Jack Dempsey fish is considered the most attractive Cichlid species. The best feature is the variety of colors it comes with since no two fish are alike.
They have gained the name from their appearance and ferociousness, which resembles a boxer of the 1920s, Jack Dempsey.
I own a pair of Blue Jack Dempsey cichlid, so I know they can be a nuisance sometimes. But seeing them play every day with one another brings joy to my heart.
Keep reading to know about their habits and how to care for them if you decide to bring one home. I have covered it all, which includes my experience as well.
A Brief Review of the Species
Quick Species Facts | |
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Scientific Name | Rocio octofasciata |
Other Common Names | Jack Dempsey, Mexican Blue Frontosa, Electric Blue |
Family | Cichlidae |
Distribution | North and Central America |
Lifespan | 8 – 10 years |
Max. Length | 25 cm |
Type | Freshwater; Benthopelagic |

Habitat And Origin
These are popular aquatic from the rivers of the Central American region. The Jack Dempsey fish is spread in many parts, including the river of Rio Ulua of Honduras and tributaries like Rio Actopan of Veracruz.
The fish is seen in Belize, Yucatan Peninsula, and even southern Mexico.
They have proven to be an invasive species in the United States of America, Oceania (Australia), and Asia (Thailand). They may have escaped from the local aquariums or perhaps intentionally introduced.
The Jack Dempsey fish prefers temperate conditions of water bodies that are heavily populated with green vegetation. These are freshwater aquatics but pretty comfortable in swamps, murky fields, canals, or irrigated ditches.
How Big Does a Jack Dempsey Fish Get?
They have a fast growth rate and attain a comparatively bigger size than other fishes of the cichlid family. A full-grown adult Jack Dempsey fish size can vary between 8 to 10 inches in the wild.
But in captivity, it is observed that they don’t grow to that length, which is typically between 4 to 6 inches.
Appearance
They have a long, slightly round-shaped body and large flowing fins. The spiny dorsal and anal fins have a reddish line.
Jack Dempsey fish comes predominantly in lustrous shades of blue, green, pinkish-gray, violet, or dull silver body. The glittering sheen can be of various colors.
The body shimmers with bright or dark spots on the smaller sides than the scales. These spots are arranged roughly in a series of patterns.
Note: The color of the fish changes as it matures. So, you will witness stunning presentations in the aquarium that contrasts randomly with the living area.
Stripes may be seen in some specimens, along with a black band extending up to their caudal fin, which may appear darker or lighter depending upon the color of the fish. Their abdomen has a pinkish to whitish-gray hue.
Types of Jack Dempsey Fish
Electric Blue Jack Dempsey
Electric Blue Jack Dempsey is a widespread sub-species, which is slightly shorter in size and less aggressive and territorial than the main species. They grow up to a maximum of 6 – 8 inches.

The fish is named after its striking blue color with black spots over the body and fins. Their dorsal and anal fins have a longer tapered end than the original.
Pink or Electric Pink Jack Dempsey
The Pink Jack Dempsey is another rare breed, which is less aggressive than the original one.

It has the same pattern as the Electric Blue, but instead of the vibrant blue, it is a shade of pink. The spots on their body appear red, and their fins have a bluish hue.
Albino Jack Dempsey
They appear to have a clear and spotless off-white to the light-golden body, while some are also in light pink.

However, these are not true albinos because they don’t have the signature red-colored eyes caused by the albino mutation.
Yellow Jack Dempsey

They look like the regular variety but have a bright golden-yellow body with blue colored spots and fins. A prominent black band stretches from their gills up to the middle portion of the belly.
Average Age
The lifespan of Jack Dempsey fish is about 8 to 10 years in the wild; however, it can live up to 15 years if properly taken care of in captivity.
A good diet, optimal tank conditions, and a disease-free environment ensure a much longer life expectancy for your fish.
