5 Signs Your Molly Is Dying (And What You Can Do)


When your fish encounter problems, you can’t help but wonder if there’s a way to help them. If your Molly’s health is suffering, it would do well to identify if the cause is natural or unnatural, and if the problem is fixable or not.

How Do You Know If Your Molly Fish Is Dying?

Sign #1: Unusual behavior

The first sign that tells you something’s wrong is that while everything looks fine physically, your Molly is not acting like its usual self. It might lose its appetite and have changes in diet, hide, look sad, stay at the bottom of the tank, or shaking or shimmying.

If your gut tells you something’s off, check on the tank environment like changes in water quality and temperature immediately. Most of the time, a partial water change does the trick, and everything goes back to normal soon after.

Some people use Mollies to cycle their aquariums because these fish create a lot of waste. And while many survive the struggle of ammonia and nitrite spikes, some don’t. That’s why we recommend doing a fishless cycle instead as there are other things (mostly non-living) you can use to age your water. Gasping for air and inflamed gills are proof of ammonia poisoning.

Sign #2: Disease symptoms

Physical (and more obvious) indications on your Molly Fish would be difficulty swimming or lying on its side, white or black spots on its skin, lesions, swelling, pointed scales, fin rot, red mouth and anus, gasping for air, and tumors.

Look up the symptoms right away and provide the right treatment to cure the illness. Don’t wait until the condition gets worse.

Sign #3: For a Balloon Molly, the curved back gets worse over time

One particular trait Balloon Mollies have is their curved spine. This is a genetic defect that the species adjusted to by developing a balloon-like shape to survive. Instead of getting shunned, the Balloon Molly gained a lot of popularity for this ‘cute’ appearance, urging breeders to produce more.

5 Signs Your Molly Is Dying
5 Signs Your Molly Is Dying

Some curves are slight, some are more pronounced, and some get worse. This is why many fish owners say Balloon Mollies have shorter lives than other types of Mollies.

Balloon Mollies are also prone to issues like constipation and swim bladder disease. Unfortunately, this doesn’t get spotted right immediately because its shape and behavior don’t give it away at early onset.

There are many healthy Balloon Mollies, but there will always be those that aren’t. Sadly, they are big money-makers for breeders so there’s no end in sight for their production.

Sign #4: Mommy Molly exhaustion

There are some cases when female Mollies die after giving birth mainly because of exhaustion. The effort of labor plus the males trying to chase her before and right after her pregnancy causes lots of stress. She might isolate herself, get aggressive, refuse to eat, or get sick.

Sign #5: Old age

Mollies live an average of 4 to 5 years depending on their breed and care. No matter how good a hobbyist you are, fish will pass on if they’ve lived full lives. Even without disease, fading color, slower movement, and cloudy eyes are indicators of old age.

How Do You Revive A Molly Fish?

Tip #1: Do a fishless cycle

You don’t have to risk your Mollies just to cycle your tank. The best way to cycle your tank quickly is to use fully cycled media that already contain these beneficial bacteria. Since sponge filters contain a lot of these, so just use one from a long-running tank.

If you don’t have access to one, it might help to create a couple of these cycled filters for the future. Once your tank is established, add another sponge filter that you can pull out whenever you need one for, say, a hospital tank or a breeder tank.

Going back to cycling your main tank, make sure that you don’t put too much bio-load for a newly-established tank. Adding too many Mollies and then experiencing change in ammonia levels could have lethal consequences.

Tip #2: Regularly check and clean your devices

Spot a busted heater or a clogged filter before they cause trouble. Along with your monthly general cleaning or your weekly water changes schedule, make sure your temperature reading is accurate and your filter is working fine.

If you don’t have the master test kit that uses tubes, get one! You can still use the test strips for your regular checks, but use the master test kits when you think there’s trouble.

Tip #3: Early diagnosis of disease

Just like with any living organism, early detection of disease helps mitigate symptoms and complications. There’s a bigger chance of recovery if these diseases are treated right away.

Tip #4: After giving birth, female Mollies should be put in a recovery tank

Separating the female Molly will help her recover and not have to face the aggression and energy of males chasing her around. She must be kept in a recovery tank and fed protein-rich food (bloodworms, daphnia, brine shrimp, etc.) for about a week before you put her back with the rest of your fish.

Tip #5: Separate Molly fry

Molly fry should be birthed and kept in a separate tank if you want to save them. If not, they’ll be eaten by adults in the community tank.

This growout tank should also contain a sponge filter. Power filters have the potential to suck the fry and kill them.

And while lots of feeding is important as these fry grow, overfeeding will cause death. Instead of dumping lots of food one time, feed the fry 3 to 4 times daily with little amounts.

Tip #6: Don’t use Balloon Mollies as dither fish

Dither fish are often used by hobbyists to distract bigger, more aggressive fish inside a community tank. When the big ones are distracted, it keeps the peace inside the aquarium.

Some Balloon Mollies are not as fast as Sailfins or Shortfins because of their irregular shape. Those with very prominent spine curvatures are slower and more prone to bullying inside a community tank. They won’t be able to get away as fast and might get hurt or eaten.

If you want to give a home to these unique and adorable Balloon Mollies, give them their own species-only tank or keep them with safer, less aggressive tank mates such as Tetras, Corydoras, Platies, or Loaches.

When You Can’t Avoid the Inevitable

Serious diseases like dropsy are very hard to recover from. If treatment proved futile, you’ll just have to wait it out while your Molly is in the hospital tank. Imminent death is obvious with fewer signs of life.

Dying Molly Fish
A dead Molly fish

You can choose to move your Molly into a hospital tank or wait it out in the community tank. Eventually, the fish will float on top of the water or stay lifeless at the bottom.

Remove dead fish from the water ASAP.

So You Did What You Could

Mollies don’t have to die before their prime, so do your best to avoid putting them in situations where they can be at risk.

Sometimes though, it’s beyond your control. In the case of diseases, trying to spot the problems early might save the Molly’s life.

If your fish is past the point of no return, it’s best to isolate and give it the best comfort you can in its final moments. Then learn from your mistakes (if any) and apply them to your new and existing fish. Write notes if you must so you can remember the lessons and so that others might learn from them, too. Experience and knowledge are what will make you a better fishkeeper.

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