Fun Electric Blue Jack Dempsey Facts For Kids

Devangana Rathore
Jan 07, 2023 By Devangana Rathore
Originally Published on Aug 05, 2021
Edited by Luca Demetriou
Fact-checked by Abdulqudus Mojeed
Here are some electrifying Electric Blue Jack Dempsey facts! How many of them did you already know?
Age: 3-18
Read time: 8.1 Min

If you are looking for a Cichlid who is a fighter even in an aquarium, we introduce you to Dempsey Jack. Also known as the Electric Blue Jack Dempsey, and goodness, does this fish live up to its namesake's reputation of fighting. Even though a very large tank size is recommended for this bird, this fish is a bred fighter, in a tank and aquarium, and definitely outside of it. Other than its tendency for aggression, the other thing this fish is known for is their electric blue colour that earns them the other half of their name.

Primarily found in the warm, sluggish waters of Central America, this fish has been bred extensively to fill many an aquarium and tank across the world. In fact, they are so common, you can have your own in a tank, and even make them undergo breeding if you so choose. However, if you do that, best be careful, because when breeding, they will not hesitate in hurting others around them. This is why, even though it has a comparatively small size and has easy handling, it is not recommended for beginner tank owners and is best left to those who have experience keeping a tank.

But just because you might not be ready to have these fish in your tank, does not mean you can not read all about them, their favoured temperature, their diet, the plants they like in their tank, their size, and so much more. If you enjoy reading about fish, then check out ladyfish and chum salmon too!

Electric Blue Jack Dempsey Interesting Facts

What type of animal is an Electric Blue Jack Dempsey?

The Electric Blue Jack Dempsey (Rocio Octofasciata) is a type of fish.

What class of animal does an Electric Blue Jack Dempsey belong to?

Electric Blue Jack Dempsey (Rocio Octofasciata) belongs to the fish class in the Animalia kingdom.

How many Electric Blue Jack Dempseys are there in the world?

Due to lack of research, it is not known what the population of the Electric Blue Jack Dempsey fish (Rocio Octofasciata) is. However, since they are bred to be kept in a tank, and their diet in Central America is very fulfilling, they are assumed to have steady numbers.

Where does an Electric Blue Jack Dempsey live?

Some species of the Electric Blue Jack Dempsey fish (Rocio Octofasciata) live inthe ocean. The Electric Blue Jack Dempsey, on the other hand, is mostly a freshwater fish that evolved in the muddy warm waters of Central America.

What is an Electric Blue Jack Dempsey's habitat?

They inhabit bogs and other warm temperature, slow-moving, and swampy waters, living among weedy areas with sandy or muddy bottoms. This species prefer the lowest substrate of these rivers. They enjoy having plants, craters and other structures in their water since it helps them hide and prepare nests for breeding.

Who do Electric Blue Jack Dempsey live with?

Due to their nature as an aggressive, freshwater fish species, the Electric Blue Jack Dempsey (full-grown) (Rocio Octofasciata) can easily live alone. In fact, this species of Cichlids is one of the most aggressive fish you can find in an aquarium or a tank. Since they have a tendency to attack almost every other species of fish, they mostly spend their time (even if they are in an aquarium or tank), alone, fiercely  defending their territory.

How long does an Electric Blue Jack Dempsey live?

The Electric Blue Jack Dempsey lifespan is between 10-15 years, only if the Electric Blue Jack Dempsey baby can survive its early days. This can be difficult in the wild, since their own parent fish can eat them due to lack of food, their small size, and inability to find other food in the wild. The Cichlids species can eventually grow in size with good diet, but until their size is smaller, they will have to stay aware of all other wild species.

How do they reproduce?

Inside their territories, Jack Dempseys lay their eggs on a smooth hard surface, such as rocks, trees, or the glass bottom of either an aquarium or on the river floor in the wild. Like many cichlids, they show substantial care for their fry. Both male and female parents help incubate the eggs and guard the fry when they hatch. Jack Dempseys (Rocio Octofasciata) are known to be attentive and caring parents. They chew food to feed their offspring. However, they have been known to eat their fry when the breeding pair is unable to look after them, or senses something amiss in their environment.

What is their conservation status?

According to the IUCN Red List, their status is "Least Concern." This is possible not only because they are bred for aquarium and tank purposes. They are bred in a specific breeding tank or aquarium, since when they are breeding, they become excessively aggressive, destroying anything around them, including plants, other fish species, Cichlids, and more.

Electric Blue Jack Dempsey Fun facts

What do Electric Blue Jack Dempseys look like?

Electric Blue Jack Dempsey

In appearance, the Dempsey’s head is large, with giant expressive eyes. This coloration, in appearance, looks like it is constantly moving and shifting. They have long, thin fins, an elongated body, and small teeth in their mouth.

How cute are they?

This fish is not cute in the conventional sense of the word due to its odd coloration. However, many have found their blue-green bodies and color fascinating. Many have also said that this color seems to change

How do they communicate?

The Electric Blue Jack Dempsey is a very aggressive fish in behavior and will use its body language to communicate; it may involve nipping at fins, pushing, blowing bubbles, and others. Males will also hurtle though the water, moving their fins and attacking any other species that enter their range. This is mostly seen when the species is protecting its young, feeding, or defending their waters against other wild species (cichlids).

