How big do Jack Dempsey fish get? (2023)


#jackdempseycichlid #cichlids #aggressivecichlid #fishkeepingjamaica

This video highlight my sunday adventure in my Jack Dempsey pond.It was a humongous task.
Jeremy Gay profiles one of his favourite cichlids that's named after a boxing legend, but insists it's now more of a pacifist than pugilist when compared to more modern bruisers.

Get someone to draw a cichlid, or simply describe one, and he or she will probably get close to a Jack Dempsey: large, thick-set, big eater and too boisterous and predatory for the average community tank.

Jack Dempseys are archetypal cichlids popular for so long that their namesake, the famed American heavyweight boxing champion of the world, William "Jack Dempsey" Harrison, had his heyday in the 1920s!

Dempsey remains ranked number seven in the Top 100 greatest punchers of all time and for fishkeeping pioneers this Central American cichlid must have had many similarities. However, compared to some cichlids now commonly available, the Jack Dempsey has dropped down the rankings and is kept now more for its colour than ferocious behaviour.


The Jack Dempsey naturally occurs in Mexico, Honduras, Guatemala and Belize, although it has been introduced — or escaped — to other areas with year-round warm climates. It naturally inhabits warm, sluggish waters, feeding on worms, crustaceans, insects and fish.

It’s quoted up to a maximum 25cm/10”, although I’ve never seen adults that size. Much more realistic is 20cm/8”, with females less than 15cm/6”.

Like many cichlids the Jack Dempsey has an interesting past; starting off as Cichlasoma biocellatum more than 100 years ago, then changing to Cichlasoma octofasciatum, Heros octofaciatus, Parapetenia octofasciata, Nandopsis octofasciata, Archocentrus octofasciatus and most recently Rocio octofasciata. However, despite these many changes, the species will rarely be mistaken for anything else. I’ve kept them many times because ‘JDs’ are hardy, easy to keep, easy to breed, colourful, cheap to buy and improve with age.

They are also a tough, quite boisterous fish, yet not massive in size — meaning that for most, if not all, of their lives they could be housed in a 120cm/4’, or ideally 150cm/5’ tank.

I’m not recommending a 180 x 60 x 60cm/6 x 2 x 2’ tank as a minimum, as I would for other Centrals like a Midas cichlid. Although more boisterous than your average fish, they are certainly not one-fish-one-tank creatures, so can be housed with other large, hardy species.

Part of what has made JDs so popular is their ease of keeping. In nature their waters are generally hard and alkaline, pH 7-8, with a temperature range from 22-30°C/72-86°C, depending on time of year. That encompasses a large bracket of tolerable water conditions, matching how most of us keep our tropical tanks — and if your pH were to go higher or lower, that’s fine too.

A 240 l/ 53 gal tank with external filter would be a good start for some juveniles. Jack Dempseys like to mouth the substrate looking for food and will dig when breeding, so provide a substrate some 5cm/2” deep of sand, grit or gravel, or a mix of types and grain sizes.

I prefer the natural look, so decorate with large pieces of bogwood and large rocks, placing the rocks first so if the fish do dig, you won’t get rockfalls.

Jack Dempseys are middle to bottom dwellers and territorial, so place décor to carve up the tank bottom into clear territories, but also provide vertical structures or plastic plants to break lines of sight.

You could use tough live plants like Java fern or Anubias on wood or rocks, although when I keep JDs the fish do their own aquascaping when growing.



Hi everybody welcome to another episode of which keep in Jamaica welcome to my channel to be a, you know, humongous task on a niche I, honestly, don't like I.

Am gonna have to empty the spawn and take out the fish I, just put something there on one side and also look for the babies and place them in anything and it's going to be our media really difficult to ask how it might be in the entire be so I'm, first thing, I'm gonna do I'm gonna have to get a container to put the something.

So after taking all the plants, no big Commission.

This might take a little bit this one overgrown vegetation, unethical so I placed in a context.

Upon this video might end up being in several parts because just makes our work and I want you to be right there? What is dark in color from above Rimmel? Because it is so conditioned as the pond is so conditioned besides on there and the base of the pan it's covered with algae.

And in some cases, yes and even contending with the ants on the floor, some point I'm gonna have to be in the pond to search for the fish because they're not gonna say, hey, Here, I am take me out magic task.

Because of the amount of fish we're gonna be difficult for me to find a Dempsey, especially the babies why because little to hide hide whenever I have service in the box.

The hands have already started several cinder blocks in it along with along with one more fish in and I.

Move them to my son, the backward, then I've been clicking the based on volume of few strategies in the pot, I'll be separating and moving I'm, not sure if I'm gonna be selling I'm.

