then I could keep other fish. I have managed to keep several ghost shrimp without trouble. He seems to patrol the tank while the loaches eat and runs off all others that come looking for food. He seems content to scavenge the leftovers. My favorite fish!

From: Katy
I have two red tail sharks and they actually enjoy each others company. I took one out to quarantine it because it got Ich and the other one seemed a little lonely and was searching for its friend. Maybe I got lucky? They are great fish to have. I would recommend them to anyone.
FishLore: You have been lucky and this experience is not the norm. Most of the time they will not tolerate each other's company.

From: Matt
My Red Tail is in a 20 gallon tank with a number of tetras, catfish, and a Betta... worst combination ever? Surprisingly no. They get on considerably well for both being agressive fish. They'll have a wee nip at each other if they get too close, but they mostly tolerate each other.

From: Ray
I have a red tail shark and he has been very aggressive in the past. He used to live in a 29 gallon tank but I have him in my 75 gallon tank now. There is a yellow severum that about 10 - 12 inches and a 7 inch chin strap and another fish that I don't know what it is, but its about 6 inches and a cichlid of some kind and 6 giant danios, a common pleco and a blue botia. The botia and the red tail are about the same size (4 - 5 inches) and they sometimes fight. I never had any problem with the red tail jumping out. He is a beautiful fish.

From: Bridget
I didn't know about the jumping thing, so that's a handy thing to know! But I definitely found that from the time I entered my Red-Tail into my tank with a couple of Barbs, he made a cave his home and is very territorial over it! I definitely recommend putting something in your tank for your Red-Tail to hide in!

From: King Dojo
I first got my redtail shark about 5 months ago and he is already 4 inches. He is great for cleaning algae off plants and is not a fussy eater. When I got him he was in a tank with about 15 others in a LFS and they all were busy chasing each other around. So I thought this was common playful behaviour and got two. I soon relized it wasn't and the dominant one harrassed the other one till it was dead. So now I know. I also got an albino red finned shark and he also harrassed it to no end. But now that there are no other kinds of sharks he is satisfied to just try and intimidate the venustus cichlids. He's the king of the tank and the albino red finned shark is happy in his new home.

From: Justin

I have 2 red tailed sharks, 2 rainbow sharks, a rhino pleco, common pleco, 2 koi's, 6 tiger barbs, 4 freshwater crabs and a blue freshwater lobster in a 60 gallon tank.

At first the fish all got along fine, then one of the red tailed sharks basically took over the tank bullying everyone. One of the koi nipped his fin and now he won't bother them anymore. Yet "Maverick" as I call him torments the other sharks relentlessly. I think I may take him out and put him in his own tank with an oscar and a pleco.

I have lots of hiding spots, but maverick still seems to run everyone out of them. I wouldn't put redtailed sharks in pairs or even more then 1. Let this beautiful fish be a loner.

FishLore: Thanks for the comment, but I'm sorry to say that your 60 gallon tank is way overstocked. Koi is a coldwater species and mixing tropicals with coldwater species can stress out the coldwater species if the tank temperature is kept too high, not to mention the waste loads generated. Koi can reach 2 - 3 feet in length as adults and the plecostomus can get over a foot in length. Also, an adult Oscar may look at the red tail shark as a nice snack. Yikes - please research before buying fish.

From: Steve
These are great fish, one of my favorites but they are semi-aggressive and anyone introducing them must realise this. Mine is a female (it has a grey stomach so I presume it's female) and is highly active and getting big. She chases anyone that goes anywhere near her lair (a plastic pagoda ornament lol). She has never harmed or killed any other fish. It is purely for show, but I will warn you, mine absolutely despises the two silver shark I have and chases them when ever she sees them. This may not be the case with all of the species, but it's something to take into consideration. Overall a great fish that I highly recommend.

From: Anna
I have a red tail in a 60 Liter tank with a silver shark, a couple of rock shrimp and a few glowlight tetras. To begin with my red tail would chase the silver shark but he doesn't bother so much any more; sometimes they even seem pretty friendly. They are territorial though and he likes hiding in his little castle.
FishLore: Anna - a 60 liter tank (around 15 gallons) is going to be much too small for your silver shark Balantiocheilos melanopterus. Please consider getting a much larger tank or return the silver shark. They needs lots of swimming room and can get much too large for a 60 liter aquarium.

From: Kevin
I have had my RTBS for over 9 years. He is about 4.5 inches long and I have had him in a 35 gallon tank for the last 7 years. He was less than an inch when I got him and I kept him in a plastic tank on my dresser. He has out lived all my other fish. He's great, I highly recommend having this fish in your tank.

From: Heidi
I recently moved my Red Tail to a different aquarium in my bedroom. When I woke up this morning, no shark. He was a jumper. Jumped out last night and we didn't find him in time. RIP 07/13/07

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