Guppy Losing Tail, Scales & Fins: Reasons & Solutions

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Guppies are relatively hardy creatures, which is why they are so popular among fish keepers. However, sometimes they develop conditions that raise some concerns. For example, more than once, I have noticed that the guppies in my tank begin to lose their tail, fins, and sometimes even scales. To treat the conditions, I started to investigate the topic extensively.

Guppies typically lose external organs like fins, scales, and tails due to direct collisions within the tank or a bullying tankmate, which nibbles their body parts. However, that could also happen due to an underlying disease, such as fin rot and scale shedding, secondary to bacterial infections.

As we move forward in this article, I will show you how to treat guppies that lost those essential organs. That includes treatments for severe diseases such as fin rot and scale shedding, which could quickly spread and attack your entire tank.

Also Read: Guppies Diseases

Why Do Guppies Lose Essential Organs Like Tail, Scale & Fins?

Guppies are not snakes. You shouldn’t expect them to shed their scales, and neither is it normal for them to lose tails and fins. Unfortunately, guppies lose these vital organs all the time. That should raise a concern. Fish rely heavily on their scales for protection. They also use their fins and tails for swimming properly.

The absence of these organs weakens your guppy, leaving it vulnerable to attack from predators, diseases, and injury. If your guppy’s scales, fins, or tail are gone, these are the most likely culprits:

1. Direct Damage

Fish can lose their external organs by colliding with or rubbing against the objects in their tank. That includes rocks, pots, plants, and any other sharp-edged decorations they encounter.[1] Sometimes, these collisions result in frayed fins and split tails. 

On other occasions, guppies can lose entire sections of their fins, tails, and scales. If you think your plants and decorations are safe, analyze the nets you use to handle your fish.[2] That could be the case if you recently moved your guppy from one place to the other.

You should also check the appearance of the rest of your fish. If more than one fish had lost its external organs, it is likely to be in the tank itself. Try looking for residues on the substrate. If sharp objects are to blame, you will probably see it right away.

2. Bullying Tankmates

Aggressive fish are just as common as physical damage, where the loss of scales, fins, and tails is concerned. They will either nip at the fins and tails of your guppies, removing small chunks at a time, or bite the organs off altogether.

If the encounters between your guppies and their neighbors escalate, the guppies could eventually lose their scales. Stand by your tank for a while and watch how your guppies interact with their companions. Sometimes aggression could manifest between the male guppies themselves.

3. Underlying Disease

In the absence of sharp decorations, erratic swimming, and violent encounters in the tank, you should consider the possibility that your guppies have contracted a disease. The diagnosis will depend on the organ that has been afflicted:

Fins and Tails Diseases

If the fins and tail are falling off, fin rot is the most likely cause. Imputed to Vibrio bacteria and fungal infections, fin rot starts by discoloring the infected organ’s edges. Over time, the ailment will consume small sections of the fins, causing them to fall off.[3]

If left untreated, fin rot can destroy the entire organ. Vets usually blame fin rot on low water quality and fluctuating temperatures. Even if fin rot is not the case in your tank, you should act to treat it to prevent further damage.

Scales Diseases

If your guppy’s scales fall off, one potential culprit is scale shedding disease, an illness caused by bacteria (Aeromonas punctate and Pseudomonas fluorescent).[4] In the early stages of scale shedding, the scales will protrude from the skin according to the pustules that have formed beneath. 

Eventually, the scales will fall off. The disease can attract additional symptoms such as labored breathing. Because other bacteria can cause ailments with similar symptoms, you need a vet to examine the fish before you conclude that your guppy has the scale-shedding illness.

Also Read: Why Is My Guppy Fat?

4. High Current Filters

Depending on your guppy’s size and strength, it could lose its organs to a powerful filter. Some people argue that a filter can only strip your guppy of its fins if it can’t swim fast enough for some reason and if the fins are already weak. 

For instance, if they are already infected with fin rot. However, that could also happen if your guppy is pushed against objects in the aquarium. Regardless of the reason, filters are a danger you should account for before introducing guppies to the tank.

Treating Guppies That Lost Their Tail, Scales & Fins

Fish are not like humans. For these creatures, losing fins, tails, and scales isn’t necessarily comparable to losing a limb. That is why they don’t always show signs of distress. In some cases, the guppy fish will swim as if nothing has happened.

That being said, you are still expected to take specific steps to treat a guppy that has lost its vital organs. Otherwise, the guppy could suffer further harm down the line. For example, it could be harassed by its tankmates. To prevent this, I suggest considering the following:

1. Allow Natural Healing

Guppies don’t always react to losing their fins, tails, and scales with distress because they can grow back. The duration will vary depending on the fish’s health, age, and extent of the damage. But in many cases, a guppy can regrow these organs in a few weeks:

The creatures have a small number of cells to direct the growth of new fins and tails. They also have genes that stop this process, preventing an organ from growing beyond its original size. That creates an essential balance in the healing process.[5]

That is good news because guppies use their fins and tails for swimming. The absence of these organs can debilitate a guppy’s control over its movements in the water. However, that doesn’t apply to every fish. 