How big is an Electric Blue Jack Dempsey?

The adult Electric Blue Jack Dempsey size is between 8-12 inches, which is almost half the size of the Bala Shark, which grows to a minimum of 15 inches. The Electric Blue Jack Dempsey growth rate is very fast, around a couple of inches every year.

How fast can an Electric Blue Jack Dempsey swim?

Since they prefer the slow-moving water of Central America, the Electric Blue Jack Dempsey is not known to be a fast swimmer. Even in a tank or aquarium, they will not move fast unless their aggressive behavior and territorial temperament is triggered.

How much does an Electric Blue Jack Dempsey weigh?

The Electric Blue Jack Dempseys weighs around 3.5 oz. This corresponds with their size, and this weight can increase depending on what foods they are feed in a tank.  

What are their male and female names of the species?

There is no particular name for the pair of male and female Electric Blue Jack Dempsey (Rocio octofasciata).

What would you call a baby Electric Blue Jack Dempsey?

There is no specific name for the baby Electric Blue Jack Dempsey Cichlid. However, since they grow a couple inches every year, their size should be a fair indicator of their age.

What do they eat?

In short, the Electric Blue Jack Dempsey Cichlid will feed on anything that fits in their mouth, though they prefer shrimp. This includes small fish, too. The Jack Dempsey fish will, however, not eat plants as food, since they are carnivores. Their dietary needs are also dependent on the temperature of the tank, and if they are being given foods to breed them later.

Do humans eat them?

No, humans do not eat the Electric Blue Jack Dempsey Cichlid. This is because they can be prone to disease. A lot of these diseases can get passed on to humans. However, they do keep the Electric Blue Jack Dempsey Cichlid as pets in many an aquarium.

Would they make a good pet?

Though the Electric Blue Jack Dempsey care level is not very high, they should still not be kept by beginners due to their aggressive behavior, territorial temperament, and inability to live with other fish. However, they can handle fairly stable water conditions, with fixed water temperature, nutritious food, and diet, as well as a feeding schedule they can follow. Their water range in aquariums, tank and more, is also extensive.

Did you know...

The males of the Electric Blue Jack Dempsey Cichlid have a larger and also more pointed dorsal fin than that of the female. The male should also have a round black spot in the middle of the body and also at the base of the tail. Females have less spots than males.

Are they aggressive?

Yes, this territorial fish, while not the biggest in the tank or aquariums, can definitely be one of the most territorial around. The Electric Blue Jack Dempsey Cichlid has been frequently known to attack and hurt other fish, and eat the smaller, less aggressive fish in an aquarium.

Having your own Electric Blue Jack Dempsey

The Electric Blue Jack Dempsey price is about 10-15 USD. The Electric Blue Jack Dempsey Cichlid should ideally be stored in a tank with a minimum tank size of 50 gallons. If planning to house a pair or any other species of fish with the Electric Blue Jack Dempsey Cichlid, then the size of the Electric Blue Jack Dempsey tank or aquarium should be twice as big. They should not be kept with tinier or less aggressive fish. Instead, some good options to keep with the Jack Dempsey include the Sand Dollar, Jewel Cichlid, Synodontis, Plecostomus, and more. If you are planning to have them bred, do not keep any other species of fish with them.

In an aquarium, the Electric Blue Jack Dempsey Cichlid diet can be brine shrimp and carnivore pellet. There should also be crater-like structures in their aquarium. This helps them lay eggs, and gives them a place to rest. In addition to this, any plants around the aquarium should also be broad-leafed, thick, and firmly attached, lest the Jack Dempsey fish may attempt to rearrange it. They can handle moderate water hardness, and the water temperature should ideally match their natural habitat.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other fish including yellowfin tuna, or black neon tetra.

You can even occupy yourself at home by drawing one on our Electric Blue Jack Dempsey coloring pages.

Electric Blue Jack Dempsey Facts

What Did They Prey On?

Brine shrimp, yellow shrimp, ocean plankton

What Type of Animal were they?


Average Litter Size?


How Much Did They Weigh?

0.21 lb

What habitat Do they Live In?


Where Do They Live?

central america

How Long Were They?

8 - 12 in

How Tall Were They?








Scientific Name

Rocio octofasciata

What Do They Look Like?

Blue and black

Skin Type


What Are Their Main Threats?


What is their Conservation Status?

Least Concern
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Written by Devangana Rathore

Bachelor of Arts specializing in English Language, Master of Philosophy

Devangana Rathore picture

Devangana RathoreBachelor of Arts specializing in English Language, Master of Philosophy

Devangana is a highly accomplished content writer and a deep thinker with a Master's degree in Philosophy from Trinity College, Dublin. With a wealth of experience in copywriting, she has worked with The Career Coach in Dublin and is constantly looking to enhance her skills through online courses from some of the world's leading universities. Devangana has a strong background in computer science and is also an accomplished editor and social media manager. Her leadership skills were honed during her time as the literacy society president and student president at the University of Delhi.

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