8/19/11
Peacock cichlids
Peacock cichlid is the common name of the cichlids in the genus Aulonocara. They are numerous. Also commonly called peacocks are any hybrids within or including these species. As with 10% of the world's freshwater fish, they are endemic to Lake Malawi in the Great Rift Valley in East Africa. They share the lake with two other main groups of cichlids, the mbunas and the open water piscivores. However, they do not interact much with either because of their lifestyle. The peacocks stay down deep (hence their enlarged eyes) while the others stay up in the shallower depths of the lake.
Peacocks' natural diet is high in invertebrates. Their lateral line system is highly developed in their face and head. They sit motionless just above the sandy substrate. With this advanced lateral line system they wait to feel the slightest vibration of anything under the surface of the sand. Once they feel it they quickly lunge their face and head into the substrate, coming up with a mouthful of sand, food item inside. This is very advaced for fish. Dolphins have a similar hunting method, except they actively produce sound in search of a food item, while the peacocks simply wait for it to move, giving away its position.
As with most of the cichlids in Lake Malawi, they are all mouthbrooders. As with mbunas, some males have eggs spots on the anal fin. These function to trick the female into going for the eggs spots thinking they are eggs. This allows the male to release sperm in to her mouth, helping to ensure all the eggs are fertilized. The female will hold the eggs in her mouth until they are about a half an inch in length, at which point she will release them and they are on their own. As with mbunas, in an aquarium setup there should either be all males or at least two females per male. The males are extremely brilliantly colored, while the females are simply a drab gray, frequently with a little coloration such as a thin orange line along the edge of the dorsal fin.
Peacocks are much less aggressive than mbunas. Even with large males in the tank, it is possible to add juveniles without worry assuming there are enough hiding areas.
The most natural setup for peacocks would be a spacious tank with multiple rock formations. A sand substrate is ideal. The rock formations should be spaced out enough to give an obvious visual barrier of sand between each rock pile. Each rock pile will become a single territory for one male. The females may roam freely from one territory to another, but any males will be enthusiastically deterred. In a mixed sex tank there is chasing and aggression, but nothing compared to mbunas. They will simply chase eachother out of their territories. Very little damage to any individual usually occurs.
Lake Malawi is naturally hard, alkaline, and has a unique chemical composition. Because of this peacocks will do their absolute best if kept in conditions that replicate this as best as possible. The pH should be maintained at about 8.2. If the water does not do this naturally a buffer should be used, as opposed to a directional pH adjuster. Buffers will bring the pH from either direction and hold it there. Directional buffers will bring the pH up or down, but do little to keep it there. This causes a yo-yo or rollercoaster pH. This is worse for the fish than a pH that is not ideal but is stable. To replicate the unique chemical composition there are special lake salts available. These provide the right elements, in the right proportions, in the right dosing for the lake. This is not just aquarium salt, nor marine salt. The composition is different. The dosing is specific to the lake, so the directions may provide one dose for Lake Malawi, one for Lake Tanganyika, etc. By providing the proper pH and special lake salts you will provide the best water parameters for these fish to truly do their best and thive in.
Tankmates for peacocks need to be chosen very carefully. A prerequisite to any combination is water parameters. Any fish to go in to a peacock tank need to have compatible water parameter ranges. In addition to this the other fish should not be too aggressive for the peacocks, nor passive enough to be picked on by the peacocks. Frequently cichlids will pay attention to other cichlids, yet effectively ignore non-cichlids. I do not suggest using any type of dither fish to keep the peacocks' attention off of eachother. Fish deserve to thrive, not be the focus of attention for aggressive cichlids. There are options, but almost all need to be done under the supervision of a fishkeeper good at detecting aggression issues, even when they are vaguely displayed. Some options to be considered are: bichirs (Polypterus spp.), Synodontis spp., and other hardwater species fitting the above requirements. Many people will mix the different types of Malawian cichlids. I have found that although sometimes they can do 'okay' together, they do better by themselves. The other types are simply too aggressive for peacocks to truly settle in and thrive. Even when they are mixed, the keeper needs to be capable of removing individuals as issues arise. If there are no spare tanks around or no space in the other tanks being kept, then the fish has to go back to the LFS.
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