Are Molly Fish Fin Nippers? Find Out Here!!

If you could get a fish that can live in freshwater and saltwater, how amazing could that be? And yes, you can have it when you go for molly fish. These cute bundles of joy are such peaceful, vibrant, non-schooling yet social fish that you cannot resist falling in love with their graceful activities in the aquarium. But every good thing comes with the rumors that are either true or false, and one thing about molly fish that is quite a debatable topic is if these fish nip the fins. So, are molly fish fin nippers? Do you have to take precautions to save your fish?

Sadly, yes, molly fish are fin nippers that are more likely to bite the fins of other molly fish and other tank mates. It’s common for one Molly Fish to nip at another in an overcrowded tank, and it can cause serious damage to their health if not addressed.

First, let’s talk about what a Molly Fish is. There are many different types of “Mollies.” However, in this post, we will only focus on the fin nipping habit of Molly fish.

Are Molly Fish Fin Nippers?

Molly Fish is always looking for ways to defend themselves. They use their fins to nip at predators and other Molly Fish who have been in the area too long or that they don’t like. If you happen upon a group of Mollies and one starts nipping at another fish, it is likely the nipping fish has a history of bullying, threatening, or is just looking to assert dominance.

What Causes Fin Nipping In Fish?

Fin nipping is the act of one fish biting another’s tail, fins, or body for no apparent reason. I know, molly fish is usually pretty cute, but fin nippers are a problem many people say they have.

However, there are some reasons why molly fish are fin nippers. Such as:

  • stress
  • boredom
  • overcrowding
  • fin nippers are territorial and might be trying to stake their claim on territory in the fish tank.
  • The outdoor event might damage the fins, such as a scratch against a rock or stepped on it.

Common Molly Fish Who Are Fin Nippers

All Mollies are not nippers. Other species, such as discus and guppies, may bite those who wear aquarium gloves or have their hands in the tank while feeding.

These types of molly fish may be the prettiest to look at all the time; however, these are also the type of fish that is most likely to nip at you if you handle them without care.

The common types of Molly fish that are fin nippers:

  • Guppy Mollies (Poecilia reticulata) have a pointed snout and are usually present in tropical, subtropical, and temperate areas.
  • Endler’s Livebearer (Poeciliopsis endless or Poeciliopsis Lucida) can be of any size and have a small head and a large stripe on their body.
  • Dwarf Molly (Poecilia Mexicana not) are usually brown or gray colored but can also be brindle with dark stripes.

Which Mollies Are Not Fin Nippers?

The most popular fin nipping fish is the goldfish because they have a long history of being aggressive toward other tank mates. These types of fish will bite their fins off as an act of dominance to establish themselves as the dominant fish in the tank.

However, some mollies do not fin nippers as well. Such as:

  • The black Molly
  • Albino molly
  • Holland Blue Mollie
  • White Molly
  • Tiger striped Molly
  • Gold molly.

Will The Fin Nipping Hurt Molly Fish?

Fin nipping in fish refers to the act of one fish biting or nibbling on another’s fins. Sometimes, this is a way for one fish to show dominance over another.

Other times, it may be due to poor water quality and lack of hiding places- these conditions can cause stress among the fish members living in a tank.

Fin nipping in fish can be a serious problem, and if you leave it without addressing it,  it may lead to the death of the fin-nipped or injured fish.

So pet owners need to notice when they see their mollies doing this because it could signify something wrong with the fish tank’s environment.

What Are The Signs Of Fin Nipping In Molly Fish?

You might see fin nipping in fish when one Molly has its fins bitten off by another, but it may also occur when they have nibbled gills or tails. Some tell-tale signs that your Molly may have fin nipping are when it has a raggedy-looking or torn-off tail, bitten off fins, and nibbled gills.

If another fish cut open your Molly fish’s body in attack, that can signify fin nipping. Fin nipping can affect the fish, depending on how severe it is, and attack part of its body. The signs may include:

  • Torn fin or tail (and often bits of skin around these areas)
  • Bitten gills 
  • Bitten fins
  • Open wounds on the body or head.
  • Torn or bitten off fins (in some cases, it can affect more than one fin) Coat of scales and skin around these areas damaged during an attack by another fish nipping at it.
  • Other fish often nibbles the gills of Molly fish
  • Lack of balance in fins

In some cases, fin nipping can lead to the death of a fish.

