Why Is My Cherry Shrimp Turning Black? (With 5 Solutions)

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When I noticed that my cherry shrimp was turning black, I was terrified. I had a 50-gallon tank, and the shrimp were new, so I didn’t know what to do when it happened. As time passed, I learned that the issue affected most shrimp across the board, and I was able to teach myself how to fix it.

Cherry shrimp tend to become black as they grow. That is primarily manifested in red cherry shrimp that carry genes of black ancestors. Nevertheless, cherry shrimp also blacken when stressed, carry a bacterial infection, or suffer from elevated ammonia concentrations.

As we move forward, I will show you how to distinguish a healthy cherry shrimp that naturally turned black from a sick one. Then, I will share five simple steps to treat cherry shrimp that are actually suffering.

Why Is My Cherry Shrimp Turning Black?

Cherry shrimp can turn black for various reasons. Some of those reasons are innocent. But others are very problematic, so you are expected to investigate such a color change. Some of the potential causes you may encounter during your investigation include:

1. It’s Merely Genetics

You should never discount the effect genetics can have on the appearance of a shrimp. Some cherry shrimp will turn black over time because of a genetic anomaly. This tends to happen randomly. 

You cannot predict it with regards to when it will happen, to which shrimp it will happen, and the nature that the change will take: whether the shrimp will turn black all over or develop spots and patches. At the end of the day, this shouldn’t concern you if your shrimp are healthy and happy.

2. It’s A Matter Of Perception

You have to consider the possibility that your shrimp was black to begin with. A lot of beginners think that cherry shrimp only come in various shades of red. But that couldn’t be further from the truth. First of all, a cherry shrimp’s natural color is green-brown. 

However, selective breeding has allowed aquarists to produce new types of cherry shrimp whose colors vary drastically from their original look. As such, black cherry shrimp are actually quite common.

One example is the Blue Dream shrimp which can come with a completely black body or patches. Another example is the Green Jade shrimp which comes in black as well as red and yellow, not to mention the Black Rose, which is entirely black:

  • Where the color of your Cherry Shrimp is concerned, you have to keep three factors in mind:

First of all, a shrimp’s background can affect your perception of its look. For instance, a tank with light colors will dampen the color of the shrimp, giving the creature a paler look. On the other hand, dark environments enhance the colors of cherry shrimp, making them more vibrant. 

Suppose a tank with light colors at the fish store tricked you into thinking that a dark shrimp had lighter colors. In that case, the dark environment in your home aquarium could push you to conclude that the shrimp has changed colors even though your tank has enhanced its naturally dark colors.

Secondly, if the cherry shrimp is new, it will probably spend a lot of time hiding, especially if you failed to acclimate it properly. In other words, once it finally emerges days or even weeks later, you might falsely assume that one of your older cherry shrimp has turned black. It isn’t always easy to differentiate between new and old shrimp, especially if your tank is overstocked.

Lastly, age is crucial. Many shrimp will change color as they mature. If your cherry shrimp was young when you got it, more than likely, it hadn’t settled into its final color. In other words, the dark colors, be they spots or patches, are a sign that it is finally entering adulthood.

3. Your Cherry Shrimp Is Sick

This is the first consideration most people make, especially beginner aquarists. They think that every new development in their cherry shrimp tank is a sign of illness. Though, in this case, it isn’t a far-fetched assumption because diseases can cause cherry shrimp to change their colors.

The most common is chitinolytic bacterial diseases. Also called rust disease, the condition degrades the shell of the shrimp, causing dark spots and lesions to appear on the creature’s exoskeleton.[1] Caused by chitinolytic bacteria, the consequences of the disease are not restricted to the exoskeleton. The illness will also harm the internal tissue.

It can destroy entire segments of the appendages it has infected. It will also cause deformities in new shells, along with exposing the shrimp to other infections. Professional aquarists expect bacterial infections to change the colors of sick cherry shrimp.

If you have lower grade shrimp that are more translucent (the more opaque the shrimp, the greater the quality), once an infection changes the colors of the internal organs, you may notice the transformation on the outside.[2] 

Fungal infections can also affect the appearance of cherry shrimp. However, of all the conditions that could cause black spots to appear on a cherry shrimp’s body, the most prominent are chitinolytic bacterial diseases. Some people use the term black spot disease.

4. Poor Water Quality

One of the most common causes of a color change in shrimp is poor water quality. Cherry shrimp should be kept in a tank with a pH, temperature, and hardness that fall within a specific range. If you force them to tolerate water outside those ranges, you will observe various side effects, including lethargy, timidity, loss of appetite, and a color change.

While a cherry shrimp is more likely to lose its color when faced with insufficient water quality, it is also more than possible for the creatures to turn black. At the end of the day, you cannot always predict the reaction you will get. 

  • Poor water quality will produce two side effects:

First of all, it will make the shrimp uncomfortable. This will induce stress, which can make shrimp sick, especially if it goes unchecked. Secondly, low water quality will cause the health of the shrimp to deteriorate. It will lower the strength of their immunity, making them more vulnerable to diseases. 

Inappropriate water conditions will also permit bacteria and parasites to thrive, especially if the tank hasn’t been properly maintained. The resulting illnesses will induce stress in the shrimp. The stress will make the shrimp more likely to succumb to the effects of these diseases.

