Jack Dempsey Fish- Complete Guide With 5 Important Aquarium Tank Tips!

    Jack Dempsey Fish- Is It the Right One To Go For?

    Jack Dempsey fish is probably the favorite fish of many people out there due to their great personality and bright colors. They are fierce and big fish. But, they are not meant for everybody to keep. Want to know why? Keep scrolling!

    This article covers all the important points of information about jack Dempsey fish so that you can decide if it is right for you nor not.

    Jack Dempsey Fish-Complete Guide

    jack dempsey fish
    Animals Net

    here is an overview to get a brief idea of jack Dempsey fish.

    Care level Intermediate caring needed
    Temperament Aggressive
    Compatibility Does well with other aggressive fishes of small sizes
    Tank set up needs tropical freshwater
    minimum size of the tank 80 gallons
    Family Cichlidae
    Diet carnivorous
    Size 10 to 15 inches
    Lifespan 8 to 10 Years (15 years with utmost care)
    Color Many different colors but Most commonly gray with bright flecks (keeps changing)

    1. Overview

    The scientific name of jack Demsey fish is Rocio Octofasciniata. It is a cichlid native in the streams of fresh water and rivers of Honduras, Guatemala, Belize, and Mexico.

    They are highly popular and populated in Australia, the United States, and some regions of Asia. They are considered to be invasive species in all these areas. They were most likely released here when aquarists released these pets into the wild. They are one of the most popularly known cichlids.

    Although these fishes can be aggressive, that doesn’t mean you cannot keep them in groups with other fishes, those who figure out how to handle them can create an amazing aquarium. But, if you are not able t control their aggression, they might end up harassing other fishes within the tank. When kept nicely, these beautiful fishes introduce ana zing variety and activity in your tank.

    Know that most cichlids belong to American or Africa. They are found in slow-moving water across central America mostly. In Australia and Thailand, they are locally known as Medican Blue Frontosa, a unique name indeed!

    These fishes are carnivorous in nature and live for nearly 8 to 10 years. They may even survive up to 15 years when kept in a great environment with care.

    You may easily get them for 5 dollars to 10 dollars in most aquariums but their price may vary when you go for rare colors and varieties of jack Demsey fish.


    Many people do not go for these fishes as they are put off by their aggressive nature. Those people who have never seen or kept an aggressive fish may struggle quite a bit in keeping a jack Dempsey fish. This is the reason they are not suggested for beginners.

    One interesting feature about jack Dempsey fish is that they do not show an aggressive nature when kept in a tank full of other fishes. This is because they have a difficult time choosing one fish to harass. In such cases, they just mind their own business.

    A male jack Dempsey fish always tried to establish its own territory by fending off other fishes. If your aquarium has plenty of services and caves to form territories, there will be no dispute for territory.

    These fishes spend half of their hiding away in caves because they are quite shy. Mostly you will see a jack Dempsey fish in the lower levels and middle levels of your tank.


    The common name of jack Dempsey fish is based on how they appear. their facial features are pretty strong and have aggressive nature, similar to Jack Demsey, a boxer from the 1920s.

    These fishes have large and oval-shaped bodies with long fins. The male species are larger and hs longer fins. They are highly popular because of their colors. You can get a jack Dempsey fish in many colors and varieties but the most popular variety preferred by people includes Pink, golden, and blue.

    Their colors vary greatly from one fish to another, on the reason behind this is that as they grow old, their colors change. Younger fish usually has a pale gray color with tiny green flecks as they age their color changes to dark purple and gray with bright greenish-blue flecks.

    They may change colors temporarily, usually, they get pale when they are highly stressed while dark when they are mating. You can identify a male or female jack Dempsey fish by looking at their fins. Female has shorter and less pronounced fins whereas males have long anal and dorsal fins with pointed tips.

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    There is another popular variety in blue color known as electric blue jack Dempsey. This variety is mostly preferred because it is less aggressive and slightly smaller than others.

    Your jack Dempsey fish may grow between 10 to 15 inches, but females grow slightly shorter than males.

    Know that a fish cannot reach its full size until you give them large enough space for it. being kept in small-sized tanks messes up with their growth. Know that bigger is always better when it comes to providing a good aquarium for your fish.

    Habitat And Tank Conditions Required

    When present in wild, these fishes live in slow-moving water, mainly freshwater streams. This may comprise swampy areas, canals, lakes, murky rivers, etc. They are mostly used to warm water as they prefer tropical climates for residing. The environment they prefer living in is slightly acidic having low light levels.

    Their surroundings should be sandy with muddy systems, tricks, and debris sitting on the top along with dispersed plants around.

    Tank Setup


    For preparing a tank set up for introducing jack Dempsey fish, start at the bottom of the tank by using a soft and dry substrate because these fishes spend most of their time at the bottom.

    While adding the decorations to the tank, make sure you are adding multiple caves spread all around the tank so that they can hide in them and claim their own territories when other diets are kept.

