Why is my Molly Turning Black? (11 Different Reasons along with easy solutions )
You bring home some pretty Molly fish but after a couple of weeks, it starts to darken in color so naturally you would ask that Why is the color of my molly changing? My mollie’s body has some black patches; is that okay?
We think these are the only inquiries racing through your head when you learn that your molly’s color is changing. But don’t panic; mollies may change their color for a variety of causes, and at one point it is even accepted as normal. However, you must be certain that the change is not taking place as a result of any illness or condition.
Molly fish develop spots and patches of blackness as they get older. But occasionally they lose their color due to stress, excessive ammonia levels, or fin rot infection.

So that everything is understood, we have compiled this material for you guys to read through and comprehend this specific shift in appearance.
Are Molly Fish Color Variable?
Molly fish do indeed change color. In actuality, these fish will alter their colors in response to various circumstances based on their surroundings, gender, and temperament.
For molly fish, it’s crucial to maintain the proper water temperature. When it’s hot outside or they sense danger or anxiety, these fish’s color might become orange. Molly’s greyish-silver tint, which is indicative of the ease with its surroundings, is seen at lower temperatures. This is the time to get a reliable heater for your molly fish.

The ability of Molly Fish to change colors when they want to procreate may surprise many owners. For instance, Molly Fish turn red in color in the females and pinkish-white in the males when they approach each other to reproduce. Females emit pheromones when they desire to mate, which explains why. Additionally, when chasing or battling each other, Molly Fish will alter their color in various patterns.
Male Molly fish will change blue when threatened, whereas female Molly will become dark red to show that it is prepared for a battle.
Finally, Molly’s hues are greatly influenced by the environment. Molly fish has a silver tint when they are living in clean water with healthy ecosystems, but they tend to turn brown or dark orange when they are living in unclean or contaminated water.
When do Molly Fish Change their Color?
Mood and surroundings both influence the color of mollies. For instance, they frequently alter their hues in response to danger or safety. Additionally, these fish exhibit color changes in response to stress, illness, or particular meals like the spiro nucleus. Mollies will change color to show sickness since this diet infects them with a parasite.

When mollies become sexually mature, their color also changes. Additionally, they alter their hue while they are pregnant and during breeding season as a result of higher hormone levels in their bodies. Therefore, the color shift indicates that they are carrying eggs, which darkens their normally brilliant hues.
Related Post: Do Mollies Need a Heater?
Why is my Molly Fish turning black?
Mollies may change color, and this isn’t necessarily a cause for alarm. This modification just affects the appearance of certain mollies, meaning that it has no impact on their health.
This abrupt color shift, nevertheless, signals peril to other fish. Prior to identifying the various reasons, which might include the following, you have no way of knowing how serious the problem is.
1. Genetics (Dalmatian Mollies)
Dalmation Mollies are not black since their birth. At birth, they are white or grey. Their this beautiful color attracts many buyers but as they age, black patches appear on them.
Those shadowy areas might grow over time until the fish is entirely black. Some aquarists are perplexed by this frequent occurrence. Others find it annoying since they bought their dalmatian mollies because they liked the white or grey coloring.

Dalmatian Mollies have a lot of resemblance with the Dalmatian dog that’s why they are named after them.
2. Fin Rot (Black Fins)
Your molly likely has fin rot if the only organs that are becoming black are its fins. This faint color shift can occasionally only be seen until the fins start to tear. The molly’s fins will eventually disappear due to the bacterial infection, which will cause them to get shorter and shorter.

Low water quality, overpopulation, overfeeding, as well as improper handling, are the main causes of fin rot. White spots may occasionally appear on the fins as well, and if your molly has the Ich, they could spread to the body.
3. High Ammonia Levels (Black Patches)
Ammonia level may rise in the aquarium primarily because of not taking care of the aquarium. It may be in the form of over-feeding your fish and the left overs will raise the ammonia level. Moreover, decaying plants in your aquarium may also give rise to the ammonia level. This ammonia rise will result in lowering oxygen level in the water that will badly affect the breathing ability of your molly fish. It will result in the appearance of black patches on the molly skin.
4. Fluke Disease(Black Bumps)
Fluke Disease or commonly called as Black spot disease, is caused by larvae that develop in the intestines of birds. Eventually, the bird’s droppings help the larvae get to the water. Before further development and the transition to fish, they mature and infect snails.
Black patches develop under the fish’s skin when these parasites have settled there. When birds consume sick fish, they become infected with these parasites. Infected snails can spread the black spot illness to your molly fish aquarium.

