Are Red Tailed Sharks Aggressive?

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You don’t always get the chance to keep a shark in your home tank, which makes the red-tail shark that much more valuable.

This black and red fish is a peculiar one because it’s omnivorous, preferring a plant-based diet for the most part, but comes with predatorial instincts.

Red tail sharks won’t hesitate to consume small invertebrates and small fish if given the opportunity. They are also notoriously territorial and aggressive, making them a tough choice for community setups.

Today, we will discuss red tail sharks and whether you can house them with other aquatic animals. We will also discuss potential strategies to disarm the fish’s fiery temperament, making it more reasonable and manageable.

So, let’s get to it.

Reasons Red Tail Shark is Aggressive

Several reasons can cause the red-tail shark to exhibit extreme aggression:

  • Not enough space – This highly territorial animal won’t accept other fish patrolling its space. You should have at least 55 gallons for one 6-inch red-tail shark, preferably more in a community tank. I would go at least 70 gallons, depending on what other types of fish you have.
  • Not enough food – A hungry shark is a cranky shark. This species requires a balanced and diverse diet consisting of plant-based and animal-sourced foods. Cucumbers, peas, zucchini, some fruits, and animal protein from sources like daphnia, krill, brine shrimp, and fish meat make for a well-rounded diet. Make sure that the shark eats at least once every other day and offer protein-rich treats 1-2 times per week, depending on the specimen. Don’t overfeed your shark, or it will develop digestive issues, which will boost its crankiness significantly.
  • Incompatible tankmates – You need to pair your red-tail sharks with semi-aggressive species that won’t be intimidated by the bully. Slow swimmers with a docile and non-combative attitude will sometimes be attacked and even killed. The ideal tankmates should be at least as big as the shark and showcase an active temperament.
  • One shark per tank – Housing 2 red tail sharks in the same environment is set to spell disaster. These fish are notoriously aggressive towards each other and often fight to the death over territorial disputes. This is one of the reasons why red tail sharks are almost impossible to breed in captivity.
  • Fish stress – Your red tail sharks can get stressed for a variety of reasons, including insufficient or bad food, sickness, parasites, overly aggressive tankmates, overcrowding, etc. The fish tends to showcase a variety of symptoms, in this case, aggression being one of them.

How to Deal with Aggressive Red-Tail Shark?

The solution to your shark’s aggression depends on the triggers. First, you identify what’s causing the fish’s extreme aggression in the first place.

Only then can you decide on the right course of action.

Some basic recommendations include:

  • Feed your shark more frequently – While the general feeding pattern is one meal every 2 days, not all sharks abide by this rule. Some come with healthier appetites and require more frequent meals. If your shark seems too aggressive, feed it once daily and see if that changes its behavior.
  • Increase the tank size – This usually works wonders, as sharks need space above everything else. Overcrowded red-tail sharks are more prone to exhibiting territorial aggression, attacking and even killing other fish.
  • Watch for signs of disease – Always look for signs of parasitic or bacterial infections that could alter your shark’s behavior. The increased aggression is typically the first sign that sharks are stressed and dealing with health issues.
  • Manage water parameters properly – The ideal red-tail shark temperature is 71-80 F. If the temperature drops too low, the shark will have problems digesting its food which leads to constipation and bloating. This causes the shark to become stressed, and we’ve already determined where that goes. If the water is too hot, the fish will become restless and attack its tank companions.
  • Add more decorative elements – Sometimes, you can mitigate the shark’s behavior by simply adding more plants, rocks, and other decorative pieces into the environment. These act as hiding spots, breaking the line of sight between the shark and its companions and reducing the likelihood of violence.

Finally, if nothing works, you have 2 options left: remove the shark or remove its tankmates. Your choice depends on which of the 2 you value the most.

If you value your red-tail sharks more, I recommend finding disposable and affordable tankmates that you can replace easily.

Keeping Red-Tail Sharks with Other Fish

Consider 5 pieces of advice when looking for the ideal tankmates for your red-tail sharks:

  • Prioritize schooling/shoaling fish – Schooling and shoaling fish group together to face any threat, a behavior that can intimidate the red-tail shark. This will decrease the shark’s aggression and increase its tankmates’ survival rates. Barbs and danios are ideal in this sense.
  • Manage the habitat wisely – More hiding spots. The 3 best words to consider when preparing your red-tail shark for a community setup. Just make sure you don’t overcrowd the tank with too many decorative elements. Red-tail sharks still require plenty of open space for swimming and exploring their habitat.
  • Prioritize semi-aggressive species – You need some fish with attitude, as docile and timid fish make for poor choices; they will simply be bullied into oblivion by the shark. Don’t overdo the aggression, as it can backfire, causing the more aggressive species to bully the shark instead. So, stay away from African cichlids.
  • Different swimming areas – You should prioritize fish species that prefer different swimming areas. Bala sharks are great in this sense. They are large and prefer to dwell near the surface, decreasing the likelihood of shark-on-shark violence.
  • Fish size – Skip small fish like tetras which are likely to become food for your shark. The ideal tankmates should be at least 3-4 inches in size.

Ignore invertebrates completely, no matter their size. The shark will hunt them down and eat them.

Will Red-Tail Shark Kill Other Fish?

Yes, it will. It depends on the fish, but red-tail sharks won’t hesitate to attack, hurt, and kill other fish species if possible.

Do Red-Tail Sharks Eat Shrimp and Snails?

They most certainly will. Red-tail sharks have shrimps on their menu, but they’re not that fond of snails. If they would, red-tail sharks would be even more popular than they already are.

Shrimps are an entirely different story, as red-tail sharks are known to consume any shrimp species, no matter the size.


In essence, red-tail sharks have aggression in their genes. You can’t really do much to change that, but you can mitigate their tendencies a bit.

I hope today’s article can help you in this sense.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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