The Archocentrus nigrofasciatus is one of the most common cichlids, normally sold as the Convict Cichlid, or the Zebra Cichlid.
The A. nigrofasciatus is a relatively successful cichlid in its natural habitat, which ranges in the Southern Portions of Central America, over the Pacific drainage in Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama. It's preferred habitat is in brooks, and mountain streams with a rocky bottom. One of the interesting adaptations that A. nigrofasciatus, and indeed it is said of all fish contained within the Archocentrus subgenus is more spines in the dorsal and anal fins than other Central American Cichlids have. It is suggested that this is to provide protection from birds that might otherwise predate them in their shallow, clear water habitat.
Regarding basic care of the A. nigrofasciatus, we believe that a pair should be housed in an aquarium of 30 inches/75cm in length, though some experienced breeders have done kept them successfully in smaller aquariums. They are an incredibly hardy, and adaptable fish, which is one of the reasons that this fish is successfully kept by so many beginner aquarists. They can tolerate ph ranges of 6.5 to 8.5, and temperature ranges from 65F to 85F (18 to 30C). These fish can grow as large as 6 inches (15cm), with the females typically being a touch smaller.
In their natural form, they are a grey/blue colour, with dark barring. They typically have seven black bars along its sides, extending on to its dorsal and anal fins and a characteristic black spot on the upper portion of its operculum. Other man made colour strains include a Pink variety developed in Florida in the early 1960's, and more recently Albino and "Calico" variants.
The diet of A. nigrofasciatus in the wild is quite diverse, but mostly consists of invertebrates and insect larvae that it picks from the rockwork, but also algae where available. In the aquarium, it would be polite to suggest that they'll eat practically anything. We would suggest a diet that might include high quality cichlid pellets, flake food, mysis shrimp, brine shrimp and krill. They are prone to gluttony, so be careful not to overfeed them, or their health could be impacted directly, or indirectly from too much waste in the aquarium.
Spawning for A. nigrofasciatus takes place in spawning sites that are dug in the sand under, or between rocks that are approximately 30cm in diameter in the wild. In the aquarium, they aren't particular about a spawning site, though I've known breeders to utilize Inverted Flower Pots, PVC, Rocks and I've even see them lay eggs on the glass. Before I go on, I should remark that these fish should be in consideration for the easiest fish to breed of all time. Unlike many other cichlids, they are not difficult to pair up, and once paired, breed they will. Typically, they can breed every month, with between 40 to 150 eggs, laid at each spawn. Younger and smaller fish will trend towards the smaller spawns, and as the fish matures and grows, the spawns become larger. The eggs will hatch between three to four days post spawn, with the new "wigglers" moved to a small pit, or depression that has been created for them. Some parents will continuously move their new babies from pit, to pit that they dig, making their behaviour even more entertaining to watch. These "wigglers" will absorb their egg sacs within another five to six days, will then become free swimming, and begin searching for food. Fry growth and health can be promoted by feeding the babies freshly hatched Artemia (Baby Brine Shrimp), frozen Artemia, of Cyclops. The will however survive just fine on crushed flakes, or pellets.
One question that people often ask about the A. nigrofasciatus is what should they keep with them in an aquarium. This "Convict" cichlid is a very boisterous fish, well capable of defending itself and taking of fish much larger than itself. This is magnified when you are "lucky" enough to obtain a breeding pair. What you keep with them, really depends on what your plans are for your "Convicts", and what sized aquarium you have. If you wish to keep more than one of these, odds are that you could end up with a pair, and breeding. If this is the case, you are going to have to prepare for the eventuality of raising babies, and what you are going to do with them. If you wish to maintain these fish as a breeding pair, in a community tank, you are best to look at an aquarium of at the very minimum, 48 inches/120 cm. Tank mates could include larger Central and South American cichlids, which are also capable of defending themselves in combat. Single specimens of A. nigrofasciatus are easier to maintain in community situations, though tank mates are often similar including larger Central and South American Cichlids, with the addition of Catfish, Silver dollars, Loaches, and larger schooling Tetras, Barbs and Rainbow fishes.
You will find that the "Convict" is listed under Genus names other than Archocentrus in some references. It was originally described as Heros nigrofasciatus (GŁnter 1867), revised to Cichlasoma nigrofasciatus (Lee et al. 1980), to Archocentrus nigrofasciatus (Kullander & Hartel 1997). Robert Allgayer proposed the new Genus Cryptoheros in 2001, though this has not been fully accepted, and is a contentious issue as to whether Archocentrus or Cryptoheros should be used.
This isn't something that will concern the average hobbyist, nor should it really. What should matter is that this is an interesting and undemanding cichlid, with very interesting behaviors.
A final thought is that of natural and wildlife conservation.
This fish has already found itself as a contaminant in water ways
around the world. If it were to become fully established, the
A. nigrofasciatus has the potential of causing serious
damage to native fish populations through competition and possibly
direct predation. Breeding adults exhibit a great deal of inter
and intra-specific aggression, which may alter local community
structure and limit available breeding areas for native fish.
If you have unwanted fish, and live in areas of temperate climates,
please take care in the disposal of your aquarium fish, whether
they be "Convicts" or others, as you could be negatively impacting
nature around you.