But there are also other intrinsic factors, such as genes which could be the bane of its health and is unavoidable.
Gendering Jack Dempsey Fish
Although male and female Jack Dempsey fish have similar appearances, they can be easily distinguished using a few morphological traits when they grow into an adult. A few of them are as follows-
- Males are more extensive in general than females.
- The dorsal and anal fins of the male fish are longer with a pointier end.
- The lips of the male are much more prominent.
- The colors of the female are duller and less vibrant.
- The spot count on the female body is much lower than the male.
- The female fish shows lesser territorial behavior than the male.
Quick Fact: The colors of Jack Dempsey fish get duller when they feel stressed out or sick.
Availability And Price
They are extensively available in both local and online stores. Their price mainly depends upon the shine, colors, and size.
The Jack Dempsey fish on sale can go as low as $15 to even $50 and above. Because of its beauty, many fish-keepers like to put them as showcase fish to attract more visitors.
Care Guide
Quick Care Facts | |
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Care Level | Moderate |
Breeding | Easy |
Social Temperament | Aggressive; Territorial |
Diet | Non-vegetarian |
Hardiness | Moderately hardy |
Feeding Options
Jack Dempsey fish are carnivorous and feed upon small insects, larvae, small crustaceans, worms, and small fishes in the open waters.
You can provide them with high-quality nitrogen-rich fish supplements mainly prepared for cichlids. The living organisms as feed will deliver sufficient protein and other nutrients.
Vegetables help get essential nutrients that the nitrogen-rich diet may not provide. This formulation can be much more nutrient-rich when combined with other meaty foods.
Thus, you can also slip in some green vegetables with the non-vegetarian diet for variations.
A few foods suggestion is listed below-
- Bloodworms
- Brine shrimps
- Crickets and grasshoppers
- Fruit flies
- Planktonic crustaceans
- Meaty food
- Flakes & Pellets
- Lettuce leaves
- Cabbage
- Dandelion leaves
Quick Tip: Feed them twice a day, and the proportion should be enough to be consumed in 2 – 3 minutes by the fish. Follow this measure to make sure they are not overfed.
Temperament And Behaviour
Jack Dempsey fish are vicious and don’t like to share their territory with the same species or other fishes.
It generally chases down the small fish, biting and nipping with the intent to prey. And if two male Jack Dempsey are kept in a tank, they both will fight each other until one is badly injured.
They occupy the middle and mid-lower sections of the tank. So, the topmost and bottom dwellers can live peacefully.
Jack Dempsey fish are not nocturnal and likes to spend most of their time in daylight hours loitering around big holes and dense vegetation. Sometimes also seen digging into the sand to look for food or resting on the base.
Breeding
It is easy to breed Jack Dempsey Cichlid, but you need to maintain specific parameters and setup.
For proper spawning, the parent should be moved to a separate tank. Try to keep the temperature of the water between 82 and 84 °F.
Sometimes it could be hard to find a compatible Jack Dempsey pair but when you do, prepare yourself for a few upcoming weeks.
Author Note: Though being a short-tempered fish, the male rarely shows anguish behavior during the time of breeding.
Mating
Once you are ready with the setup and other necessary conditions, you can induce the pair into the tank.
The male and female will get close and start bumping on the sides like they are trying to push each other away.
The male violently chases the female all over the tank. Sometimes the female may get hurt, so keep an eye out for that.
Spawning
After the female accepts the male as her partner, she then spawns the eggs on a flat surface or a hole in the substrate that the male dug.
The female spawns about 600 – 800 eggs. It’s better to use a large tank, so there is a lot of space for both parents and babies.
Hatching
The spawned eggs get fertilized by the male’s milt, after which both the parents get on guarding duty for the eggs.
The female Jack Dempsey fish looks after the eggs while the male wanders around them to protect them from any potential threat.
The eggs will hatch in 3 – 5 days, depending upon the temperature and incubating period. A dark place is preferred for incubation.