    You may add some plants too because these fish do not believe In destroying plants. But sometimes they may turn against their wills and destroy the plants for no reason. Make sure you keep checking them so that they do not end up destroying anything.

    jack Dempsey fish will also require a heater for making a temp between 72-86 degrees Fahrenheit. the pH of the water should be between 6 to 7 (slightly acidic) and the hardness of water must be 9 to 20 dGH.

    You do not have to put extra effort into inserting a water pump or air pump because these fishes love slow-moving water only. Just insert nay filter for creating a slight current in the water. This makes them feel more at home.

    Avoid using bright colors as it scares your fish and they end up hiding for long. The water present naturally in the tank should be slightly murky, so try using dim lights. You can also shade certain areas by using floating plants like hornwort.

    Make sure you bring a large water tank instead of a smaller one because you don’t want to provoke their territorial nature and tendencies. They require a nearly 80-gallon tank.

    Each fish requires at least 55 gallons of water but the more the merrier. They appreciate large spaces and more water. You must always keep in mind that these dishes are aggressive and have their own territorial tendencies that need to be fulfilled. They require enough space to hide in the tank.

    Here are few important things to keep in mind while setting their tank up.

    1. Filteration

    Filtration is one of the most important aspects of keeping an aquarium especially for a large fish like jack Dempsey fish. Fish put off waste constantly in the water which surrounds them. The bigger a fish is, the more waste it produces.

    This waste sinks to the bottom of the tank and starts breaking down there putting NH3 or ammonia. Ammonia can be highly toxic for the fishes even when released in a small amount. Fortunately, certain bacteria eat ammonia and convert it into nitrate by a process called the nitrogen cycle. This component is less toxic compared to ammonia.

    You require a good filter to process all the waste as these fishes are large and produce more waste.

    2. Heater

    the heater is a must for keeping jack Dempsey in a suitable environment that feels like home. looking at their natural habitats, you can figure out that they require warmer conditions to survive.

    It is better to use a heater slightly larger than the regular ones for jack Dempsey fish. A small heater struggles to keep the water warm enough for a Jack Dempsey fish. This means you will require the heater to be on for most of the day to keep the temperature warm. This will eventually shorten the lifespan of that heater and you will have to replace the heart now and then.

    You can find a good heater large enough for keeping jack Dempsey fish warm.

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    3. Plants Inside The Tank

    If you are planning to put big and beautiful plants inside your aquarium for decor, then the jack Dempsey fish might not be an ideal fish for you. Like all other cichlids, jack Dempsey fish loves digging the substrates. They might end up riping all the plants you have set up. While some owners do not have any issues and concerns regarding the plants, some owners end up being frustrated.

    Jack Dempsey fish are carnivores, so they will not eat the plant, but they end up dragging to the point where the plants keep floating in the water and require re-arrangement. This will increase your work.

    You can go for floating plants instead like water sprite, hornwort, water lettuce, pennywort, etc. Try not to use rooted plants as they are vulnerable to be attacked by jack Dempsey fish.

    4. Substrates

    For a jack Dempsey fish, gravel or sand are highly recommended substrates. Since these fishes love digging, you cannot risk using plated soil substrate as they will create a mess out of it.

    Also, they look wonderful against dark substrates like gravel. A jack Dempsey fish often change its color to match the surrounding. They turn almost black which makes the iridescent spangles stand out. You can use black or dark brown substrates so that your jack Dempsey fish also darkens.

    Do not go for substrates that are sold using the name “cichlid substrates”. These substrates contain calcium carbonate which will increase the hardness and pH of the water. This substrate might be wonderful for Africa cichlids but jack Dempsey fish cannot thrive under such substrates.

    5. Decor

    A jack Dempsey fish requires a mix of large decorative pieces with pen swimming areas so that they can easily swim and form their territories inside the tank.

    They love having a roomy cave for themselves as he will hide inside it when they feel shy or threatened. Once they acquire their full size, you can insert large pieces of rocks and driftwood to create great hiding spots for your jack Dempsey fish.

    Tank Mates Of The Fish


    The aggressive nature of jack Dempsey fish can be quite restrictive when looking for other tank mates, but this does not imply you cannot add any other species inside. There are some good options to consider.

    Their tankmates generally should be smaller in size than these fishes are should have the same aggressive nature or temperament as these fishes. This means all the fishes should be able to defend themselves without getting into each other’s mouths.

    Peacefulmspecis are usually harassed by all other fishes easily, they might even die livin’ with aggressive fishes. Small fishes such as tetras should not be kept with large fishes as they will be treated as food.

    You can go for oscar fish as it makes a popular option as Mbuna cichlids. Some other choice to consider includes Angelfish, blue acara, bircher, clown roaches, silver dollars, convict cichlids, and fire mouth cichlids.

    Invertebrates like snails and shrimps are also sometimes kept but they are also viewed as snacks only and nothing more.