Both of these occurrences, the stress, and the diseases, can cause a shrimp’s color to change. They can also lead to death. But before this happens, you’ll notice signs such as lethargy and loss of appetite.

5. Your Shrimp Actually Died

Shrimp usually turn pink or white when they die. But in some cases, they can take on a blue or black coloration. If your shrimp has turned black, prod it to ensure that it is still alive. If it fails to respond to external stimuli, it is dead.

How To Treat Cherry Shrimp That Turned Black?

You cannot stop your cherry shrimp from turning black if genetics is the cause, and neither can you reverse the process. However, any color changes caused by external factors are pretty easy to resolve, especially if you take the following steps:

1. Improving The Aquarium Conditions

You have to create a healthy environment for your cherry shrimp, especially if they are sick, stressed, or both. They need a temperature of 72 to 78 degrees F and a pH of 7.0 to 7.8.[3] These figures may change depending on the type of cherry shrimp.

They don’t have special lighting requirements. Though, you cannot keep the lights on all the time. Maintain a proper day/night cycle. If the lights are on all day and all night, the stress will send the creatures into hiding.

Speaking of hiding places, do not forget to add live plants to the tank. Artificial plants can also work if you don’t have any other choice. But live plants are better because the shrimp eat the edible matter that the plants shed.

2. Keeping A Clean Tank

You can prevent or eliminate some diseases by simply performing a weekly water change. Though, if the shrimp are sick, you should prioritize smaller water changes of no more than 20 to 30 percent.

At this point, I would highly recommend getting the API FRESHWATER MASTER TEST KIT (link to Amazon). This efficient bundle will accurately measure your pH, ammonia, nitrates, and nitrites. I absolutely love this one because it lasts for hundreds of measures, making it highly cost-effective.

These are the parameters you should aim for when it comes to cherry shrimp:[4]

  • Ammonia and nitrites: 0 ppm.
  • Nitrates: below 20 ppm.
  • pH: 6.2-8.0

If the concentration of toxins like ammonia and chlorine is too high, and your shrimp are turning black, rather than performing a significant water change that may hurt the shrimp, use conditioners that can neutralize the toxins without hurting the shrimp. I personally use the Seachem Prime Conditioner (link to Amazon).

I also suggest installing a sponge filter. It will catch leftovers and other forms of debris. Though, the filter cannot catch everything. You are still expected to remove the dead organisms you find in the tank and any other pollutants that might cause the toxin levels to spike.

3. Picking The Right Tankmates

Give the cherry shrimp friendly and peaceful tankmates that are unlikely to oppress them. That includes snails, corydoras catfish, and small rasboras, to mention but a few.[5] Creatures like dwarf cichlids and silvertip tetras that eat shrimp will induce stress in your cherry shrimp.

If you’d like to create an exciting environment, you can mix cherry shrimp with ghost shrimp, as I explained in this article. The two species can live side by side in harmony. That will reduce the stress your cherry shrimp is potentially suffering from.

4. Dealing With Diseases

You can tackle bacterial infections by cleaning the tank, performing water changes, and asking a vet to recommend a viable antibiotic. With Chitinolytic bacterial diseases, you have to quarantine the shrimp before treating them with Big L’s Pig and Poultry Wormer. 

I also suggest exposing the creatures to 20 or 30-second salt baths. Salt baths can alleviate various infections. I personally do that with the API Aquarium Salt (link to Amazon). All you have to do is pour one tablespoon for every five gallons of water. If that doesn’t work, you should also lower the temperature by a few degrees (Bacteria thrive in high temperatures).

5. Feeding Your Cherry Shrimp Properly

Sick and stressed shrimp require a healthy diet to recover. It can include spinach, carrots, lettuce, algae wafers, flakes, pellets, frozen foods, etc. They can eat the algae in the tank, but you should supplement their diet, especially if they are too weak to forage for food independently.

Why Are My Cherry Shrimp Eggs Black?

Cherry shrimp eggs usually turn black when they have been fertilized. That is typically a sign of a growing fry. Also, the eggs may take on that color if the parents feature black shades. On the other hand, eggs that turn white are usually not fertilized and possibly rotten.

Cherry shrimp eggs may take on a green or yellow color initially, but they will slowly turn black as the shrimp on the inside mature. At this point, you should take extra care to make sure the eggs remain healthy.

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Shrimp that turn black are usually stressed. If that is the case, your cherry shrimp will also manifest signs like loss of appetite and lethargy. Since there is no definitive way to determine the condition’s cause, you should concentrate on providing your shrimp with a healthy and secure habitat. 

You can do that by making sure the temperature, pH, and water parameters are in check. Also, it would help if you didn’t overcrowd the tank. If the stress comes from another source, such as disease, you should tackle the source of the problem while putting your pet in quarantine.


  1. https://aquariumbreeder.com/rust-disease-in-a-shrimp-tank-treatment/
  2. https://aquaticly.com/cherry-shrimp-care-guide/
  3. https://www.aquariumcarebasics.com/freshwater-shrimp/red-cherry-shrimp/
  4. https://modestfish.com/cherry-shrimp/
  5. https://www.tropicalfishcareguides.com/aquarium-fish/cherry-shrimp-tank-mates/