Jack Dempsey Fish: Caring For This Feisty Cichlid

Have you ever seen a fish that looks like it’s constantly angry? Meet the Jack Dempsey fish, a popular cichlid in the aquarium hobby known for its fiery temperament and beautiful appearance.

Despite their tough exterior and feisty behavior, these fish can make great additions to any tank if you provide them with the right care.

In this blog post, we’ll explore the basics of Jack Dempsey fish care – from setting up their ideal tank environment to feeding and maintenance tips – so you can enjoy the company of these fascinating fish in your own home.

Species Summary

The Jack Dempsey cichlid is a popular tropical aquarium fish, and it has been aptly named after the renowned boxer for its fierce attitude and striking facial features. It is a member of the Cichlidae family, which includes angelfish and discus, and is native to Central America, Mexico, Belize, Guatemala, and Honduras.

However, Jack Dempseys have also been spotted in Australia, Thailand, and even the United States, such as Florida, South Dakota, Connecticut, and Hawaii. These sightings are likely due to them escaping from fish farms or being released by aquarists who were unable or unwilling to look after them.

Jack Dempsey’s hardiness and resilience are further demonstrated by their ability to survive in warm temperatures up to 86 degrees. This showcases its moniker’s appropriateness and strength as an aquarium fish.

Appearance And Size


The Jack Dempsey fish is a popular aquarium cichlid known for its large facial features and aggressive behavior, similar to its namesake, the legendary heavyweight boxing champion.

These feisty freshwater fish can range from 10 to 15 inches, with males typically growing larger than females. They have long fins and distinctive muscular bodies, with a characteristic thin body shape that is common among cichlids and other predatory fish.

Jack Dempseys come in a wide range of colors, with the most sought-after shades being blue, green, and turquoise. As the fish ages, its coloration changes, with adult Jack Dempseys having a deep blue background with iridescent scales in blue, green, and even white hues.

The fish’s operculum, or gill cover, is adorned with beautiful patterns, while its lighter blue lips provide a striking visual contrast.

Regardless of the color variation, Jack Dempsey fish are stunning additions to any aquarium, and their hardiness and longevity make them a great choice for experienced aquarists.

The Electric Blue Jack Dempsey

Another popular variety of Jack Dempsey fish is the smaller Electric Blue Jack Dempsey, which features longer fins and an iridescent pale blue color.

However, remember that hybrids may display irregular scales and skull shapes, and the Electric Blue Jack Dempsey tends to be more expensive than regular Jacks. Despite this, it’s still a unique and beautiful fish for any aquarium.

There is disagreement about the origin of the Electric Blue Jack Dempsey, with some arguing that it’s a crossbreed between a standard Jack Dempsey and another species. In contrast, others believe it’s the result of a mutation.

Regardless of its origins, the Electric Blue is more expensive than regular Jacks and can be more challenging to care for due to its more delicate nature. Like other Jack Dempsey, the Electric Blue prefers warm water temperatures of up to 86 °F, and keeping the tank clean is important to prevent disease-causing organisms from breeding.

They also require a carnivorous high-protein diet, and it’s crucial not to overfeed them and cause contamination.

Overall, the Electric Blue Jack Dempsey is a unique and stunning fish that requires proper care and attention to thrive in any aquarium.

General Care Guidelines

Jack Dempsey fish require a specific care regimen to thrive in captivity. These cichlids must be kept in a warm, clean environment with suitable tank mates to prevent disease, stress, and conflict.

A carnivorous, high-protein diet is essential to their health. The natural habitat of Jack Dempsey fish is slow-moving waters, including freshwater lakes, rivers, canals, and swamps. To mimic this, provide a sandy, muddy substrate and hollow decorations for the fish to hide in caves and deep-rooted and floating plants.

The minimum tank size for a single Jack Dempsey fish is 55 gallons, with each additional fish requiring an extra 55 gallons of water. Choosing the appropriate tank mates for Jack Dempsey fish is crucial as they are known to chase, bite, or bully small or vulnerable fish.

Caring for Jack Dempsey fish can be challenging, but with experience and proper care guidelines, they can be a rewarding addition to any aquatic collection.

Recommended Tank And Water Conditions

To ensure a healthy and happy Jack Dempsey fish, they must be provided with suitable tank and water conditions.

A tank size for adult fish is a minimum of 55 gallons is recommended for a single Jack Dempsey fish; each additional fish requires 55 gallons of water. This ensures that all fish have enough space to claim their territories and reduces aggression.

Choose a sandy or muddy substrate that mimics the fish’s natural habitat, and add plenty of caves and hollow decorations for the Jack Dempsey fish to hide in.

The fish’s preferred water conditions include a year-round warm climate with a temperature range of 72°F to 86°F and a pH of 6 to 8. Regarding water hardness, aim for a value of 9-20 dGH.

Jack Dempsey fish are used to slow-moving, slightly acidic, and murky water with low light levels and plenty of vegetation. Deep-rooted and floating plants like Java Fern and Amazon Frogbit are important for providing the fish with hiding places and mimicking their natural environment.

It is crucial to provide a clean environment, suitable tank mates, and a carnivorous, high-protein diet for the Jack Dempsey fish to prevent disease, stress, and aggression.

Keeping these cichlids requires experience and is not recommended for beginner fish keepers. However, with proper care and attention, Jack Dempsey fish can live up to 10 years or more in captivity.