    Now you might have thought about keeping two jack Dempsey fishes together, right? As a beginner, this is certainly the best option. It is quite difficult to keep any other species alive in the same tank where jack Dempsey fish lives. You may keep two jack Dempsey fish together. But keep in mind that male jack Dempsey fish do not do well with other male species, try to keep one and one female jack Dempsey fish.

    Feeding And Diet

    Being carnivores in nature, the diet of a Jack Dempsey fish normally should include a thing meaty that can fit easily inside the mouth. You may give them small insects, small fishes, crustaceans, and worms to grab easily inside the tank.

    When kept in a home aquarium, there are many options to feed your jack Dempsey fish as they are not picky eaters like us. This makes the work really easy for you.

    You may bring processed dried foods as they are readily available in markets and are cheaper options to go for. You can also find flakes and pellets specially made for cichlids. If you have planned to feed the fish processed food, try to pick some additional live food or frozen food to be added to the tank occasionally. This helps provide the ish with a different range of nutrients.

    Some popular options to consider include brine shrimps and bloodworms. Larger insects can also be given like fruit flies, grasshoppers, and crickets. Know that you cannot give them herbivores food because most probably they will reject the food. This is one reason why the plants you have decorated in the pool remain safe as they’re at low risk of being eaten.

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    If you have an adult jack Dempsey fish, you can feed them 1 to 2 times a day. Try to add only an amount that your fish can finish within 2 minutes. Small fishes or juveniles must be fed 2 to 3 times to enhance their healthy growth.

    Care Guide For Jack Dempsey Fish


    These fishes do not require you to spend your complete day taking care of them. They just need simple caring. The problem of more attention begins when you keep these fishes with other fishes or mix them with different species.

    Handling the aggression of these fishes can turn into a difficult task if you have not handled aggressive cichlids before this. If you are not able o take care of the files properly, they will end up harassing each other and other species of fish respond in the same tank.

    This species does not ake the best option for beginners or newbies at fishkeeping.

    If you can handle jack Dempsey fish due to its aggression, it is really easy to keep the fish healthy. However, they are prone to some diseases like all other freshwater fishes. One of the most common diseases is white spot disease or Ich. This is caused by an ectoparasite that makes white nodules on their fins and body.

    Raising the temp of the water to 86 degrees Fahrenheit may help to prevent this disease. If your fish has already acquired the infection, it can be treated too by raising the temperature.

    Another common disease includes HLLE or head and lateral line erosion. This leads to the formation of cavities or pits on your fish’s head. This disease is caused by improper and pure nutrition. You might not be giving a high-quality diet to the fish. This can be cured by making a useful change to their diet.

    Living in an unhealthy environment also leads to diseases in the jack Dempsey fish. You need to clean their tank regularly. Most of the things you add can end up bringing diseases so make sure it is sanitized and cleaned properly.

    Breeding a Jack Dempsey Fish

    When jack Dempsey fish is ready to mate, their color turns darker. When a pair is ready to mate in the tank, you will easily know by looking at them. Also, when the male jack Dempsey fish is ready to mate but the female counterpart is not, it makes the male aggressive and the female may be harassed by the male to the point of death.

    The condition of the tank also plays a role in mating. Conditions need to be perfect to initiate spawning. make sure the water is entirely cleaned and the temperature mist be nearly 84 degrees. These things make a good trigger to initiate.

    One thing common for cichlids in terms of attraction is their size. Larger males are more successful when it comes to seducing a female jak Dempsey fish. Once mating is completed, nearly 500 eggs are released. These eggs get attached to the tank’s wall, decorations, or any substrate. After completing 3 days, these eggs hatch.

    Jack Dempsey fish are attentive to these eggs and they also dig holes to protect them until they learn to swim. Both males and females share the duty of protecting and guarding a young one.

    jack Dempsey fish even crush the food into small pieces to feed the young ones. They follow these duties until the young ones are big enough to swim and eat on their own. Make sure the parents are not stressed by the tank environment, because if they are, they might end up eating the young one.

    Is It Right To Be Kept In Your Aquarium?

    The design of every aquarium is different. Most of the established aquariums are not good at keeping a whole new group of jack Dempsey fish. These fishes require a separate tank designed especially for them with no other species unless the other species is aggressive like them.

    The main reasons behind a separate tank are their aggressive nature due to which there are many restrictions to the tank mates. They are not very fussy fishes, so setting up their tank is not a hard task.

    They are not very fussy and picky about their diet also, so they will accept most of the food you pour inside the tank. beginners may have some issues and struggle to keep this fish in a good state, but with extra precautions and attention, you will be able to manage these colorful fishes with huge personalities.

    If you are planning to keep a pair of jacks of Dempsey fish, you will have to keep a large aquarium, one with 100 gallons of water or a 378-liter tank.

    If you have gone through all the requirements and you believe you can pride all such conditions for a Jack Dempsey fish, it is highly recommended for you. They’re absolutely gorgeous pets to be kept.


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