Jack Dempsey Fish: Ultimate Guide (Care, Diet, Breeding & More)

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Written By Matt Stevens

Hi, I'm Matt! I've been obsessed with fishkeeping for over 15 years now and created this site to share my knowledge with others.

The Jack Dempsey Fish are a highly popular freshwater species that are a regular feature in the aquarium community. Having said that, they aren’t the easiest fish to take care of.

Jack Dempsey Fish are known as the fish with an attitude, and their care is something that beginners will have trouble in doing properly.

However, there is no cause for concern, since this helpful guide is designed to help you learn all about caring for the Jack Dempsey Fish, including their habitat, water requirements, diet, breeding, tank mates, and much more!

Species Overview

The Jack Dempsey Fish is named after the American professional boxer William Harrison Dempsey, who spent the greater part of his career as the world heavyweight champion. The fish is known to resemble the boxer, both in temperament and appearance.

Jack Dempsey Fish are members of the Cichlidae family, and they have the scientific name Rocio octofasciata. They are native to the tropical waters of Central America, including Mexico, Honduras, Guatemala, Belize, and several other countries.

Life SpanUp to 15 Years
Color FormGray body with bright flecks
Care levelIntermediate
CompatibilitySimilar sized aggressive fish
Size10 to 15 Inches
Tank SetupTropical freshwater
Minimum Tank Size80 Gallons

Apart from their natural habitats, Jack Dempsey Fish can also be found in Australia and Thailand. Plus, they are also found in Connecticut, Florida, Hawaii, and South Dakota.

The occurrence is due to the fish escaping fish farms in these locations, or being let go by aquarium owners who find them difficult to take care of.

Jack Dempsey Fish are known to be quite hardy and resilient, as they can easily live in high water temperatures. They have a striking appearance and large facial features as well.


You will be delighted to know that Jack Dempsey Fish have the potential to be your long-term pet, as they can live anywhere between 10 to 15 years.

Since they are quite hardy and known to survive in different water conditions, you just have to take good care of them to prolong their lifespan.

However, this also means that owning and raising Jack Dempsey Fish is a long-term commitment, for which you need to be mentally prepared. If you can’t take out time from your busy routine for their care, then you may have to reconsider keeping them.


The Jack Dempsey Fish is named after the renowned professional boxer because its facial features closely resemble those of him.

Both the male and female Jack Dempsey Fish feature a large and oval body that looks quite muscular when compared to other fish. They also have long fins, and the males with brighter bodies have larger bodies and longer fins with pointed tips.

The appearance of the Jack Dempsey Fish is similar to other fish of the cichlids family, which are characteristically aggressive and predatory.

Another reason for the Jack Dempsey Fish’s popularity is that they come in a variety of bright colors. Some of the most attractive fish are colored in shades of blue, pink, and gold.

However, Jack Dempsey Fish start off with pale gray or tan bodies, which are adorned with several distinguishable vertical stripes.

As the fish mature, the stripes start to fade and they change colors, but the hints of blue and green colors still remain on some of their scales. Their operculum is also decked out in the same pattern.

Another striking feature of their appearance is their lightly colored lips, which provide a perfect contrast to their bodies.

Types of Jack Dempsey Fish

There aren’t many varieties of the Jack Dempsey Fish, except the Electric Blue Jack Dempsey. Not only do they have a striking electric blue-colored body with black spots on them, but they are much less aggressive than their counterparts.

The Electric Blue Jack Dempsey Fish are a type of hybrid fish and have a different skull shape than the standard Jack Dempsey. Plus, they also have irregular scales.

Most experts suggest that this type of fish is a cross between a Jack Dempsey Fish and another cichlid, whereas others believe that it is the result of a mutation.


Jack Dempsey Fish are on the larger side when it comes to fish sizes. In their natural habitat, the males can grow up to 12 inches, whereas the females can top out at 10 inches.

However, when they are raised in an aquarium, the males will grow out to 10 inches and the females grow up to 8 inches.

Since Jack Dempsey Fish can be quite muscular and long, you need to put them in a larger tank as compared to other fish. Not only will it help them grow to their full size, but also keep them healthy and happy.

