It’s likely that you’ll find caring for hatchetfish to be rather easy. They’re not fish that are too tough to care for overall.
Generally, hatchetfish are hardy fish that aren’t too fussy. They can still encounter problems with certain diseases, though.
Below, you’ll learn about many of these common diseases. After learning about them it’ll be simpler to remain vigilant and to try to prevent these issues from occurring in your tank.
1 – Ich
Ich is a parasitic infection that is sometimes called white spot disease. White spots appear all over the fish.
These white spots are actually the parasites themselves. Fish usually only get this disease when they’re kept in poor water conditions.
There are many symptoms to look out for aside from the white spots. Fish that contract ich will become sluggish and they’ll often stop eating as normal.
You’ll likely see the fish rub against objects in the tank, too. You want to take action to help the fish as fast as you can.
Treating this condition involves making changes in the tank and using medication. Fix problems with the water parameters and raise the temperature of the water to the upper limit of what the hatchetfish will tolerate.
Using aquarium salt can help the fish to recover while inhibiting the parasite. There are many medications that can be given to the fish that will help them to get better as well.
2 – Dropsy
Dropsy is a disease that causes fish to have swollen bellies. Fluid accumulates in the body and causes the belly to swell.
There are other symptoms to look out for than the swollen belly. Sometimes fish with this disease will experience ulcers.
It’s also common for hatchetfish to have protruding scales when they’re dealing with this problem. The fins and vent might become very red, too.
You can treat the fish by giving them antifungal medications and using aquarium salt. This should help to clear up the fluids, but you need to focus on fixing issues with water quality in the tank as well.
3 – Hole in the Head Disease
Hole in the head disease is terrible because it makes your fish look like it’s dying. The fish could very well die if you don’t treat this condition.
This disease is characterized by lesions forming near the head of the fish. The holes in the fish’s head will get larger over time and you might notice yellow strings of mucus protruding from them.
When fish have this disease they will stop eating. They’ll become sluggish and will often try to hide in the tank.
You can treat this condition with various medications. It’s common for fish owners to treat fish with Metronidazole, but you can also use medicated foods.
Hole in the head disease is said to be caused by a parasite known as Hexamita. Fish are more likely to get this disease when the water quality is poor so focus on taking good care of the tank to prevent future outbreaks.
4 – Fin Rot
Fin rot is another condition that you want to treat fast to protect your fish. If your fish shows signs of fin rot you’ll need to take action right away.
This is a bacterial infection that eats away at the fins. You’ll notice that your fish will develop ragged fins.
The condition starts on the edge of the fins and then continues to spread. The presence of certain bacteria in the tank will cause this condition.
If you act fast you can cure the fish by giving it the right medications. Fix water quality problems and then treat the fish using antibiotic or antifungal medications.
Aquarium salt also proves useful when helping fish to recover from fin rot. Be sure to feed the fish well and nurse it back to health.
5 – Mouth Fungus
Mouth fungus is something that commonly impacts marbled hatchetfish. You’ll see fungus start to appear near the mouth of the fish.
The fungus has a cotton-like appearance. This is why this condition is sometimes referred to as “cotton fungus” or “cotton disease.”
Commonly, this fungal infection will impact fish that are exposed to poor water conditions. Temperature fluctuations can also stress the fish and make them susceptible to this infection.
You can treat the disease by giving the fish antifungal medications. It’s also important to fix any problems in the tank.
6 – Gill Disease
Gill disease is usually caused by infections from either bacteria or parasites. The gills become infected and this leads to the fish having a tough time breathing.
You might see the gills become swollen over time when fish are dealing with this issue. When looking at the gill filaments you’ll see that they’re discolored.
The fish might produce more mucus than usual when going through gill disease. It’s common for fish to experience rapid breathing as well.
Your hatchetfish will likely stop eating until the problem is solved. It might even stop moving if things are really bad.
As usual, fixing water quality problems helps to solve this issue. Do water changes and ensure that the water parameters are where they need to be.
Treat the fish by giving them medications such as antifungal medications or copper treatments. Try to focus on keeping the water quality high in the tank moving forward.
7 – Swim Bladder Issues
Swim bladder issues can impact hatchetfish as well. This isn’t really a disease, but it’s something that causes the swim bladder to malfunction.
For example, you could overfeed the fish and this will cause it to become constipated. The fish’s belly will swell and this makes it so the swim bladder can’t function normally.
A swim bladder is an organ that controls buoyancy in fish. It’s a gas-filled sac that needs to be able to inflate and deflate as necessary.
When the belly is pressing against the swim bladder it won’t work right. So you need to solve the constipation problem to get the fish back to normal.
Swim bladder issues make it so that fish can’t swim properly. They might swim in circles or swim upside down when they experience swim bladder malfunctions.
Sometimes infections will cause the belly to swell, but it could simply be related to constipation. It’s recommended to use aquarium salt and antibiotics if you suspect that the fish has an infection.
8 – Pop Eye Disease
Pop eye disease involves one or both of the fish’s eyes bulging out of the socket. This is an infection of the eye area.
It can be caused by a physical injury to the eye, but it could also be related to bacteria in the tank. Even parasites have the potential to cause pop eye disease.
If the cause is bacterial in nature, you’ll need to do water changes and give the fish medication. Sadly, fish will sometimes lose an eye due to experiencing this problem.
Aquarium salt can also aid in the healing process. If you treat the fish it should survive and get back to normal.
Now you know about many diseases and problems that you should watch out for. Do your best to keep your eyes open for these problems when caring for hatchetfish.
Some of these diseases have the potential to kill the fish. If you ignore the symptoms and don’t treat the fish they might wind up passing away.
Luckily, proactive fish owners are going to be able to save the fish. You can recognize the symptoms and then give the fish appropriate treatments to turn things around.
Some hatchetfish diseases are more problematic than others, but even gruesome conditions such as hole in the head disease can be treated.
Continue to pay attention to your fish moving forward. This will allow you to make good choices and keep your fish in good health.
You can prevent your fish from getting sick by taking good care of the tank. When the water quality is pristine it’s less likely that the fish will become ill.
Jeff has always enjoyed having pets, but as a child, he was drawn to his family’s fish tank. Being able to maintain a small ecosystem and observe the behaviors and interactions in the underwater world peaked his interest early on and has kept him hooked until this day. On Avid Aquarist, Jeff shares everything he’s learned about helping aquatic life survive and thrive in a home aquarium.