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Electric Blue Jack Dempsey Care: Feeding, Tank Size, and Breeding

The Electric Blue Jack Dempsey proves that there are freshwater fish every bit as stunning as marine reef fish. Standard Jack Dempsies are quite beautiful as well, with bold gold and blue spangles on their flanks. But the Electric Blue Jack Dempsey takes this beauty even further.

Electric Blue Jack Dempsey

They are also full of traditional cichlid personality, digging and strutting around the middle of the tank with supreme confidence. Like many large cichlids they often recognize their owners as well. 

Few freshwater aquarium fish are as much fun to care for. But how easy or difficult is it to raise a full grown Electric Blue Jack Dempsey?

What is the Electric Blue Jack Dempsey?

Jack Dempsies are Central American cichlids. In the wild they are found in Southern Mexico and Honduras alongside other aquarium favorites like Platy fish and Convict Cichlids. Like these fish, Dempsies enjoy hard, alkaline water and somewhat warm conditions.

If you are a history or sports fan then you might recognize the name “Jack Dempsey.” The fish get their name from the legendary boxer. Jack Dempsey was famous for his aggression in the ring. At the time the fish entered the hobby it was one of the meanest you could find – hence the name. 

That said, there are now many other fish in the trade that are much meaner than the Jack Dempsey. They often have names that are just as evocative like the Red Devil, Red Terror, and Wolf Cichlid. Any of these would pick a poor Jack Dempsey to pieces.

The Electric Blue Jack Dempsey is a morph bred for more intense blue color. They also have a bright red eye and long, delicate fins. They aren’t as robust compared to regular Jack Dempsies. But the extra care needed is well worth the effort.

  • Common Name: Electric Blue Jack Dempsey cichlid
  • Scientific Name: Rocio octofasciata
  • Origin: Central America (captive-bred color morph)
  • Length: 6 to 10 inches
  • Aquarium Size: 40 to 55 gallons
  • Temperament: Semi-aggressive
  • Ease of Care: Moderate

Electric Blue Jack Dempsey Care

Caring for an Electric Blue Dempsey cichlid is a little more involved compared to a standard variety Dempsey. But the rewards are worth the effort.

Rocio octofasciata

Electric Blue Jack Dempsey Tank Size

A spacious aquarium is important for these cichlids. A large tank provides more swimming space and maintains water quality by diluting fish waste

As cichlids go, Jack Dempsies are medium sized. Not too large but also not small. I recommend a 40 gallon breeder as the absolute minimum for a single adult or breeding pair of Electric Blue Jack Dempseys. A 55 gallon tank is more comfortable, however. 

Electric Blue Jack Dempsey Max Size

Standard Dempsies will reach 10 or even 12 inches at adult size. But Electric Blue Jack Dempsey cichlid size is a little smaller because they are somewhat inbred. 6 to 8 inches is more common. Sometimes you will see a large male as long as 12 inches but they are quite rare.

Water Conditions for Electric Blue Jack Dempsey Fish

Electric Blue Jack Dempsey fish are a little picky about their water conditions compared to a standard Dempsey. Both prefer neutral to somewhat alkaline water (pH 7.0-7.5). 

Since tap water in most countries is alkaline, you don’t need to make a lot of adjustments.

The problem is that the Jack Dempsey Electric Blue cichlid is more sensitive to elevated nitrogenous waste. Ammonia, nitrite, and nitrate levels need to be watched using a standard aquarium test kit. 

So long as you do water changes and filter maintenance on a normal schedule this shouldn’t be an issue. As carnivores, Jack Dempsies produce a lot of ammonia as waste. And they are large fish – so don’t get lax on water changes.

The preferred water temperature range is 73-78°F; not too warm or cold. Electric Blues are a little disease-prone, often if kept too cold or in dirty conditions. 

If you see ich, fin fungus, anchor worms, or another disease take hold, increase the temperature to 78-82°F. Doing so boosts the metabolism of your fish, helping it fight off an infection

What Do Electric Blue Jack Dempseys Eat?

Jack Dempsey fish are carnivorous and feed on smaller fish, worms, shrimp, tadpoles, and other prey animals. In captivity, the basis of their diet should be high in protein-rich additives. When shopping for fish food, take a moment to read the ingredients label.