Another thing you need to consider is that the Jack Dempsey Fish expel a lot of waste due to their thick bodies. This warrants the need for a larger tank, as well as a suitable filtration system.

Jack Dempsey Fish Care

If you want to raise and breed Jack Dempsey Fish in your home aquarium, you will have to consider and learn a lot of things before you are fully ready.

Generally, their care requirements and instructions are fairly easy to understand and follow, since they are hardy fish. As long as you don’t overcrowd the tank with too many Jack Dempsey, you are good to go.

However, the more challenging part is to handle the aggression of these fish, which is why it is believed that the more experienced aquarists should raise them.

You also have to remember that since their lifespan is quite long, you have to maintain their care regimen strictly in order to avoid any diseases.

Tank Size

When you are planning on keeping Jack Dempsey Fish, your existing aquarium probably won’t be sufficient. This is because they require a minimum tank size of 55 gallons to live peacefully. Since they have an aggressive and territorial temperament, you need to give the fish their space.

Moreover, if you are looking to place two or three Jack Dempsey Fish in a single tank, then you need to ensure that it has a capacity of at least 150 gallons. Otherwise, they may start fighting with each other just to claim control over their territory.

Even if you buy a little Jack Dempsey Fish, you have to be prepared for the fact that they will grow to their full size. Therefore, if you are keeping them in a small tank, you will have to move them as they start to grow.

Water Parameters

When it comes to caring for Jack Dempsey fish, you have to maintain the water quality most of all. Poor water quality or sudden changes in the water temperature can be dangerous for their health.

First of all, the water temperature should be set at 72-86°F, and you can periodically monitor the temperature by keeping a water thermometer with you.

Apart from this, the pH level of the water is also of great importance. Jack Dempsey Fish are used to acidic environments in their natural habitat, so you should aim to keep the pH level between 6 and 8.

Last but not least, water hardness is another key factor you need to consider. The water hardness should be between 9 and 20 dGH.

Moreover, you should also ensure that there is no ammonia or nitrate in your fish tank, as they can put a lot of stress on your Jack Dempsey Fish.

If these are even found in a little or moderate amount, they will weaken their immune systems and they will be prone to disease and parasitic infections.

Jack Dempsey Fish are used to slow-moving waters, so you can make do without a water or air pump inside the tank. However, a filtration system is of utmost importance, since these fish produce a lot of waste.

You can choose between different types of water filters, such as canister filters, hang-on-back power filters, and several others. Ideally, you should get a larger filter to clean out all the waste proactively from the tank.

What to Put in Their Tank?

Jack Dempsey Fish usually swim around the lower and middle levels of the aquarium, which is why a sandy substrate would work best for them. You can use gravel and grit to form a substrate mixture and layer it 2 inches deep on the floor of the tank.

Like other cichlids, Jack Dempsey Fish are also used to having sand in their mouth while scavenging for food, so a soft and sandy substrate keeps them safe from getting their skin injured while sifting through the bottom.

Even after the fish hunt for their food, the sand will settle evenly at the bottom of the aquarium. If you use pebbles or larger gravel, it would result in an uneven layer.

Apart from this, you should also consider setting up hiding places for these fish, and caves are also ideal for them to claim their territory. You can also add rocks, artificial plants, branches, and driftwood for them to hide in.

Live plants are also suitable for the tank, and you can add java moss and Anubias to create a natural environment for the fish.

Lighting is another thing you will need to take care of when you are raising Jack Dempsey Fish in your home aquarium. Since they are used to deep water, you can use LED lighting to emulate that effect. Although fluorescent lighting is much more common, it doesn’t provide the right effect to create a natural environment for Jack Dempsey Fish.

LED lighting is much more durable and consumes a lower amount of energy, so you won’t even have to worry about the electricity costs.

Common Diseases

You may give your Jack Dempsey Fish the best care possible, but they may still have a chance of getting ill. This doesn’t mean that they are weaker than other species of fish, or are more prone to disease.