Rearing of Baby
The sac-fry would stay in a hole or a hiding place till they are a few days old. Sometimes you may see the adults feeding on their hatchlings. So, you should either separate the babies or transfer the parents to a different tank.
A good diet for the juveniles may contain Micro worms powered, high-quality dried fish flakes, Brine shrimps (Artemia), or small crustaceans (Daphnia).
Pro Tip: Sometimes, the number of eggs might be too much for the female to look after. So, you can move some of the eggs to a different tank to ease her up.
Pro Tip: Sometimes, the number of eggs might be too much for the female to look after. So, you can move some of the eggs to a different tank to ease her up.
Common Diseases
Jack Dempsey fish are tough and adaptable since they habitually live in the wild, where the waters are murky, making their bodies typically disease resistant.
However, exposure to unhygienic conditions in the tank can eventually lead to health issues if not checked regularly. Using a good filter in the tank and providing a proper diet can help keep the diseases at bay.
Some of the illness issues faced by Jack Dempsey cichlid are discussed below.
- Head and Lateral Line Erosion (HLLE) causes permanent holes or scars on the fish body, so they are named Hole-in-the-Head disease. A cavity develops behind the eye and continues down towards the tail, forming a line along the fish’s body. It is not a life-threatening problem but a sign of bad health conditions of the fish.
- Skin flukes such as Dactylogyrus spp. Gyrodactylus spp. commonly known as flatworms or monogenean trematodes can also affect them. These flukes attach themselves to the body of fish and gills, which can affect their breathing. Treating with antibiotics containing Praziquantel can help get rid of them.
- White spot disease, or Ich, is caused by a protozoan parasite known as Ichthyophthiriusmultifiliis. It is a parasite by itself, having a diameter of 1mm, and is easily detectable by just looking at the fish. These parasites attach to the fish, which appear like tiny white dots all over the body. The Jack Dempsey fish must be immediately transferred to a “hospital” tank and treated with Ich-X or other copper-based medicine.
Tank Recommendations
Quick Tank Facts | |
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Water Temperature | 22°C – 30°C |
Minimum Size | 55 gallons |
Water Hardness | 9 – 20DH |
pH Level | 6.0 – 7.5 |
Nitrate Content | <40 ppm |
Tank Size Requirements
For an enormous fish like Jack Dempsey, you need a big tank. They require a lot of swimming space, or you might see them disturbing other fish.
A tank volume of 208 liters may be sufficient for a junior species. However, an optimal tank size for one fish would ideally be 378 liters.
Setting Up a Tank
Plants
Even though the Jack Dempsey fish is not vegetarian, their digging habits can lead to the uprooting of plants from the substrate. Hence plants with deep roots are more suitable.
A few of them which might be considered a good option are stated below.
- Amazon Sword
- Ludwigia Repens
- Anubias
- Jungle Vallisneria
- Cryptocoryne wendtii
- Dwarf Sagittaria
Putting floating plants in your tank helps to mimic their natural environment. Plants that can be used for this purpose are listed here.
- Water Lettuce
- Hornwort
- Water Sprite
- Frogbit
Lighting
Strong lights will help bring out the shimmer and beautiful colors of your Jack Dempsey fish. Its natural habitat has a dark feel, so they usually hide from the brightness. So, floating plants can help provide shade in lighted aquariums.
You can use regular fluorescent lights or ones that give out a natural daylight color. LEDs can be helpful, but you will require quite a lot of them.
Quick Tip: Halogen lamps might also be taken into account for lighting. They are pretty radiant and can keep the water warm, which suits the fish. Hence, it can also function as a substitute for a water heater.
Substrate
The rivers or swamps where they are naturally found have sand or mud water beds, and such components are easy to arrange as sandy substrates are readily available in most aquarium shops.
The black or red sand substrate is a suitable choice, as it is soft and won’t cause any harm to the fish when they are sifting through them. Tiny fine gravels can also be used as a substrate.
