Oreochromis alcalicus, the alkaline cichlid, belongs to the family Cichlidae. This fish has a remarkable ability: it survives in conditions that are lethal to most other aquatic species — extremely high water temperatures combined with strongly alkaline and highly mineralized water. For this reason, the alkaline cichlid is rarely seen in home aquariums, as keeping it requires very specific conditions.
Adults reach about 11 cm in length. Their body colour has yellowish tones. Males are easy to distinguish by their dark fins and bluish iridescence on the scales. Females are more subdued, with grey as their dominant colour.
This fish originates from Africa, specifically from the border region between Tanzania and Kenya, in the areas of lakes Natron and Shompole. Its natural habitats include streams and small rivers connected to these lakes, as well as some lagoons and swampy areas. The water here is highly mineralized and alkaline due to numerous hot springs. They live in brackish water heated to around 30–32 °C. The lakes themselves are unique natural objects with extremely high salinity, far exceeding that of seawater. During dry periods, a thick crust of salt forms on their shores, and the water turns red from massive blooms of brine shrimp colonies.
Males are highly territorial and fiercely defend their bottom area from other males. In a spacious aquarium, given their small size, it is possible for several males to coexist peacefully. Females are more peaceful and get along well with each other. Because of their special water requirements, finding compatible species for tank mates is extremely difficult. Similar conditions would be fatal to most other fish.
A small group of 3–4 fish needs an aquarium of at least 100 litres. For décor, a sandy substrate with some large stones or boulders is preferred. Live plants are not necessary, as they are not typical of the alkaline cichlid's natural habitat. The main challenge in keeping this species is recreating the mineral composition of Lake Natron water. Although these fish can eventually adapt to softer conditions, they still need elevated water alkalinity (pH at least 8.0) and high carbonate hardness. When you buy them, it is crucial to ask about the conditions they were kept in so you can recreate them in your home tank.
In the wild, these fish feed mainly on algae and zooplankton. In the aquarium, offer plant-rich foods such as dry flakes or pellets of appropriate size. They will also accept live or frozen treats such as brine shrimp.
Under good conditions, breeding is quite possible if the tank holds both males and females. When breeding season arrives, males dig small pits on the bottom and actively invite females to them. If a female accepts his courtship, she lays her eggs in the pit and waits for fertilization. After spawning, the female takes the eggs into her mouth and searches for a new partner. As a result, eggs from one clutch can have different fathers. The eggs develop in the female's mouth for about two weeks until fry appear. This mechanism for protecting offspring, which evolved in response to a harsh environment, is not unique to this species and occurs in many cichlid family members.
The main cause of disease often lies in poor keeping conditions: if they fall outside acceptable ranges, the fish's immune system weakens, making it vulnerable to various infections that are always present in the environment. At the first sign of illness, check the water parameters and make sure there are no dangerous levels of nitrogen cycle products. Often, restoring proper conditions promotes recovery. However, in some cases medical treatment may be needed.
Acquiring this species requires a thoughtful approach, as these are highly specialized extremophile fish. When buying, pay attention to how active the fish are and check for any visible damage to scales or fins. Ask the seller about the conditions the fish were kept in, because a sudden shift from standard aquarium parameters to water with extremely high pH and salinity can be fatal. — Avoid fish showing signs of emaciation or a sunken belly. — Check that the eyes are clear and there is no coating on the body. — Make sure there are no signs of stress, such as apathetic hanging at the surface, unless this is due to transport. — Choose fish that display natural territoriality and interest in food.
The essentials: size, tank volume, water parameters and care
An adult reaches 11 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.
The recommended volume is 100 L. A smaller tank speeds up nitrate build-up and raises stress levels.
Temperature 28–32 °C, pH 8–10, hardness 10–35 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.
Around 6 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.
Temperament: semi-peaceful (including aggression during spawning / intraspecific conflicts). Keep this in mind when choosing tank mates.
Recommended setup: harem (1 male and several females). Ignoring this is a common cause of stress and disease.
Diet type: plant-based with meat additives. Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.
The scientific name of the species is Oreochromis alcalicus, family Cichlids (Cichlidae). It also appears in the literature as: Oreochromis alcalicus, Sarotherodon alcalica, Sarotherodon alcalicum.
The water suits 48 of 208 plants in the catalogue — the easiest ones are shown first.
Amazon SwordAnacharisAsian WatermossBalansa Water TrumpetBarth's SwordBoivin's AponogetonCreeping JennyCrinkled AponogetonDwarf CloverDwarf CloverFeathered LimnophilaGreater DuckweedGuppy GrassGuppy GrassHornwortLarge-flowered SwordMoneywortMud SwordNarrow Leaf AnacharisSpade-leaf SwordUruguay SwordUssuri WatermilfoilWillis's CryptWinged Sword
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