The Ideal Lighting Setup

When lighting your tank, you want it to mimic the natural appearance of deep water.

Although fluorescent lighting is most popular for aquariums, it tends to highlight only the substrate, plastic plants, and ornaments while losing the natural colors of the fish themselves.

Also, over time, fluorescent bulbs dim and must be replaced within months to retain the lighting quality.

Gaining popularity, LED lighting consumes much less energy and lasts for years. In addition, LED lighting creates a more natural-looking tank. Add a floating plant, such as hornwort, if your fish wants shade.

Additional Habitat Recommendations

Jack Dempseys loves to explore the depths of the tank, so you should lay a sandy substrate—such as gravel, grit, or a mix—about 2 inches thick for the tank’s floor.

Fine sand is the best choice for this species because it’s the easiest for them to sift through and hunt. In addition, it has the unique property of settling and leveling itself after the fish disturb it, unlike larger gravel which forms uneven piles and craters.

Providing the Jack Dempseys with lots of caves and hiding places is essential. Driftwood logs, branches, plastic plants, and rocks are good options.

Common Illnesses

Despite the best care, Jack Dempsey Fish can still experience health issues like any other creature.

One such condition is Ich, or white spot disease, which presents as white specks on the fins and body. The tank’s temperature should be raised to 86 °F, degrees to treat infected fish.

Head and lateral line erosion (HLLE) is another common illness that can be brought about by poor nutrition and is characterized by pits or hollows on the head. The diet should be adjusted to a healthier option to alleviate these symptoms.

Jack Dempsey Fish Food & Diet

Jack Dempsey fish require a protein-rich diet to thrive. They feed on a varied diet in the wild, including insects, invertebrates, and small fish. In captivity, they accept most commercial fish foods like pellets, flakes, freeze-dried, and frozen foods.

A balanced diet of protein and vitamins is important for their overall health and coloration. Feeding them small amounts multiple times daily is better than one large feeding.

Providing them with live or frozen foods like bloodworms or brine shrimp can also benefit their health. Additionally, offering them vegetable matter like spirulina flakes can help their digestion.

Overfeeding should be avoided as it can lead to health problems and poor water quality. Keeping a regular feeding schedule and removing any uneaten food promptly will help maintain good water quality in the tank.

With a balanced and varied diet, Jack Dempsey fish can live a long and healthy life in your aquarium.

Behavior & Temperament


Jack Dempsey fish are known for their aggressive behavior and feisty personalities. They are not recommended for beginner fish keepers due to their demanding care needs.

These territorial cichlids will claim areas in the tank, often chasing away smaller and more vulnerable fish. Male Jack Dempsey fish are especially aggressive and will defend their space against intruders.

Providing a spacious tank with plenty of hiding places and decorations is important to minimize aggression. Adding multiple Jack Dempsey fish to the tank can also reduce aggression as the fish will establish their territories.

During the breeding season, their aggression can become more pronounced, and their colors may become darker and bolder.

Despite their temperamental nature, Jack Dempsey fish can be delightful pets. They are active during the daytime, lurking in caves and behind plants. Their bright iridescent colors, ranging from blue, green, and purple, make them a visually stunning addition to any aquarium.

In summary, Jack Dempsey fish require experienced keepers to provide a warm, clean, and spacious environment with suitable tank mates. They are territorial and aggressive, but with proper care, they can thrive and provide years of enjoyment to their owners.

Jack Dempsey Fish Tank Mates

Regarding Jack Dempsey fish, it pays to be extra careful when choosing tank mates.

If you’re a beginner aquarist, your safest bet is to keep them as the only species in the tank. This way, you can avoid any aggression between fish. Furthermore, having just one male in the tank is best, as this will help prevent territorial behavior.

When choosing tank mates for Jack Dempsey fish, it’s best to avoid peaceful species like tetras or invertebrates like freshwater snails and shrimp – unless you want them to become a meal!

Instead, look for fish that are similar in size and have the temperament to stand up for themselves. Popular choices include Firemouth Cichlids, Blue Acara, Angelfish, Plecos, Clown Loaches, Silver Dollars, and Convict Cichlids.


To avoid inbreeding, buying your Jack Dempseys from various breeders at different times is best. When raising four or five together, one pair will likely emerge from the group.

However, be aware that the pair may try to intimidate the other fish, making it necessary to take out the remaining fish before they get hurt.

When attempting to breed Jack Dempseys, pay close attention to their color. This will give you an idea of when they’re ready to mate, as they’ll darken in color and become almost black. If the female isn’t ready for breeding, the male may try to harass her.

You may need to take her out of the tank until she’s ready to spawn, then reintroduce her to the male. If it goes well, they will become mates for life.

A flat stone is an ideal place for spawning. You can watch the pair inspect and clean the stone in preparation for laying eggs – up to 500 at a time! After the female has deposited her eggs, the male will fertilize them. This process is fascinating, even if you’ve bred other fish species.

The eggs will hatch in about three days, and the parents will collect the fry to protect them from predators. About ten days later, the fry will be happily swimming around. Watching the rock-cleaning process is quite adorable, too!


Jack Dempsey fish have become popular for a good reason, but it doesn’t mean they’re the right choice for everyone.

If you prefer a peaceful tank environment and don’t want to deal with aggressive fish, these fish are not suitable for you.

However, we highly recommend getting one if you find their looks appealing. Caring for and keeping Jack Dempseys can be a very rewarding experience!