So attached Kaminski I'm, not sure if I'm gonna be selling into the pet shop and it's working on my foot, very very, very very so I.

Am in the pan I'm trying to get these fish out so that I can cream.

Alright, there are several babies in it.

So I have to be mindful, not to let it down too long because I do not want my phone to burn off so I strategy in which I catch them.

What happen is that they love to hide in the pipes, but it's chained them.

So it's another pipe.

Oh, so this is one of my dempsey have about Puppy Bowl 50 item in here, plus a spawn, I have the task of actually searching for them in the mud, the field to get in periodical or tell do I actually check to see if I have any babies.

But the babies would have ended up going into a different a different container.

So I have several pipes there.

And when I'm finished taking up all the Python to ensure that all the fish are absolutely taken out, I will go to the more than the field ensuring that none of them are near I mean, I'm sure all of them are out then I, just stick of the pipe is one of the fun.

Haze of me, actually getting them I do not want too much of them in one point, one time, but I know that they will be hostile to each other.

You can see the home promenade on this.

One it's, really big.

Alright, I'm gonna break a little bit now I'm place it into the aquarium.

Oh I'm gonna be placing I'm gonna be placing some of the pipes in the water with intention that some of these fish will actually go back into the pipe.

So I can actually catch them and remove them from the pan I want to put the motor in today right because this system in it.

I mean, I'll give you up the side love.

It bear in mind I have about 49 adults because I have about two spawns in the pond right? So so far.

These are my chances right, very big, very active.

And they are developing nicely.

Let's continue to clean my pond.


How big do Jack Dempsey fish get? ›

Size: Perch-like in shape, the Cichlasoma octofasciatum is a large cichlid, reaching seven to eight inches (18-20 cm). Behavior: Its common name refers to the boxer, Jack Dempsey, because of its fighting demeanor. They are extremely aggressive and excitable; schools are formed only when young.

What size tank does a Jack Dempsey need? ›

For a single fish, I would recommend a 55 gallon (208 liter) tank as the absolute bare minimum. Bigger is always better when it comes to aquariums, especially when you're housing large fish. If you want to keep a pair of Dempseys, a 100 gallon (378 liter) tank would house them nicely.

How long does a Jack Dempsey fish live? ›

The Jack Dempsey cichlid fish has an average lifespan of 10 years in the home aquarium, but giving it quality care and a healthy environment can extend its life expectancy to 15 years. This fish reaches a length of up to 12 inches and should be kept in groups of six or more fish.

How fast do Jack Dempseys grow? ›

Q: How fast is the jack dempsey cichlid's growth rate? A: We have done a couple of researches in different online forums, most respondents say that Jack dempseys grow relatively slow. A three-year-old spans 9 inches, and 21 month old spans about 7 inches.

How big do Jack Dempseys get in captivity? ›

Jack Dempseys fish characteristic

They reach 10-15 inches in length. However, in captivity, they grow only to about half this length. Male Jack Dempsey fish tend to be bigger (8 inches) than females (six inches). The average lifespan of the Jack Dempsey fish is from 8 to 10 years.

Can I put a Jack Dempsey with an Oscar? ›

Jack Dempseys can be kept with Oscars thanks to their twin aggression, but it is important that there be more than one fish in the tank to avoid bullying, along with plenty of space. Pros of keeping with Oscar: Large enough to avoid being eaten or bullied.

What temperature do Jack Dempseys like? ›

The Jack Dempsey natively lives in a tropical climate and prefers water with a pH of 6-7, a water hardness of 9–20 dGH, and a temperature range of 22–30 °C (72–86 °F).

What food do Jack Dempseys eat? ›

Jack Dempsey fish are primarily carnivorous. Their diet consists of anything that can go into their tiny mouths, including worms, insects, crustaceans, mollusks, crayfish, algae, small aerial insects, and even small fish.

Are Jack Dempseys hardy? ›

These fish are hardy and relatively easy to look after, making them a good option for a beginner, although the Jack Dempsey is not suitable for life in a community aquarium.

How aggressive are Jack Dempsey cichlids? ›

They are extremely aggressive and excitable; schools are formed only when young. Diet: They are omnivorous, feeding on worms, crustaceans, insects, fish and plants. Reproduction: These open spawners are highly aggressive during the spawning period.

What is the easiest fish to grow? ›

Some of the easiest fish to take care of include white cloud minnows, cherry barbs, goldfish, guppies, neon tetras, and cory catfish. All of these species are relatively peaceful, non-demanding fish that do well in a beginning fish tank.

Why do Jack Dempseys change color? ›

Feeling Low. Not unlike human beings, fish experience both highs and lows in their spirits. If a Jack Dempsey cichlid's coloration abruptly and seemingly out of nowhere turns paler, it could be a sign of a fish who is unhappy or irked about something.