How To Solve Fin Nipping Problem In Molly?

Fin nipper fish are not sick, and they do not need medication. However, severe fin injuries may cause problems for the fish as they will have trouble swimming, leading to death. So, if you notice fin nipping in Molly, then you can use these steps to solve this issue:

  • First, regularly check the water quality.
  • Provide plenty of company for your fish by not leaving them alone in a tank.
  • Filling up the aquarium with live plants like those found here: Amazon link to the complete eco substrate
  • Cover all sharp edges on rocks and decor so that fins are less damaged.
  • Feeding each fish their food dish to have less chance of biting.
  • Add some plants and caves for them to hide in on the sides or bottom of your tank. This will give them more things to do, lessening boredom and preventing stress and overcrowding.
  • Putting a divider in the tank so that your fish can’t get to each other’s fins, and they also have less chance of biting because it’s not as much fun when there isn’t someone else around.
  • Cut down on feeding them live foods like worms or bloodworms (which many fin nippers seem to go for) and add more frozen or freeze-dried food.

What Does Fin Nipping Look Like?

Fin nipping in fish is when one fish bites or nibbles at the fins. It can also occur with humans and known fin nip, and it usually happens as a result of play-like behavior from children.

However, fin nipping mostly occurs on the backside of the body near the tail region—fish bites to establish dominance or out of aggression.

The impacts of fin nipping can vary depending on the severity and how often it happens. If the occurrence is frequent, the fish will lose its ability to swim in a straight line or may have trouble with the balance over time.

Fin nipped fish might also experience minor bleeding from wounds in close contact with other fish’s teeth and gums.

Will Molly Fish’s Fin Grow Back?

Molly Fish may have a fin nipping problem. It can happen to any Molly fish. It is prevalent in both Mollies with long and short fins. But, some species are more prone than others. 

One reason for bitten off or damaged fins could be the stress from overcrowding in a tank. Fin nipping also happens due to dominance struggles between Molly fish which may be related to territoriality and fighting for food or space.

Fin nipping is a destructive behavior that fish can exhibit. It doesn’t happen as often in saltwater fish. But it occasionally occurs and can cause serious damage to Molly Fish with fin-nipped fins.

Molly Fish can’t regain the shredded or bitten-off fins unless you take some necessary action for it.

How Can You Prevent Fin Nipping Problem In Your Molly Fish?

Fin nipping is not life-threatening to the fish. But it can be a frustrating and painful experience for them and an expensive one when you need to bring in a vet or specialist. For fin nipped Molly fish, there are some steps to prevent fin nipping problem are:

  • First, isolate the fish and make sure they do not feel overstressed.
  • Feed your Molly Fish a varied diet with plenty of protein, including feeder shrimp, brine shrimp, blood worms, krill, etc.
  • Keep water level low in the tank to prevent fin nipping by other fish.
  • Turn off any filters or aerators.
  • Remove any rocks, plants, and other decorations in the tank to reduce the risk of injury from sharp edges and underwater currents.
  • Consider adding a second filter on the outside of your aquarium manage the fish that jump out, so the inside walls of the tank do not capture them. (Turn off the filter when you don’t use it).
  • Keep the tank water clean and well oxygenated.
  • Make sure to add good tank mates for molly fish in the tank that have less tempting fins.

If you have tried all these things and it is still occurring, then your best option may be to get a new Molly Fish that will not bite the fins and remove any plants from the tank, which could make identifying who is biting at whom difficult.


In conclusion,  fin nipping is a problem that can affect any aquarium fish. Fin-nippers usually do not hurt the Molly fish. However, it may make them uncomfortable and more vulnerable to other illnesses in their tank or when you transfer them to another tank.

Frequent fin movement on the water’s surface can indicate that another fish attacked your Molly. When you notice a fin nipper, separate the Molly from other fish in your tank and try to find out which one of them is biting them. Then, it will be easier for you to take action without harming any other fish involved in this trouble.

If you’ve ever wondered what Molly Fish Fin Nippers are, this post is for you. We cover all the basics of fin nipping and how to prevent it from happening in your home aquariums with these quick tips.