So, if you have a few snails in your tank, you should be concerned about the Black Spot’s sickness. If the snails are very new to the tank, you could have even more cause for concern. Usually, you’ll see black lumps.
5. Pressure/stress (Black Eyes)
Stress doesn’t result in a reaction as extreme as a change in hue, which is what you wouldn’t anticipate it to. Mollies don’t become black under stress. However, it may have an impact on them and darken their eyes.
6. If They Are Expecting
When mollies are pregnant, their color changes. Particularly in the last days before giving birth, these fish adapt to a brighter orange color to make themselves less noticeable and harder to locate by predators.
7. Whenever They Feel Attracted Towards Other Mollies
When mollies find something appealing, they change color. During the spring and fall mating seasons, these fish often change to a brighter shade of brown to make themselves look more alluring.
8. Ageing Molly Fish
As they age, Molly Fish can develop different colors. As Molly gets older, they often turn a darker shade of brown and lose some of their colors. When kept in captivity, these fish can undergo color changes. While Molly fish maintained as pets may not need to change their colors, fish living in the wild typically need to be more careful of predators.

9. Temperature-related color changes in molly fish
The color of Molly Fish often lightens when the water temperature is too low and darkens when it is warmer. They alter their color in response to temperature to appear more appetizing to predators or to blend in with the gravel and fish tank decor.
10. Mood Changes Cause Molly Fish to Change Color
If they are having mood swings, molly fish can also alter their color. For instance, when they battle with other fish, especially when they start to become territorial, they will become anxious. When under duress, Mollies frequently transform into a different hue to terrify lesser Mollies.
11. Due to Lighting, Molly Fish Changes the Color
Additionally, the aquarium’s lighting can influence how Molly fish seem. In strong sunlight, Molly Fish will turn orange or red; in low light, it will turn darker colors. This is because the illumination causes them to change their hue. Mollies become less apparent and more difficult to observe for predators when they are exposed to excessive light. While fish living in darker environments will seem lighter to better blend in with their surroundings.
The Best Way to Handle Black Mollies
It is impossible to treat a dalmatian molly who has aged-related natural blackening. However, if an outside circumstance led to the alteration in your molly’s color, you can try the following cures
1. Lighting Ammonia Spikes
I suggest performing a water test to confirm if the ammonia level is high. The most effective approach would be to use stripes or testing bundles. I myself use the API Aquarium Test Kit. The API Test Kit takes five minutes to measure the pH, nitrates, nitrites, and ammonia in your aquarium. You also get comprehensive instructions to make your life simpler. Molly fish should be kept in a pH range of 7.5 to 8.5.
If the pH is less than 7.5 or the ammonia level is excessive, you should determine what is causing the elevated concentration, such as overfeeding and insufficient filtering systems, and then take action to reduce it. Along with reducing the pH, you should also make a partial water change.
Replace 15–25 percent of the water weekly to begin with. To get rid of plants and decomposing residues, I also advise cleaning the substrate. Chloramine, a compound made of chlorine and ammonia, should also be tested for. Chloramine is sometimes used to treat tap water.
2. Fin Rot Treatment
Because poor tank conditions commonly lead to fin rot, you should start by doing a water change and making adjustments to the tank’s environment. Once this is accomplished, you can give the fish antibiotics. I advise requesting a useful thing from a veterinarian.

Aquarium salt will be added to the tank to help in the repair process. Make sure to put the ill fish in an isolated tank when doing this. After that, add half a tablespoon of aquarium salt for every gallon of water in the tank.
3. Treatment of the Black Spot Disease
Since snails are frequently the source of black spot disease’s introduction to aquariums, getting rid of the snails would cure any molly fish that has the condition. Black spot illness seldom results in death for its sufferers, making it less deadly than Ich.