Are electric blue Jack Dempsey rare? ›

Though the Blue Dempsey is relatively easy to breed, it does take a considerable amount of time, luck, and a well designed aquarium set up, so these fish are rather rare and quite a bit more expensive than many other tropical fish, include the Electric Blue Jack Dempsey's progentitor species, the Jack Dempsey.

How big of a tank do you need for 2 Oscars? ›

Because Oscars typically grow about 10 inches long in captivity, the minimum tank size recommended for a single Oscar is about 55 gallons. Ideally, however, a 75-gallon tank is best for one adult Oscar and, if you plan to keep more than one, you will need a tank at least 100 gallons in capacity.

How big do firemouth cichlids get? ›

The male firemouth cichlid stays relatively small and will only grow to about 6-7 inches (15.2-17.8 cm) with females only reaching 4-5 inches (10.2-12.7 cm). With proper cichlid care, these fish can easily live to be 10-15 years old, though it is much more common to see shorter lifespans despite excellent care.

How big do Jaguar cichlids get? ›

Size: Adults are usually found to be between 16 to 24 inches (41-61 cm) and weigh up to approximately 3.5 pounds (1.6 kg), with males being larger than females. Behavior: A beautiful, but extremely aggressive, territorial and predatory species. Diet: Their diet is small fish and invertebrates.

What fish should not be in a planted tank? ›

Avoid species of highly herbivorous fish that will eat your aquatic plants like goldfish, the Buenos Aires Tetra, and Silver Dollars. Some larger Cichlids and Plecostomus (such as the Common Pleco) may also want to be avoided, as they have a tendency to “redecorate” or push plants out of place.

How many cichlids can I put in a 55 gallon tank? ›

55 gallon African cichlid tank: Anything between 15 – 32 African cichlids. 75 gallon African cichlid tank: Anything between 15 – 42 African cichlids. 125 gallon African cichlid tank: Anything between 40 – 72 African cichlids.

How big do electric blue Jack Dempseys get? ›

Origin: Atlantic coastal Mexico and Central America. Average adult size: Up to 8 inches (20 cm) Average purchase size: 1+ inch (2.5 cm)

What do you feed a baby Jack Dempsey? ›

It's best to feed the fry infusoria for the first 48 hours, and then move them onto either baby brine shrimp or microworms. Commercial fry food can also be used for the fry. As with many other new cichlid parents, Jack Dempseys may consume their first few broods.

Can Jack Dempseys live in cold water? ›

Due to the pool's small size, the Jack Dempsey Cichlid fish has often been subjected to eradication. The appropriate temperature for this fish is 11 to 30 °C. However, they can also survive in cold temperatures between 8-10 °C. It is advisable not to keep them in high salinated water.

Do Jack Dempsey eat other fish? ›

In the wild, the carnivorous Jack Dempsey will consume any animal that fits in its mouth, including small fish, worms, insects and crustaceans. Because they aren't fussy, you can feed them prepared, frozen, fresh or live food.

How often do Jack Dempseys lay eggs? ›

It takes hatchlings about four to six weeks to be independent, at which point the parents can breed again. It's possible to have a new fry of Jack Dempseys every four to six weeks. Jack Dempseys are very predictable when it comes to breeding, so it's easy to predict when they are going to lay eggs.

Do Jack Dempsey fish have teeth? ›

Jack Dempsey cichlids do have teeth. As a carnivore, the teeth are very useful in consuming meat. Raising these fishes as pets is not recommended to beginners. However, when they are put inside well-populated aquariums, they become less aggressive than in the wild.

Do cichlids like heavily planted tanks? ›

The large cichlids from Africa are not really suitable for a planted aquarium, though. Plants are sparse in their natural habitats, and in the aquarium the fish basically consider them food. Only hard-leaved aquarium plants such as Anubias stand a chance of surviving.

What is the largest freshwater cichlid? ›

Some species grow to only 4 cm (2 in.), but the largest cichlid, Boulengerochromis microlepis, can reach a size up to 90 cm (3 ft).

What is the most intelligent cichlid? ›

Tiger Oscar Fish

The Tiger Oscar is an African cichlid and is known to be a highly intelligent fish in the aquarium hobby. Oscars are fondly known by their owners as “water dogs” because they are interactive fish that act with purpose.

What is the most trainable fish? ›

Goldfish, betta fish, and clownfish are all interactive and active fishes that enjoy being around people. They are known to be curious and can be trained to do tricks.

