Jack Dempsey Fish: The Ultimate Care And Breeding Guide

It’s no surprise that the Jack Dempsey fish is one of the most popular and sought after fish in the aquarium hobby.

Also called Rocio octofasciata, these fish are from the Cichlidae family.

This large bodied, aggressive fish has a lot to offer any aquarist: beauty, personality and aggression. But like all pets, they require care and proper housing.

In this blog post I will give you everything you need to know about the Jack Dempsey fish including…

Jack Dempsey Fish Overview

About Jack Dempsey Fish

Origin

Jack Dempsey Fish, like most Cichlids originate in North America, South America and Africa.

They are native to the Amazon River basin in Peru, Brazil and Columbia where they live around areas with vegetation.

This includes flooded grasslands or floodplains where there is lots of cover for them to hide when needed.

They’ve now been established in Australia and Thailand’s warm seas, where they’re referred to locally as the Mexican Blue Frontosa.

Appearance

Similar to the 1920s boxer Jack Dempsey, Jack Dempsey fish have a similar pugnacious look with strong facial features and a large head and body.

This fish has a long, thin form with big fins. Males will be larger and have longer fins. The fin of the male is longer and more pointed than that of the female.

They have an overall tan coloration to them covered in dark spots on the top of their body which become larger near there tail fin area.

The fins are what give this fish it’s name because they display bright yellow colors along them while still having darker ends.

The most popular colors are golds, blues and pinks, and their color will change as they age.

Younger fish start out with a pale green color with green specks. As they become older, their color changes to bright green-blue flecks.

It’s not only age that can change color. They also go a more pale color when they are stressed and mating.

The electric blue Jack Dempsey is a widely grown variety of this species that has become popular since the breed’s original name was “Jack Dempsey.”

This strain is smaller and less aggressive than the standard Jack Dempsey.

Jack Dempsey Fish Size

Male Jack Dempsey fish typically grow to around 10-15 inches, with females being a touch shorter.

Typical Behavior

Jack Dempsey fish are known for being very aggressive and territorial.

They will often fight with others of the same species and kill any fish that could become competition for food or space in their territory.

For this reason, a lot of people are put off, and we would not recommend them to beginners.

They are less aggressive in densely populated tanks because it’s more difficult for them to single out and pick on lone fish.

How Long Do They Live?

Jack Dempsey fish will live for 10-15 years.

The Electric Blue Jack Dempsey

A mutant variety of the regular Jack Dempsey fish.

It still has all of the same needs and general temperament as its more common relatives, but they are less aggressive.

It is interesting to note that they are actually very rare in their natural habitat, which makes them even more sought after by aquarium owners!

They also have some different colors on their body than other types of jack dempsey fish , such as bright yellow spots and stripes along its fins.

The Electric Blue can grow up to 15 inches long while females will only reach around 12-13 inches on average .

They need an aquarium no smaller than 100 gallons so if you’re planning on having one be sure you’ve got plenty of room for them before adding any water since these guys get pretty big and they like

Habitat and Tank Conditions

Tank Setup

The water temperature should be kept between 74°-85° degrees Fahrenheit (23-29 Celsius).

pH levels should range from around 6 to 7 and the hardness level below 100 ppm.

• Temperature: 74°-85°F (23°-29°C)
• Ammonia/Nitrite: 0
• Nitrate: <40 ppm
• pH: 6.0-7.0
• GH: 3-8 dGH (50-133 ppm)
• KH: 4-6 dGH (72-107 ppm)

What Size Aquarium Do They Need?

It’s recommended to provide a 55 gallon tank for a single Dempsey as a bare minimum.

Always go bigger if you can. Bigger is always better such as an 80 gallon tank.

Equipment

Filtration

Filtration is important for any aquarium. Dempsey Fish are big messy eaters that produce a lot of waste.

Some people say to go with bigger filtration, but the right advice is to get enough flow for your tank size.

That means if you have a 55 gallon tank, make sure it’s got an appropriate filter rate (gph) based on the gallons per hour rating for the filter(s).

The best type of filters to use are canister or sump tanks because they provide better water quality and oxygenation without taking up too much room in your living space.

Having proper filtration will reduce nitrates which can build up over time .

It also provides clean healthy water that helps promote breeding behaviors as well as reducing stress levels within fish populations .

Heater

In the wild, Jack Dempsey fish live in the warm waters of South America and Africa, so it is important to emulate these conditions inside of their tank.

It’s always better to go with a bigger heater than you think is necessary because the fish will be more comfortable and less likely to die of shock.

