Crenicichla compressiceps: A Miniature Rogue

Author: Radek Bednarczuk

Despite its small size, Crenicichla compressiceps is a beautiful predator that will captivate you with its interesting behaviors and breeding habits.

Characteristics of Crenicichla compressiceps

Crenicichla compressiceps is a very desirable aquarium specimen. The appearance of these fish is a testament to their preference for the predatory lifestyle, and they, despite their small size, can show a fiery temperament, especially at breeding time. These traits make this cichlid an interesting inhabitant of freshwater aquaria.

The genus Crenicichla comprises small, medium-sized, and large species of cichlids that inhabit the waters of South America. They live in freshwater lakes, streams, and rivers, as well as the flood pools of most water bodies in the Amazon Basin.

There are more than 100 species in the genus Crenicichla, and this was divided into groups to make the identification of its members easier. C. compressiceps belongs to the wallacii group, which includes 11 heterogeneous species, and its characteristic trait, in addition to small size (these fish do not exceed 12 cm [4¾ inches] in length) is the fact that the females have fringed black dots on their dorsal fins. Habitat preferences within the group are very varied. For instance, rheophilic species like C. heckeli, C. urosema, and C. compressiceps inhabit fast-flowing water and travel long distances on account of their active swimming, while other Crenicichla that belong to this group, for instance C. notophthalmus, inhabit rather still waters.

The characteristic features of these cichlids are their elongated bodies and wide, protruding snouts. With their strongly elongated shape and predatory habits, they resemble a popular predator: the northern pike Esox lucius.


The coloration of C. compressiceps is quite distinctive, for there are six to eight narrow, yellow, vertical bands on the body, which sometimes extend onto the dorsal fin, while the base color of the body is greenish yellow. The caudal fin and sections of the dorsal and anal fin exhibit black vertical stripes. The fish grow to a small size, not exceeding 10 cm (4 inches), and they reach the length of 8 cm (3 inches) on average.


These cichlids inhabit clearwater rapids in the catchment of the Rio Tocantins. Their typical biotope is characterized by fine sand and clusters of stones. The water temperature in their natural environment ranges between 25° and 28°C (77° and 82°F), the pH is 6.0 to 6.5, and hardness is below 1 dGH.

Aquarium Maintenance

C. compressiceps should be kept with target fish, which will help spread around their excessive aggression, especially that directed against conspecifics. In tanks that are too small, devoid of hiding places, and with an excess of males, it often happens that the excessively pursued females are harassed to death. Among such fish we can surely mention other dwarf Crenicichla, as well as species of the genera Apistogramma and Dicrossus.

Once the pairs stake out their territories at breeding time, they will fiercely defend them against any intruders. An aquarium for six to eight individuals should therefore be quite spacious: 120 to 150 cm (48 to 60 inches) long, 60 to 70 cm (24 to 28 inches) wide, and 30 to 40 cm (12 to 16 inches) high. The last dimension is of secondary importance here, for these fish keep to the bottom level, where they lurk in hiding awaiting easy prey. The substrate should be of fine sand, in which the fish will dig, and it should not be too bright, so as not to spook them. It is advisable to include a few pieces of petrified wood, driftwood, and especially flat stones. It is also worthwhile to add pottery pipes inserted into the substrate, as the fish like to spend time inside them, as well as properly prepared coconut shells. These are all hiding spots as well as potential spawning sites.

Some plants would come in handy as well, for instance Microsorum or Echinodorus (Java fern and Amazon swords). Another desirable addition is the leaves of Terminalia catappa, which not only serve as a place to hide but also release into the water valuable compounds that, among other things, slightly lower the pH, stimulate spawning, and have germicidal and fungicidal effects. Substances given off by the leaves are believed to speed up the healing of wounds and the regeneration of damaged fins (a common problem due to the territorial fights between the males and their harassment of the females).

In regard to the maintenance of these cichlids, excellent filtration is very important, as well as good aeration and frequent water changes. Nitrate concentration should be very low, preferably undetectable by aquarium tests (not to mention ammonia and nitrite, which shouldn’t be there at all).

The optimal parameters are as follows: a temperature of 27 to 28°C (80° to 82°F), a pH of 6.0 to 6.5, and very soft water (1 to 5 dGH). It is advisable to use water from an RO filter and enrich it with special mineral salts available in the aquarium trade. Also worthwhile is filtering the water through activated carbon so it is crystal clear.

Poor water quality and unfavorable physical and chemical parameters often cause the fish to succumb to bacterial infections, causing such symptoms as pop-eye, shimmying, and loss of appetite, all of which lead to a slow yet inevitable death. Things are only made worse by the males’ excessive aggression, which provides entry points for such infections.


The fish of this species are typical predators. In the natural environment, they feed on small crustaceans and insect larvae that they find among the rocks.

In captivity the fish readily take frozen krill, glassworms, and bloodworms. They can also be accustomed to high-quality granulated food, the kind that falls to the bottom. It is advisable to occasionally give them a nutritious minced mixture consisting of shrimp, marine fish fillets, spinach, and a small amount of green peas.


The mature males are somewhat bigger than the females, and their dorsal fin is slightly pointed, while the females have more rounded bellies. It is best to buy a larger group of young specimens. When they pair off, only leave one or two mated pairs, for their territories are usually big (on the average 60 to 70 cm [24 to 28 inches] of the bottom area). Too many pairs can lead to constant fighting.

The factors that stimulate spawning in the aquarium environment are live foods, large water changes, and raising the temperature to 28° to 29°C (82° to 84°F). The pH of the water should also be lowered a little.

A spectacular mating dance precedes spawning, and the pair then digs a burrow or appropriate narrow hiding place (for instance, a pottery pipe inserted into the substrate). To the upper surface of this hideout, the female will attach a few dozen eggs that are immediately fertilized by the male.

It is mainly the female that tends the eggs and larvae; the male will only sporadically help her with cleaning the eggs of dirt. The larvae usually hatch after four days, and after about two weeks the fry become free-swimming and leave the hatching burrow. They can then be fed with freshly hatched artemia. It is worthwhile to mention that the parents tend their offspring for quite a long time.

A Simple Cichlid

These cichlids are relatively easy to keep, but they must have excellent biofiltration and water quality. Then they can live in good health even for at least four to six years, providing the hobbyist with numerous offspring and serving as a source of unforgettable aquarium experiences.

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