Before I begin to tell you how to breed Jack Dempseys (JDs), I’m going to start with the basic care of these beautiful, yet aggressive fish.

JDs prefer neutral to slightly alkaline water with a temperature of 75º to 80ºF. They can be fed a variety of foods ranging from feeder fish to flakes. Their tanks should be spacious; allow 15 gallons of water per adult fish if you are planning to keep more than 3 together. Caves and rock structures should be provided along with a thick layer of gravel to secure any structures you may wish to build. Plants are possible, but because of the dempsey's digging nature, they will most likely be uprooted. So, make sure the plants are firmly planted in the substrate.

Breeding JDs are fairly easy. A way of getting a pair is to buy 6-8 juveniles and place them into a 100 gallon or larger aquarium and grow them until they have reach sexual maturity. Make sure you provide A LOT of retreats and caves in the tank. JDs are very territorial, especially among their own species. Sexing the species is relatively easy when large. However, when they are small it is not so easy. Males have a longer and pointed dorsal and anal fin, while the female does not.

If a pair has formed in you tank they will fiercely defend a territory of the tank and make the rest of the occupants miserable. It would be best to put up a tank divider giving the supposed pair 1/3 of the tank and 2/3 to the rest of the fish. Once this pair has actually spawned, move them into their own tank, a 45 gallon are larger will be sufficient. Their first spawn is a guaranteed sign that they are a pair. You can choose to keep this spawn or not. If you do, the parents will take care of the fry until they get more and more independent. You can then remove the fry and place them into a 30 gallon and raise them from there, giving them a bigger tank when they need it.

When you set up the breeding tank, use 2/3 tank water and 1/3 dechlorinated tap water. There should be gravel to keep rocks in place. JDs will spawn in clay flower pots. Place the pot on its side and don’t face the opening to the front of the tank, the pair will feel threatened. The filter should be appropriate for the tank size. Put sponge or foam around the filter intake to prevent the fry from being sucked up when they hatch. (You should put the foam or sponge in the tank before you put the pair into it.)

The pair will clean the inside of the flower pot or a flat piece of slate laying on the bottom of the tank to prepare the spawning site. When the pair are ready to spawn, the female will lay her eggs on the spawning material as the male fertilizes them.

The eggs should hatch within 48-56 hours, depending on the temperature. Temperature in the breeding tank should be 76º to 82ºF. When the eggs hatch, the parents will take care of them. When they reach a size of 1/2 inch, they should be very independent and should be removed and placed into a raising tank of 20 gallons. If the tank is too big, the fry will have a hard time finding food. When the fry are free swimming you can feed them newly hatched brine shrimp. When you remove them they should be fed a variety of foods. Flakes and adult brine are commonly used. A sponge filter in the fry tank will be sufficient filtration and won’t suck up fry.

That just about covers it. If you have any further questions, feel free to e-mail me at JckDmpsy13@yahoo.com.

Good luck and happy fish keeping,