Be sure that your heater is set up away from any sharp rocks or other objects in the tank, as this can damage them over time .

Plants, Substrate and Decor

##Plants

If like myself you are a big fan of lots of aquarium plants, then the Jack Dempsey fish isn’t the species for you.

These fish are known to be very aggressive towards plants, so you will need to avoid any stem plants and particularly anything with long leaves.

You may get some Dempsey fish that are not as destructive, but it’s impossible to tell as each is an individual.

Substrate

As far as substrate goes, you can use fine gravel or sand – whichever one you prefer – but make sure it’s dark colored so it doesn’t show through your fish’s coloring.

It’s also preferable to choose an inert substrate. Avoid using substrates labelled “cichlid sand.”

A planted soil substrate is not a good option for Dempsey’s, since they love to dig and would end up tearing it apart.

Decor

In addition, you’ll need some rocks and/or wood to decorate your aquarium with since these are territorial creatures by nature .

Once they’ve finished growing, large boulders or driftwood fragments that they can hide behind provide excellent hiding places.

Lighting

When it comes to lighting, it’s best to mimic the natural appearance of deep water, and a good choice is LED.

LEDs last significantly longer and use far less energy than incandescent bulbs, making them a smart choice for aquariums. LEDs also produce a more natural-looking aquarium.

Tank Mates

Correctly matching species of fish inside a tank is very important, but as Jack Dempsey fish are extremely aggressive, this can be a difficult task.

You cannot keep jack dempsey fish in the same tank as other species because they will attack and kill them.

The only exceptions to this would be another really aggressive “alpha” type of fish that is larger than your Jack Dempsey, or a much smaller beta-type species that won’t spark any sort of territory aggression from the Jack Dempsey.

Here are some good examples:

• Firemouth Cichlids
• Blue Acara
• Angelfish
• Plecos
• Clown loaches
• Silver Dollars
• Convict Cichlids

Can You Keep Jack Dempsey Fish Together?

For beginners, keeping Jack Dempsey’s in a species-only tank is the best solution. Other species may be difficult to maintain alive.

The best bet is to stick with one male per tank, especially since males don’t get on well with other males.

Common Illnesses

Just like any other species, Jack Dempsey Fish can get common illnesses. But

Knowing the common illnesses can help you get your fish back to health.

The most common illness is called “hole-in-the head” disease which turns into a hole in the face of Jack Dempsey Fish . Other illnesses include ich and fin rot from poor water conditions.

To prevent these diseases from affecting Jack Dempsey’s , make sure to keep good care of their habitat by doing frequent water changes and avoid overcrowding or overfeeding them.

To treat an ill Jack Dempsey , use aquarium salt along with other medications as directed on the package until they become healthy again.

Remember not all treatments work for every situation so consult a professional before making any decisions that could cost your fish its life!

Diet and Feeding

The Jack Dempsey, in the wild, will consume any animal that fits into its mouth, such as tiny fish, worms, insects, and crustaceans.

They Aren’t fussy eaters and will eat, frozen, fresh or live food.

Here are some thing’s foods they will enjoy:

• Bloodworms
• Fresh or frozen shrimp
• Fruit flies
• Brine shrimp
• Crickets
• Grasshoppers

How often should I feed my Jack Dempsey?

One or two times daily is best for adults, whilst young Dempsey will need to be fed two to three times per day.

Any uneaten leftovers should be removed from the tank within a few minutes to prevent decay.

Breeding

Jack Dempseys color will darken when they are ready to mate.

For spawning to begin, the water must be clean and within the parameters mentioned above.

A temperature of 84°F or higher is a reliable trigger.

You should then feed them live food, or you can also simulate the breeding by feeding your fish live worms.

Once they are ready to breed start give them a spawning mop which is either containing java moss, cotton wool or pantyhose tied up in knots with some black thread.

The male will wrap himself around the spawn site and move it so that any eggs laid fall into this area where he fertilizes them. Up to 500 eggs be produced.

At first there may be no activity but after about three days tiny fry will appear everywhere even on plants and gravel.

They grow quickly once born at one-sixteenth of an inch long, often doubling their size every week for the next four months until they reach two inches in length (four cm) at six month old.

Jack Dempsey Fish Conclusion

Jack Dempsey fish are a popular choice due to their interesting characteristics, but may not be the best species for beginners to their extremely aggressive nature.

Remember that that this fish doesn’t pair well with other species, and are best when kept together.

Just remember to keep one male per tank since males do not get along too well.

Do you keep Jack Dempsey Fish? What’s your experience with this species? Let us know in the comments below.