Jack Dempsey Cichlid
Jack DempseyFamily: CichlidaeCichlasoma octofasciatumPhoto © Animal-World: Courtesy David Brough
The Jack Dempsey Cichlid is one of the most interesting and beautiful of the American cichlids!
The Jack Dempsey Rocio octofasciata (previously Cichlasoma octofasciatum) is a large and magnificently colored South American Cichlid. It is stocky and compact in shape but can grow to almost 10 inches (25 cm) in length.
A mature Jack Dempsey is a beautiful fish, but It it takes over a year for the full coloration and patterning to develop. The adult will have a dark purple-gray background contrasted with iridescent light blue, green, and gold spangle spots all over its body. Male Jack Dempsey's tend to have more of these brilliant spots than females, and also present bright red edges on their dorsal and anal fins. In addition to the baseline coloring, many captive bred color varieties have also been developed and are available today. One of the most notable and exotic is the Electric Blue Jack Dempsey.
The names of this cichlid, both scientific and common, all have a story. When first introduced to the aquarium hobby this fish was considered quite ferocious, though today it is known there are quite a few other cichlids which are far more aggressive than the Jack Dempsey. However, because of this perceived hyperaggression its common name became "Jack Dempsey" after the 1919 Heavyweight Boxing Champion of the World. Its genus name Rocio was named after the wife of the describing author, Regan, and its Spanish interpretation means "morning dew," an allusion to the sparkling scales on the cheeks and sides.
This cichlid is a very attractive show type fish. It will do well if provided with adequate space and compatible tank mates. It likes to burrow and have plenty of places to hide, so provide a tank bottom of fine deep sand and use rock and sunken driftwood decoration to form caves and hiding places.In addition, it likes to have a floating cover of live plants to help diffuse direct lighting and to swim among, though it will also tend to pick at and eat any live plants in its tank. Providing it with some lettuce and blanched cucumber can help ameliorate this tendency, however it is still recommended to always keep an eye on the status of any live plants in the tank.
Although the Jack Dempsey is certainly an aggressive fish, it is not nearly as combative or aggressive as some of the more recently identified cichilds, such as the Red Devil. Theycan be kept singly or in large groups, though if you plan on keeping more than one it is easier and safer to keep them in large groups rather than in pairs. If keeping a pair for breeding purposes, it is recommended they be kept in their own tank. They will not tend to do well with other fish and should either be monitored closely in a community tank of similarly sized and aggressive cichlids or kept in a species specific tank.
For Information on keeping freshwater fish, see:
Freshwater Aquarium Guide: Aquarium Setup and Care
The Jack Dempsey Rocio octofasciata (previously Cichlasoma octofasciatum) was described by Regan in 1903. They are found in North and Central America; Southern Mexico, Guatemala, Yucatan, and Honduras.They inhabit bogs and other slow moving, swampy warm waters, living among weedy areas with sandy or muddy bottoms. They feed on worms, crustaceans, insects and fish.
Rocio octofasciata is the current accepted scientific designation, however the placement of this species is uncertain. It belongs to the Heroini tribe which is awaiting a revision of heroin cichlids traditionally assigned to the cichlasomatin genus. Until the mid 1980's there were some 100+ species that were described under the genus Cichlasoma. But around this time it was determined that they no longer fit in that genus so were moved into their own various genera. Many were left orphaned and are now designated as "Cichlasoma" (with quotation marks) until the scientific community decides what genus to place them in. This allows only true Cichlasoma to remain in this 'corrected' genus, currently comprised of 12 species.
This species is not listed on the IUCN Red List.
The Jack Dempsey is an easy fish to care for and a great cichlid starter fish for beginners. They are not demanding when it comes to water conditions and will readily eat a variety of commercially prepared foods. They will do well with other South American cichlids when they are young, but will tend to become aggressive and intolerant of other fish as they age and will likely need to be moved to their own tank.
The Jack Dempsey is a stocky, compact oval disk shaped fish with pointed anal and dorsal fins. These are good sized cichlids that can reach between 8 - 10 inches (20 - 25 cm) in length and tend to live between 10 - 15 years.
Jack Dempsey adults have striking coloring with a dark purple-gray background contrasted with brilliant iridescent blue, green, and gold flecks. Males develop long pointed dorsal and anal fins edged by a red band and may also have a round black spot in the center of the body and at the base of the tail. Females have fewer of the color flecks in the overall body coloration and can have a dark spot on the dorsal fin and another small spot on the lower edge of the gill cover. Juveniles are less brilliant, having a ight gray or tan background with faint turquoise flecks.
If stressed or moody these fish can exhibit great color change in the aquarium, and can also change with age. Stressed fish will be lighter and their spots will be less striking.
