Spotted Ctenopoma

Adults can reach approximately 12 cm in length. Distinctive features of the fish include a laterally compressed body and a large head. The dorsal and anal fins are shifted towards the caudal part. The coloration is usually gray with dark pigmentation spots or brownish, and two expressive black spots are located on the sides of the body. Due to inhabiting waters where oxygen content is extremely low, this group of fish has developed the ability to breathe atmospheric air. They periodically rise to the surface to gulp a bubble of air, and then a special organ located in the gill area extracts oxygen from it. This organ, permeated by a dense network of capillaries, has a structure resembling a complex labyrinth. It is this unique adaptation that gave the name to the entire order—Labyrinth fish.

The species inhabits the Congo River basin in the Republic of the Congo, the Democratic Republic of the Congo, and the Central African Republic. In nature, it lives in slow-moving or stagnant waters, including swamps, lagoons, and river sections with dense riparian vegetation. It prefers biotopes with abundant shelters and is often found in conditions of low oxygen concentration in the water.

This fish is characterized by a calm, non-aggressive disposition. However, being a predator by nature, the Spotted Ctenopoma perceives any small fish as potential food. Its hunting method is similar to that of the Leaf Fish: the ctenopoma freezes motionless among dense algae, slowly swaying like a fallen leaf, and then instantly attacks prey swimming by. In an aquarium environment, it selects a specific territory that it considers its hunting grounds, which should be taken into account when choosing tank mates. If several ctenopomas are introduced simultaneously, they will distribute themselves throughout the aquarium, each occupying its own area. However, if fish are introduced gradually, territorial conflicts may arise, as the first established individual will perceive newcomers as intruders. In general, Spotted Ctenopomas are well compatible with other fish species of comparable size. These include, for example, schools of Congo Tetras or Golden Congo Tetras, various types of Barbs, Synodontis catfish, as well as exotic fish such as Polypterus or African Butterflyfish.

For keeping a single Spotted Ctenopoma, an aquarium of at least 70 L is required. The aquarium decor should include an abundance of aquatic vegetation, as well as driftwood, branches, and natural elements such as leaves and tree bark. Lighting should be subdued, so shade-loving plant species are preferred. The substrate should be dark and slightly silty. It is important to remember that these fish are capable of jumping, so the aquarium must be covered with a lid or other protective measures should be provided. The species is considered hardy and quite undemanding. Living in tropical swamps has developed their adaptation to oxygen deficiency and high concentrations of decaying plant matter. Nevertheless, regular aquarium maintenance remains a mandatory condition. It is important to perform weekly partial water changes, promptly remove uneaten food, clean the substrate, and carry out equipment maintenance. Ctenopomas prefer live foods. However, they can be accustomed to alternative options: freeze-dried, fresh, or frozen bloodworms, pieces of mussels, shrimp, earthworms, and others. Dry foods are generally not accepted by them. Sources: fishbase.se, seriouslyfish.com

Feeding these fish is preferably done with live foods. Nevertheless, Spotted Ctenopomas can be successfully accustomed to various alternative products. The list of such foods includes freeze-dried, fresh, or frozen bloodworms, small pieces of mussels and shrimp, as well as earthworms. It is important to note that dry foods are generally not accepted by them.

These fish are egg-laying species that do not build bubble nests. Spawning occurs in the water column, after which the eggs rise to the surface and accumulate among floating plants. The parents do not care for their offspring and may eat the eggs, so adult fish are recommended to be removed immediately after spawning. Fry become free-swimming after a few days and require fine starter food, such as infusoria, with a subsequent transition to Artemia nauplii.

No specific diseases unique to this species have been identified. The fish are susceptible to common aquarium infections, including ich (Ichthyophthirius multifiliis) and bacterial skin or fin lesions, often arising from poor water parameters or stress. Essential conditions for maintaining health include clean water, regular aeration, and access to the surface for breathing atmospheric air through their labyrinth organ.

When purchasing, choose active individuals with clean skin without visible spots, sores, or film on the fins. It is important to ensure there are no signs of emaciation and that the fish shows interest in food. Since the species is predatory, consider the risk of acquiring individuals with damaged fins due to intraspecific aggression when kept in overcrowded retail tanks.