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Is My Red Tail Shark Sick? (Common Signs to Look For)

Is My Red Tail Shark Sick? (Common Signs to Look For)

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

With their black bodies and contrasting bright red-tails, red-tail sharks are an excellent choice for adding an exotic feel to your home aquarium. If your beloved red-tail shark has been acting abnormally lately, you may be asking yourself: is my red-tail shark sick?

You red-tail shark could be indeed sick. The most common diseases for red-tail sharks are Ich and fin rot.

The former is a parasitic infection that causes white spots on a red-tail shark’s fins and gills, and the latter is a bacterial disease that causes fin discoloration and deterioration. Both are fatal if not treated promptly.

Read on to learn more about how you can tell if your red-tail shark is sick. We’ve also included useful tips on how to treat a sick red-tail shark.

Red-Tail Shark Overview

Here are some key facts about red-tail sharks:

Scientific NameEpalzeorhynchos bicolor
Adult Size6 inches (15 cm)
Natural HabitatStreams in South Asia
Required Tank SizeMinimum of 36 inches
CommunityOnly keep one red-tail shark in an aquarium
Best ForIntermediate and expert owners

Typical Red-Tail Shark Behavior

You won’t be able to tell when your red-tail shark is sick unless you know how these fish normally behave.

Adult red-tail sharks are notorious for their adversarial temperaments. These fish are serious about their territory. Once they establish it, they fiercely protect it by chasing away any other fish that try to enter.

Also, red-tail sharks are highly active. They can typically be found darting around their tank at high speeds.

If your red-tail shark is still young, it’ll behave a bit differently. Young red-tail sharks spend a lot of time cooped up in hiding places to feel safe.

Additionally, red-tail sharks are nocturnal fish that reach peak activity at night.

How Do Red-Tail Sharks Act When They’re Sick?

If you feel that something is off with your red-tail shark, there are several indicators to look out for to gauge if your fish is sick.

These indicators may be behavioral, or they can be related to your red-tail shark’s appearance.

The main behavioral changes that occur when a red-tail shark is sick are lethargy and a loss of appetite.

Since red-tail sharks are typically extremely active, you’ll easily spot when something is amiss when your fish isn’t moving around much. Sick red-tail sharks will also appear disoriented when swimming around the tank.

Additionally, reduced appetite is a symptom that several diseases, such as Ich and fin rot, have in common.

However, if this is the only abnormal behavior your red-tail shark is exhibiting, it may simply not care for the food you’re giving it. Try feeding it something different and see how it reacts. If your red-tail shark is rejecting all foods, then it’s probably sick.

Common Illnesses for Red-Tail Sharks

Red-tail sharks can develop any of the various diseases that plague freshwater fish.

The most common diseases for red-tail sharks are Ich and fin rot. However, they can also contract other freshwater fish illnesses, such as popeye.

Here are the details of each of these diseases:


This is a parasitic disease that can be life-threatening to your red-tail shark if it isn’t treated in time.

The parasite attacks and feeds off your shark’s fins and gills, causing its overall health to rapidly deteriorate.

The main sign that your red-tail shark has Ich is the presence of white spots all over its body. These spots are likely to be concentrated in the fin and gill areas.

Another tell-tale sign of Ich is your red-tail shark constantly rubbing its body against objects in its tank. This behavior is your fish’s attempt of getting rid of the parasite.

What to Do?

Since Ich is a highly contagious parasitic infection, you should remove the infected fish from the aquarium immediately and place it in another tank.

The main treatments for Ich are anti-parasitic medication and raising the water temperature in the tank. Both these measures act to kill the parasite causing the illness.

Fin Rot

As the name suggests, fin rot attacks your red-tail shark’s fins. This bacterial disease also affects red-tail sharks’ tails.

If your shark has fin rot, you’ll notice that the bases of its fins are inflamed. You’ll also find white, black, or brown discolorations on its fins or tail. Another symptom of fin rot is your fish developing ragged edges on its fins due to deterioration.

Like Ich, this disease is also fatal to your red-tail shark if you don’t address it promptly.

What to Do?

The best way to treat fin rot is to use anti-bacterial medication.

A great example of such medicine is Melafix. You can apply this medication to your red-tail shark’s water to get rid of the bacteria responsible for fin rot.


This disease isn’t as common in red tail sharks as fin rot or Ich. However, popeye is still an illness to look out for when caring for a red-tail shark.

Popeye is a relatively easy disease to spot. Considering that it affects your shark’s eyes, this condition literally stares you right in the face. It causes dysfunction in the blood vessels of your red-tail shark’s eyes sockets.

As a result, your fish’s eyes bulge excessively and may ultimately fall out.

Popeye isn’t a fatal disease. However, you should still address it as soon as possible.

What to Do?

Your course of action depends on how far the popeye has progressed.

If it’s still in the early stages, you can curb the eye swelling by adjusting the aquarium conditions to healthier levels. Additionally, giving your shark the right food can go a long way.

If it’s too late for this, your best bet is antibiotics, Melafix, or Epsom salts.

What Causes Red-Tail Sharks to Get Sick?

The main factor that causes sickness in red-tail sharks is their tank conditions.

The water in your aquarium contains plenty of bacteria. This is completely normal and usually isn’t a cause for concern. However, that changes when your red-tail shark is constantly in a stressed state due to sub-optimal water conditions.

This increased stress weakens your red-tail shark’s immune system. In turn, it makes the fish more prone to diseases, bacterial or otherwise.

How to Prevent Your Red-Tail Shark From Getting Sick

You know what they say, prevention is always better than cure. Your red-tail shark’s health is no exception. You can greatly reduce the likelihood of it getting sick by ensuring that its living conditions are up to par.

Relative to other species, red-tail sharks are quite durable and can withstand a variety of conditions. However, these are the optimum surroundings for this species:

  • Water temperature: 75°F
  • Water pH level: 6.5 to 7.5
  • Water hardness: 10 to 15 KH

Make sure to consistently monitor the aquarium conditions to maintain the parameters listed above. You can do so using an aquarium testing kit.

Additionally, ensure that you’re providing your red-tail shark with a diet consisting of the correct balance of vitamins and nutrients it needs. Doing so will keep your fish’s immune system sharp and keep it safe from illness.

Final Thoughts

If your red-tail shark hasn’t been as active as usual lately, you may be wondering, is my red-tail shark sick?

If the conditions in your aquarium are subpar, your pet shark may have developed diseases such as fin rot and Ich. Both of these conditions are serious and warrant immediate attention. Failing to treat your red-tail shark promptly may prove to be fatal.

The main cause of disease in red-tail sharks is their aquarium water not being at the right temperature and pH level. Subpar water conditions stress out the fish and weaken their immune system.

Use the tips and guidelines outlined in this guide to keep your red-tail shark in tip-top shape.

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