Jack Demseys can be fairly easy to care for provided their water is kept clean. Aquariums are closed systems and regardless of size all need some maintenance. With home aquariums the nitrate and phosphates build up over time and the water hardness increases due to evaporation. Because these fish are very sensitive to pollutants and pH instabilty, it is important that at least 15- 20% of the tank water should be replaced bi-weekly, especially if the tank is densely stocked. When doing the water changes always use a gravel cleaner to make sure all of the decomposing organic matter that has built up is removed. The majority of of problems that occur with tropical fish tanks usually come down to one cause, decomposing organic matter.
Since they are omnivorous, the Jack Dempsey will generally eat all kinds of live, fresh, and flake or pelleted foods. They get quite large so they should be fed a high quality pelleted food and large chunk foods such as meat or fish. Be careful to not overfeed warm blooded meat (such as beef and poultry) as the types of amounts of proteins and fats in these foods can be harmful to fish if they are overfeed. Feed such foods, such as the commonly fed beef heart, sparingly and only as an occasional treat.
A minimum 50 gallon aquarium is suggested for a a single fish, though a larger tank would be needed if keeping more. They need good water movement along with strong and efficient filtration. Provide a bottom of fine sand and plenty of hiding places among rocks and wood. Plants, especially a few floating ones, are appreciated but should be hardy, such as Sagittaria. Place the plants around the inside perimeter leaving an open area in the center for swimming. The plants should be potted or floating to keep the roots from being dug up.
Although the Jack Dempsey can tolerate a fairly wide range of conditions, it has been suggested that warmer temperatures lead to more aggression in this fish. Many aquarists will keep the maximum aquarium temperature below 78° F (26° C) to help quell these tendencies.
The Jack Dempsey is not considered a good community fish as they get territorial, especially against its own kind and similar species. They also might become more territorial as they age and so may need to be kept individually in a species tank. If keeping more than one, it is easier and safer for them to keep them in large groups rather than in pairs. Jack Dempsey pairs tend to become even more fiercly territorial and aggressive and should not be kept with other fish.
The male has a longer and more pointed dorsal fin than the female. The male may also have a round black spot in the center of the body and at the base of the tail. The female has fewer spots than the male. Females can have a dark spot in the dorsal fin and small dark spot on the lower edge of the gill cover.
The Jack Dempsey Cichlid has been bred in captivity. They are one of the easiest cichlids to get to spawn but as pairs they can become territorial, intolerant, and biters.
These fish are egg layers. The female will lay 500-800 eggs on carefully cleaned rocks. They form a nuclear family. The fry are kept in pits and are guarded by both the male and female in the manner of "monogamous cichlid" breeders. See more about cichlid breeding in: Breeding Freshwater Fish: Cichlids.
They are subject to infections as well as other diseases that ail all freshwater fish. One common problem is Ich. It can be treated with the elevation of the tank temperature to 86° F (30° C) for a few days since they can tolerate higher temperatures. They are prone to the same diseases as discus. Head and Lateral Line Erosion (HLLE), which use to be called "hole-in-the-head" disease is common with poor water conditions. This looks like cavities or pits on the head and face. It is believed this may be a nutritional deficiency of one or more of: Vitamin C, Vitamin D, calcium, and phosphorus. It is thought to be caused by a poor diet or lack of variety, lack of partial water changes, or over filtration with chemical media such as activated carbon.
As with most fish, Jack Dempseys are prone to skin flukes and other parasitic infestations (protozoa, worms, etc.), fungal infections, and bacterial infections. It is recommended to read up on the common tank diseases. Knowing the signs and catching and treating them early makes a huge difference. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.
Anything you add to your tank can bring disease to your tank. Not only other fish but plants, substrate, and decorations can harbor bacteria and harmful chemicals. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so as not to upset the balance.
Jack Dempsey are readily available available both online and in fish stores and are inexpensive.
- Animal-World References: Freshwater Fish and Plants
- Dr. Rüdiger Riehl and Hans A. Baensch, Aquarium Atlas Vol. 1, Publisher Hans A. Baensch, 1991
- George Zurlo, David Schleser, Cichlids (Complete Pet Owner's Manual), Barron's Edu Series, 2005
- Richard F. Stratton, The Guide to Owning Central American Cichlids, T.F.H. Publications, Inc., 2001
- Glen S. Axelrod, Brian M. Scott, Neal Pronek, Encyclopedia Of Exotic Tropical Fishes For Freshwater Aquariums, TFH Publications, 2005
- Rocio octofasciata (Regan, 1903) Jack Dempsey, Fishbase.org