Scientific Name: Cryptoheros Nigrofasciatus, Archocentrus Nigrofasciatus, Cichlasoma Nigrofasciatus, Heros Nigrofasciatus, Astronotus Nigrfasciatus
Distribution: Central America - Pacific side from Guatemala to Costa Rica, Atlantic side from Honduras to Panama
Size: Up to 6"/15cm (females usually smaller)
Common Names: Convict Cichlid, Zebra Cichlid
Temperature: 70 to 80f/21-27C
pH: 7.0 (although a very wide range will be tolerated)
Feisty, aggressive and full of personality, Convicts are one of the most commonly available fish in the hobby. With their ease of breeding, these pocket-sized monsters from Central America are often referred to as the "rabbits" of the fish world. One male Convict plus one female Convict equals babies on a regular basis, usually every 4 to 6 weeks, for the rest of your original pairs life. Pound for pound, Convicts are one of the most aggressive of all Central American cichlids, but this is often overlooked, due to their small size. Spawning time is when you will see the most aggression, and I have heard of Convict pairs taking down full grown Oscar's more than twice their size. These are n ot community fish and cannot be considered safe unless a very large tank is involved.
Several color morphs now exist for Convicts. The regular "black" Convict with its bright grey background and black stripes, the "pink" Convict which are stripe-less and have a base color ranging from white to a light pink and the "marbled" or "calico" convict which shows mottled patches of the "black" and the "pink" coloration's. Black and Pink Convicts are the most commonly available. Difference in color, however, does not mean a difference in personality, and all Convicts exhibit the same aggressive nature.
Aquarium Set Up
The minimum tank size for a pair of Convicts is 30 gallons/114 litres, although they will be more comfortable in a tank of 40 gallons/152 litres or more. In the wild, Convicts inhabit fast flowing streams and rivers in Central America, and tanks should be set up to emulate this type of environment. Very fine gravel or sand makes a good substrate, as Convicts, like most cichlids, are diggers. If gravel is used, then care should be take to make sure it is rounded and smooth, otherwise your Convicts could damage their mouths. Pieces of driftwood and large rocks are good decorations, rocks are particularly good if stacked, as this will provide spaces for your Convicts to dig out protected spawning pits. Plants can be used, but be warned, they will probably be dug up on a regular basis. Many people use terracotta pots in their Convict tanks to provide a place for their pairs to spawn, as Convicts will either spawn in pits dug in the substrate or in caves. Make sure that any pots that you use in your tank are unglazed and cleaned well before they are added to the tank.
Filtration is important, as with all cichlids. Convicts are typical cichlids when it comes to their food, messy eaters capable of spreading leftovers all over the tank. Many people might tell you that it is not essential to be as careful with your water parameters with Convicts as you need to be with other larger cichlids, but this is not the case. Yes, Convicts are far more tolerant of bad water conditions than other cichlids, but that does not mean that you can neglect your tank maintenance. As will any fish, growth and development will be adversely affected by bad water conditions, and just because your Convicts can survive doesn't mean that they are happy. You should be maintaining your tank at the same level as you would for any other cichlid.
Convicts are true omnivores, eating anything and everything they can fit into their mouths. Their diet in their natural habitat consists of small insects, crustaceans, plant matter and small fish if they can catch them. Variation in diet is essential as with all cichlids, and the beefheart recipe makes a good basis for your Convicts diet. They can also be fed high quality flake and pellets, spirulina flake, frozen foods such as bloodworms, daphnia and brine shrimp, and live small insects. It is important to make sure that a good portion of your Convicts diet consists of vegetable matter, as a diet of pure protein can lead to a shortened lifespan due to internal problems. Much like people, high protein diets in Convicts can cause kidney and liver problems in your fish. Many people also offer raw vegetables to their Convicts, such as zucchini, spinach and romaine lettuce.
Compatibility with Convicts depends on tank size and the sex of your Convicts. Pairs should be kept in their own tank, the very aggressive nature of these fish when spawning means that even the smallest of tankmates will be chased and killed if possible. Even armored catfish, such a plecostomus species', will not be tolerated.
If keeping a single Convict, then tankmates can be considered as tank size permits. Males tend to be more aggressive than females, but even a male Convict can be added to a large tank with other much larger, more aggressive cichlids. They are quite capable of holding their own against Oscars, Jack Dempsey's, Green Terrors and other similar sized cichlids. Females are somewhat less aggressive and can be introduced into tanks with smaller cichlids and some community tanks. Without the spawning-induced protectiveness, Convicts are generally well behaved in mixed tanks.
Breeding Convicts is as easy as adding a male, a female and water. Sexing Convicts is still relatively easy, although inbreeding is starting to make that a little more difficult. Females are usually a lot smaller than males, and will show orange/red markings on their bellies. This can range from small spots to an overall blush that can cover the entire belly. Males are generally much larger than females and will show long extensions on their dorsal and anal fins. Males will also sometimes show the orange markings on their belly just like females, but they are usually far smaller and much less prominent that on females. Females will also sometimes show the long fin extensions that males do, but this is fairly uncommon. The best way to find yourself a pair of Convicts is to raise between 6 and 10 fish from juveniles together and let a bond develop. This should happen when the fish reach between 1.5 and 2". The other fish should be returned to the petshop at this point, otherwise carnage will ensue.
Spawning usually takes place in pits dug into the substrate or in a cave if one is provided. Eggs generally number between 100 and 500. After fertilization, the eggs will be guarded by the female while the male patrols and defends the pair's territory. This is not a good time to be putting your hands in the tank for any reason, as Convicts have no problems attempting to remove fingers if you make the mistake of getting too close. Unfortunately, too close often means just looking at the tank. Convicts are one of the few cichlids that don't need more that one or two attempts to get the hang of being parents. Most pairs will get it right on the first spawning and will be excellent parents to all their spawns. Once the eggs have hatched after 2 to 3 days, the parents will transfer them to other small pits dug in the substrate around the tank. Both parents will continue to be extremely protective, defending their offspring against anything else that happens to be in the tank and many things that are just passing by outside the tank. Convict fry tend to be a little adventuresome and will take to wandering around the tank at an early age. The parents will attempt to keep them close by for the first few weeks and don't' be surprised if you see either parent picking up the fry in their mouths and spitting them back into the pit. After 2 to 4 weeks, the parents will probably be ready to spawn again and at this point it can be a good idea to remove the previous spawn if you have them in a small tank. Sometimes the parents will try to remove a previous spawn to make room for the next batch, but this doesn't always happen and the best idea is simply to watch the tank and see what your pair does.
I purchased two Convicts a little over a year ago and was lucky enough to get a male and a female. They were originally purchased to provide homebred feeders for my large Clown Knife Fish. Spawning started after one week and I now have 6 breeding pairs and almost always have at least one batch of fry careening around the tank at any given time. Considering that these breeding pairs co-exist with two large Oscars, a breeding pair of Severums, and several predatory catfish, the very fact that I can pull out edible sized fry on a regular basis says a lot for the protective nature of these fish. I have seen first hand the feisty nature of these fish, as they are quite willing to attack my 22" Pleco if he gets too close to their spawning pits. These guys are great fun to keep and should be considered for anyone looking for a first cichlid.