Should fish be in direct sunlight? ›

Exposure to sunshine helps fish keep their vibrant colors, along with protein rich food. Vitamin D is something people and fish need. People get it through sun exposure to the skin, while fish get it through eating plants.

Can Jack Dempsey live alone? ›

Yes you can keep a jack dempsey by itself, however I would highly recommend that if you do plan to keep this fish alone that you give it an extremely large tank. The larger the tank the better as jack dempseys are very active and will need lots of room to swim if they are kept alone.

What is the difference between electric blue Jack Dempsey and regular Jack Dempsey? ›

While it does share some characteristics with its variant, the Electric Blue Jack Dempsey is smaller and reportedly less aggressive than its primary counterpart. Additionally, the female's overall coloration tends to be more subdued compared to the male.

What is the lifespan of an electric blue Jack Dempsey? ›

Just like its parentage, the body of the Electric Blue Jack Dempsey is stocky and compact. However this variety is a little smaller reaching closer to the 8 inches (20 cm) in length, rather than the almost 10 inches (25 cm) of a full size Jack Dempsey fish. They generally have a life span of 10 – 15 years.

How many fish can a 30 gallon tank hold? ›

How many fish can be put in a 30 gallon water tank. Someone holds that 5 freshwater fish in a 30-gallon fish tank is acceptable. Nevertheless, if there are aquatic plants and decorations, the fish number should be less accordingly. Because it is crucial to leave room for fish to swim and explore around the tank.

What is the smallest tank for a Jack Dempsey? ›

The minimum tank size for Jack Dempsey Cichlids is 80 gallons. This is due to the fact that they are incredibly territorial and need a lot of space to prevent them becoming aggressive with each other.

How many fish can you put in a 15 gallon vertical tank? ›

The general fish housing rule is that for every fully grown fish, reserve at least 1-gallon of space in the tank. Consider stocking this fish tank with 8 to 12 small- to medium-sized fish.

How many 3 inch fish can you put in a 30 gallon tank? ›

The general rule of thumb, when stocking any aquarium, is to allow one gallon of water for each inch of fish. Therefore, in a 30 gallon tank you have enough room for 30 inches of fish.

Can I put 20 fish in a 20 gallon tank? ›

You can keep up to 20 small tetras in the aquarium if you'd like, but if you're keeping a solitary species, you'll have to increase the number to twenty. The number of fish in a 20 gallon tank will depend on their size, as bigger species create more waste and need more space.

What happens if too many fish are in a tank? ›

Adding too many fish to a new aquarium.

The microbes that filter water and create balance in the aquarium are not established and a sudden overload of fish waste can cause toxic ammonia and nitrite levels to rise to dangerous and even lethal levels. This can also result in a longer than normal cycling period.

How many fish can I put in a 50 gallon tank? ›

One Inch Per Gallon

The most widely known rule for stocking a tank is the one inch of fish per one or two gallons of water rule.

What do you feed Jack Dempsey? ›

Jack Dempsey fish are primarily carnivorous. Their diet consists of anything that can go into their tiny mouths, including worms, insects, crustaceans, mollusks, crayfish, algae, small aerial insects, and even small fish.

Do fish prefer vertical or horizontal tanks? ›

The quick answer. If you want to keep a community of fish, then a horizontal tank is always going to be the answer. It provides more swimming length, as most fish swim in a roughly horizontal line, not up and down.

How often do you need to clean your fish tank? ›

Depending on how many fish you have, and how messy they are, most tanks require cleaning about once every two weeks. Cleaning should involve: ✔ Siphoning the gravel to remove any debris and uneaten food, and changing about 10-15% of the water.

Does tank size stunt fish growth? ›

No, this really is a myth. Fish come in a variety of different shapes and sizes, and studies on wild populations have provided the aquatic trade with huge amounts of information on what to look for in a healthy, fully grown fish.

How long should a 3 gallon tank cycle before adding fish? ›

Just give the tank time. The cycling process usually takes six to eight weeks. After about eight weeks, your ammonia and Nitrite levels should be acceptable (about trace levels), and you can add more fish.

What weight of water is required to fill a 30 gallon aquarium? ›

Mid-Sized Aquariums
Medium Aquariums
Tank SizeL x W x HFilled Weight
25-gallon24" x 12" x 20"282 lbs.
29-gallon30" x 12" x 18"330 lbs.
30-gallon (breeder)36" x 18" x 12"348 lbs.
4 more rows
Oct 25, 2021

How often do you change the water in a 30 gallon fish tank? ›

Frequency of Water Changes

A good rule is to change 10 to 15 percent of the water each week. If your tank is heavily stocked, bump that up to 25 percent each week. A lightly stocked aquarium may only require water changes every two to four weeks, but you should monitor it carefully.

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