With your busy routine, it can be difficult to monitor the water quality and tank conditions regularly, which may lead to the fish getting infected.

One common disease that these fish are infected with is called Ich, which mostly happens to tropical fish. Ich is short for Ichthyophthirius multifiliis, a ciliated protozoan that causes this disease.

Since Ich causes white spots to form all over the fish’s body, it is also called white spot disease. Fish suffering from it tend to scratch their bodies against caves and other objects in the tank, and may also exhibit unusual behavior.

Plus, they might also stop eating properly, while also spending excessive time in their hiding spots. Although they can easily recover from it and also develop immunity, some fish are affected severely by it. The infection affects their tissues and may also cause them to die.

If you want to treat your Jack Dempsey Fish, you can add aquarium salt to the tank. To avoid it from happening in the first place, you will have to be wary of the tank conditions and water quality, especially the temperature.

Apart from this, a healthy and well-balanced diet also keeps the Jack Dempsey Fish free from diseases.

What Do Jack Dempsey Fish Eat?

To ensure that your Jack Dempsey Fish are healthy and also grow properly, you have to take care of their diet as well.

Since Jack Dempsey Fish are carnivores, they are used to preying on any animal that is smaller than them in the wild. These include small fish, insects, worms, among others.

Thankfully, Jack Dempsey aren’t fussy about the food they eat, so you can feed them a variety of living, fresh, and frozen foods.

If you want a fuss-free approach to their diet, you can give them dried pellets and flakes that are easily available in the market. Even if the food floats on the surface of the water, the Jack Dempsey Fish will come up to eat it.

However, you shouldn’t rely solely on processed foods and should mix things up with live and frozen foods every now and then. This ensures that your fish are getting their required nutrients as well.

Some of the fresh and live foods that you should feed them are bloodworms, brine shrimp, fruit flies, fresh or frozen shrimp, crickets, and several others.

Adult Jack Dempsey need to be fed twice a day, whereas the young ones need two or three feedings as they need more nutrition to grow. Make sure to put enough food that they can eat, otherwise, the leftover food starts to rot and contaminate the tank.

Behavior & Temperament

The sole reason why Jack Dempsey Fish are named after a legendary boxer is because they have an aggressive temperament, which is something boxers are known to exhibit in the ring.

Due to their behavior, Jack Dempsey Fish are best treated and taken care of by experienced aquarists.

The male species have territorial instincts and they don’t like anyone invading their space, so you should put a sufficient amount of caves and hiding places for them to mark their territory.

Jack Dempsey Fish Tank Mates

Due to their temperament, Jack Dempsey Fish are quite picky about who they cohabitate with in an aquarium. Ideally, you should keep them alone in a tank so that you can work around their aggression.

Moreover, you shouldn’t place more than one male fish in the tank, or you might invite trouble. Plus, since they are used to eating smaller creatures, make sure you don’t put any of them in the tank.

The ideal tank mates for Jack Dempsey Fish are larger and aggressive fish, which include:


Jack Dempsey Fish are quite easy to breed, and they tend to breed in pairs only. Therefore, you should isolate them from the group, otherwise, they might scare away the other fish.

When the fish are ready to breed, their color will start to darken. You may have to remove the female fish from the breeding tank until she is ready to spawn.

A Jack Dempsey pair requires a flat stone to mate. They will inspect and clean it before they can start to spawn. Once the process is complete, the female will lay as many as 500 eggs on the stone. Then, the male will fertilize them.

The eggs will begin to hatch within 72 hours, and the fry are placed into pits dug into the substrate by their parents. This is done to protect them from other Jack Dempsey Fish. Within 10 days, the fry will have grown enough to swim around freely.

Final Thoughts

By now, you should have an idea of how aggressive and territorial Jack Dempsey Fish can get, and their care requires an intermediate level of knowledge and experience.

However, this doesn’t mean that you shouldn’t consider keeping them as pets.

If you aren’t fond of aggressive fish, then the Jack Dempsey might not be for you. However, if you follow the care instructions that we have outlined in this guide, you will eventually be able to make their care a part of your daily routine and enjoy this creature!