Avoid aragonite sand or ‘cichlid’ sand because they contain essential salts such as calcium carbonate. It increases the pH level and makes the water hard.
Décor
Whatever decoration you decide to use, make sure it is strong and durable. Jack Dempsey fish tend to mess with the decorations and might displace them or even break them.
In the wild, they like to house in small caves or holes in the rocks, where they mark it as their territory. So, putting a few big stones with holes in your tank is a good idea, especially when there is more than one cichlid.
You may also put driftwood or artificial resin logs in the tank, which provides cover and a place to hide.
Tank Apparatus
A powerful filter is a necessity. Most of Jack Dempsey’s diet consists of insects, so they make a lot of mess in the water.
You can even put a heater to keep the water slightly warm above room temperature.
Pro Tip: If possible, use robust, sturdy equipment. And try to keep it out of their reach. They get too curious sometimes and might damage it by biting on them.
Water Parameters
Water parameters are vital keys to good health for any kind of fish. Even if the fish is hardy, terrible water conditions will eventually lead to diseases.

- The Jack Dempsey fish requires tropical or sub-tropical settings in their tank. The water temperature is most suitable between 72 and 86°F.
- The water hardness should be maintained between 9 to 20 dGH.
- Their habitat is slightly acidic in the wild, around 6.5 pH, while the suitable range is 6.0 to 7.5 pH. Adding buffers is an excellent way to maintain the pH of the water.
- They produce a lot of waste because of their eating habit and big size. The nitrate concentration of the water is crucial and should not exceed 40 ppm.
Compatibility With Other Fish
Jack Dempsey fish is quite possessive of its dwelling space and will violently start fighting with any fish that tries to invade it. Thus, it is not advised to put any fish that lingers around their area.
Small aquatics such as tetras, guppies, molly, or nerite snails should be avoided since sooner or later, they will get predated by Jack Dempsey fish.
There are still a few fishes you can choose from which are peaceful and can defend themselves.
- Other Cichlids (Firemouth Cichlids, Mbuna Cichlids, Convict Cichlids)
- Kissing Gouramis
- Clown Loaches
- Plecos
- Silver Dollar
- Acaras
- Angelfish
- Bichir
- Kois
- Green Terror
Frequently Asked Questions
Can we keep two Jack Dempsey fish in a 45-gallon tank?
It will be of no good if you put two Jack Dempsey fish in a 45-gallon tank. The space is too small, and the fish will continue fighting for territory.
Do they have teeth?
Yes, they do have teeth. All Cichlid species have teeth because they are carnivores. It helps them mince and tear chunks off the prey.
Can we put Jack Dempsey Fish with Oscars?
Oscars are peaceful fish of comparatively bigger size than the cichlids.
They are omnivores and will not compete with the Jack Dempsey fish concerning food. Under proper tank conditions, both of them can live together peacefully.
Do Jack Dempsey Cichlids bite humans?
No, they don’t bite intentionally. Jack Dempsey’s teeth are not that big to inflict injury to humans. However, if any situation arrives where you have to put your hand inside the tank to touch them or feed them (not recommended), you must know that their teeth are sharp enough to scrape off your skin and could even cause minor bleeding.
Why does it turn black?
Well, Jack Dempsey fish tends to change colors when it feels unhappy or while facing some sort of discomfort. Changing into black or dark colors signifies some problem with them.
Final Thoughts: Should We Get Them?
Even though Jack Dempsey cichlid is a bit expensive compared to others, the unmatched beauty makes it worth getting for home aquariums.
It is a great fish to have for oneself but caring for them might be a challenge for beginners in the aquarium business.
The good thing is that they can even be kept in a bare-bones tank if you have a small budget. Even a single fish in an empty tank will look good.
So, if you ever decide to buy a Jack Dempsey fish, do not hesitate to get this fantastic fish for yourself or your loved ones.
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