Some fish can swim just as competently without their fins and tails. But if they had a choice, they would prefer to have them. However, keep in mind that in some cases, fish cannot swim as quickly or powerfully with regenerated fins as they did with the original organs.[6]

Scales are in the same boat. While they will regrow, there is no guarantee that they will regain their original color. Either way, I suggest that you wait a couple of weeks to see if the guppy heals on its own. You may also take pictures to prove its recovery.

2. Fin Rot & Scale Shedding Treatments

To treat fin rot, you must address the root cause, which is typically low water quality. I recommend performing partial water changes more frequently. Start by exchanging 20-30% of your water weekly. You may lower it to 10-20% after a while. 

You should also vacuum the substrate and remove all the leftovers. The accumulation of those could be toxic in the long haul. Then, test, monitor, and maintain the pH and temperature. Keep the pH between 6.8 to 7.8, and the temperature at 72 to 82 degrees F.

It would help if you also control the concentrations of toxins in your tank. For that, I highly recommend the API Aquarium Test Kit (link to Amazon). That is the most cost-effective bundle I could find so far. Within minutes, it will measure the pH, nitrates, nitrites, and ammonia in your tank. If too high, it would be best to perform more frequent water changes. 

Bear in mind that the wrong parameters will induce stress, an element that will exacerbate your guppy’s condition, slowing the rate at which it recovers. I also suggest consulting vets. If you don’t have one nearby, you could try antibacterials like Melafix (link to Amazon). 

Yet, you are still encouraged to consult a vet because the wrong antibiotics could create antibiotic resistance. If the Melafix doesn’t seem to make any difference, do not reuse it. You probably need something else at this point.

You can treat a guppy scale shedding using violet K and antibiotics such as Biomycin and sulfanilamide.[7] However, you can only treat fish with this disease in the early stages. If you allow the illness to advance beyond a certain threshold, it will become incurable.

3. Prevent Further Physical Damage

It would be best to remove any objects and plants in the tank that can harm your guppies. If you can’t determine whether an object is dangerous, run a pair of pantyhose over it.[8] If the pantyhose snag and tear, your guppies will suffer a similar fate.

Regarding the handling of guppies, you should use nets with fine mesh and smaller holes.[9] Nets with a coarse mesh and large holes will harm the fish, stripping them of their scales. Generally, cups are a better choice than nets in moving fish.

4. Pick the Right Tankmates

Keep your guppies with fish like the Bristlenose pleco, Rasbora Fish, and Bettas with whom they can co-exist peacefully. Avoid species like Oscars, African cichlids, and Flowerhorn fish that can oppress and harm their tankmates.

Generally, it would be best if you avoided fast swimmers who could effortlessly chase down your guppies, nipping on their fins in the process. The best way of choice here is observation. Watch and see which tankmate bullies your guppy and move it to a separate tank.

5. Feed Your Guppies Properly

A guppy that has lost its fins, tail, or scales requires a balanced diet consisting of high-quality meals. That includes brine shrimp, flakes, daphnia, and bloodworms, to mention but a few.[10] A well-fed guppy will recover from diseases like fin rot at a faster rate, not to mention regrowing its organs quicker.

Feed your guppies a balanced diet and avoid relying on pellets solely. Feed your guppies twice a day, and no more the amount they consume within two minutes. That will prevent leftovers from accumulating in your tank, raising ammonia and nitrates.

If that is too much to remember, I highly recommend checking the Eheim Automatic Feeding Unit (link to Amazon). That is the most accurate device I have been able to find this far. It will feed your fish the precise amount you set while maintaining the right intervals.

6. Aquarium Salt

Aquarium salt has several uses. Where lost fins, tails, and scales are concerned, the salt will prevent infections from setting in before the organs regrow, mostly if they were lost due to an injury.

To use it, you should create a hospital tank that will host the sick guppy. Then, pour one tablespoon of aquarium salt into each gallon of water. It is essential to maintain this ratio so that your guppy doesn’t suffer any further damage.

Also Read: Why Does My Guppy Have White Poop?


It is quite prevalent to witness a guppy fish that has lost parts of its body. In most cases, external organs such as scales, fins, and tails suffer direct damage. That could happen when the fish collides with decorations, for example. In other cases, it might be a bullying tankmate.

However, if you ruled out those options, you should consider bacterial infections that could cause fin rot and scale-shedding diseases. At this point, you should quarantine your fish and treat it with antibacterials and salt. Consulting a vet is also necessary to prescribe the right treatment.