Although molly fish may recover from black spots on their own without antibiotics, some individuals choose to take mild antibiotics to treat the illness. You can also think about isolating healthy fish that are parasite-free.
4. Dealing With Stress
Eliminating stress will assist your mollies in overcoming medical disorders that are impacting their coloring, even if they don’t have black eyes. Maintaining a clean tank is the simplest technique to relieve tension in your fish.
Because mollies are tranquil, they should be maintained alongside other calm fish. They require temperatures ranging from 78 to 82 degrees Fahrenheit, a pH of 7.0 to 8.0, and a hardness of 10 to 25 DGH. It would also assist if you grew them in tanks with at least 20 gallons of capacity to avoid overpopulation.
I advise that you always have two to three female molly fish in a tank for every male molly fish due to their passionate breeding behavior. That will stop the men from torturing the women till they pass away. Additionally, it will lessen the rivalry between a girl.
A molly fish is less likely to experience stress if it is housed in a tidy tank with the proper tank mates and environmental conditions, especially if there are lots of plants and decorations for hiding places.
Make sure to add a few, ideally tall ones, if you don’t already have any plants or decorations. Their hiding places should be in the central regions as mollies usually hang out there. Additionally, it would be wise to stay away from aggressive species like betta or angelfish.
What Molly Fish Varieties are there according to Color?
The Poeciliidae family typically includes 40 distinct species of mollies. These fish are available in a wide range of hues and designs. Depending on their surroundings, the seasons, and the mating season, these fish may alter their color. Molly Fish differs in
- Brown Molly (scientific name Poecilia sphenops)
- Citrus Molly (scientific name Poecilia Aurivilliusi)
- Blue Molly (scientific name Poecilia Latipinna)
- Red Molly (scientific name Poecilia Velifera)
- Blue Molly (scientific name Poecilia Glaucocolor)
Frequently Asked Questions
What is a Molly Fish?
Small freshwater tropical fish known as “molly fish” are members of the Poeciliidae family, which also includes guppies, platies, and swordtails. Although Molly fish are originally from Mexico and South America, they have gained international recognition as aquarium pets.
What Does Molly Fish Camouflage Mean?
Mollies use camouflage by changing their color to blend in with their environment. In order to defend themselves against hunters and predators both above and below the water’s surface, they may also utilize camouflage.
Molly fish must blend in with their environment since they are highly territorial. In this manner, it is simpler to spot predators before they notice you. Mollies, therefore, alter their color to fit in with their surroundings.
How Frequently Do Molly Fish Change Color?
Given that Molly fish may change color depending on a number of factors, such as temperature, water quality, and the fish’s mood, this is a difficult question to answer. Mollies can change their color frequently in a single day or only once each week.
These fish typically change color when they are mating. Therefore, it makes natural that Mollies would go through several phases during the season. Mollies may change their color gradually or suddenly, depending on their environment and temperament.
Does a Group of Molly Fish Have Different Colors?
Since molly fish are schooling fish, they frequently congregate in packs. This implies that Mollies in the same tank will essentially change color at the same time. However, Mollies frequently change color at random and for no apparent cause.
Mollies are extremely gregarious creatures. When examining their surroundings, they frequently follow other fish. or if they require assistance with anything. Due to this, the majority of owners think that Mollies may change colors collectively after observing another Molly fish changing hue.
The Bottom Line On Why is my Molly Turning Black?
Checking the kind of your material should be your first course of action if it is going black. If you’re raising a dalmatian molly, its genes are definitely making it darker. As Dalmatian mollies become older, black patches are a natural occurrence.
Though it’s possible that your fish has fin rot if the black spots are mostly in the fins. Black spots, which are also common, cause bumps to appear in the black regions. You must behave in those situations.
Put the ill fish in a different tank, to begin with. Additionally, you want to get rid of any snails that can be parasite carriers. When required, start administering antibiotics to your fish after seeing a veterinarian. Check for ammonia in your water as well. I advise cleaning the tank more regularly if high.