Almost all cheap prepared fish foods use corn, wheat, soy, potato starch, and other inferior fillers. These are not healthy for carnivorous cichlids like the Electric Blue Jack Dempsey. Look out for squid, insect protein, fish meal and other animal-based additives.

Pellets are better than flakes because they are much less messy. Cichlids have large mouths. And even a baby Dempsey will eat small sized cichlid pellets as food.

You should also feed live and frozen food sometimes. When young, an Electric Blue Jack Dempsey enjoys blood worms, tubifex worms, brine shrimp, and other invertebrates. For a full grown Electric Blue Jack Dempsey, change over to earthworms, crayfish, and ghost shrimp as treats.

Electric Blue Jack Dempsey Tank Mates

Electric Blue Jack Dempsey Tank Mates

Jack Dempsies are aggressive but not so mean that they have to be kept alone. So long as they have space to form a territory they can be kept with other fish.

In an aquarium smaller than 55 gallons don’t keep them with other cichlids since they will fight. You should add dither fish large enough not to be eaten, however. Silver Dollars, Blue Gouramis, Giant Danios, and Tinfoil Barbs are all good choices.

Other large cichlids are also compatible tank mates. A medium to large cichlid community tank of 75 gallons or more is a wonderful sight. The larger the tank size the better. That way each cichlid has room to form a separate territory and chase rivals out.

Electric Blue Jack Dempsey Breeding

Electric Blue Jack Dempsey breeding is challenging compared to other aquarium fish. You can’t just add a pair of adult Jack Dempsies together – they will fight with each other. 

The best way is to raise a small group of 4 to 6 baby Electric Blue Jack Dempsey fish together. Soon a pair will arise. When you have a pair, you will need to move the others as they will start chasing their tank mates.

Sexing the Electric Blue Jack Dempsey

The sexual characteristics are subtle when they are young. But when they reach breeding size (4 inches) the differences start becoming obvious.

Unlike most cichlids both the male and females are bold colored. Females are always a little chunkier because their ovaries take up space in the body cavity. Males are slimmer and grow larger – up to 50% bigger than a female of the same age. 

A male always has pointed anal and dorsal fins. But be careful as sometimes females have them as well. Males are more aggressive as well. They lip-lock with rivals and flash their fins to welcome any females in the area.


Looking for a freshwater cichlid fish that is as bold looking as any reef aquarium fish? The Electric Blue Jack Dempsey is a great choice. They are more even tempered than a standard Dempsey and tend to stay smaller. 

So long as your aquarium water conditions are good and you don’t mind a little digging you have little to worry about. An Electric Blue will grace a well maintained fish tank for 10 years or more.

More Frequently Asked Questions about Electric Blue Jack Dempseys

I hope you enjoyed this exhaustive resource on a beautiful blue freshwater fish. But maybe you are hesitating before buying a pricier cichlid. If so then here are a few frequently asked questions I get about Electric Blue Jack Dempsey Fish.

How Big Do Electric Blue Jack Dempseys Get?

Electric Blue Jack Dempsey full size tends to be smaller than a standard Jack Dempsey. They are somewhat inbred so they grow slow and not quite as large. The upside of this is that you don’t need as large an aquarium for one. A 40 gallon tank is enough for a breeding pair 8 inches or under in size.

Where Can I Find an Electric Blue Jack Dempsey For Sale?

Electric Blue Jack Dempsies are special fish. Most regular pet stores like Petsmart or Petco don’t carry them. You have to check with an aquarium store and maybe even ask for a special order. Since they are a little pricey aquarium stores buy Blue Electric Jack Dempsey fish on demand.

Can I Keep an Electric Blue Jack Dempsey with African Cichlids?

African cichlids will be good Electric Blue Jack Dempsey tank mates as long as you choose well. Jack Dempsies are territorial but not super aggressive, either. But many Africans, like mbuna, are very aggressive. Choose peaceful to somewhat aggressive species like Peacock Cichlids and Yellow Labidichromis.

Are Electric Blue Jack Dempseys Easy to Keep?

Electric Blue Jack Dempseys are a little more sensitive to water conditions than standard Jack Dempsey. But they are not difficult to care for. As long as your aquarium is cycled and you have a regular maintenance routine your Dempseys should live for years.

Jason Roberts
About Jason Roberts
Jason is an aquarium fanatic that has been a fish hobbyist for almost three decades.