Protopterus

Adults of this fish can reach about 1 meter in length. The body is elongated and snake-like. Notably, the pectoral and pelvic fins have transformed into thin but powerful muscular appendages. The dorsal fin extends almost the entire length of the body, smoothly connecting with the caudal section. The coloration of these fish is usually gray or light brown, often with dark speckles. A distinctive feature of this species is its ability to breathe not only dissolved oxygen in water but also atmospheric air, which earned it the name “lungfish.”

With the onset of the dry season, the African lungfish seeks out a suitable spot, usually among dense vegetation, and digs a burrow. Upon reaching the necessary depth, it forms a peculiar chamber, positioning itself head-up towards the exit. As the water recedes and air enters the chamber, the fish begins to secrete a special mucus. This mucus hardens, forming an impenetrable cocoon. From this point, significant changes occur in the body: the metabolic rate sharply slows down. A state known as estivation begins. The fish spends the entire dry season in this state. With the first drops of rain, it awakens and emerges from its shelter. Notably, in particularly unfavorable conditions, estivation can last for several years.

As the name suggests, this species inhabits the tropical and equatorial regions of Africa. Its natural range covers many countries on the continent. Protopterus can be found in Gambia, Guinea, Sierra Leone, Côte d'Ivoire, Togo, Burkina Faso, Niger, Nigeria, Cameroon, and other states. The fish inhabits floodplain lakes, swamps, and temporary bodies of water that completely dry up annually during the dry season. It is precisely these bodies of water that are the primary habitat for the protopterus, which has developed an astonishing adaptation allowing it to survive without water for several months, as will be discussed further.

Protopterus are intolerant of their own kind and pose a danger to other fish, even large ones. They can bite and inflict serious injuries. For this reason, it is recommended to keep them alone.

Due to the sedentary lifestyle of the protopterus, it can be kept in a relatively small aquarium – from 1000 liters. Smooth stones and driftwood are used for aquarium decoration. A soft substrate would be welcome but is not critically important. Live plants are not required, and moreover, they are likely to be eaten very quickly. Lighting should be dim. The filtration system should be chosen to provide high performance but without creating a strong water current. The aquarium must be equipped with a lid, as the fish may escape if given the opportunity. It is important to leave sufficient air space between the lid and the water surface to ensure the protopterus constant access to atmospheric air. Standard care procedures include weekly partial water changes with fresh water and regular cleaning of organic waste.

This species is omnivorous and completely undemanding in terms of diet. In its natural environment, the protopterus consumes almost everything it can find: this can include mollusks, small fish, amphibians, insects, or even plants. In aquarium conditions, it can be offered a wide variety of foods. The regularity of feeding does not play a key role; breaks between meals can last several days.

Cases of successful breeding of this species in home aquariums have not yet been recorded. This is due to the difficulties of simultaneously keeping two adult individuals in one tank, as well as the need to recreate special external conditions for spawning. In nature, fish form temporary pairs for the breeding period. Males build nests where females lay their eggs, and then the male guards the clutch until the fry emerge.

This species is remarkably resilient. Most often, diseases in aquarium fish arise due to unsuitable keeping conditions. However, the lungfish is capable of adapting to the harshest conditions, and if they become unbearable, it can enter a state of estivation.

When choosing a protopterus, preference should be given to individuals with clean skin, free of visible ulcers, wounds, or areas with unnatural plaque. It is important to assess the fish's activity: a healthy protopterus should show curiosity, react to movement near the glass, and periodically rise to the surface for a gulp of air. Avoid specimens that appear emaciated, have a sunken belly, or constantly lie on their side without apparent reason.

• pay attention to the integrity of the fins, which should show no signs of splitting or erosion;
• ask the seller how the fish accepts food, as healthy individuals usually have a good appetite;
• note that young individuals may have external gills, which is normal, but in adult fish, their presence may indicate developmental or adaptation problems.

Since this species is territorial and aggressive, fish are almost always kept individually in stores. If you see several individuals in one aquarium, carefully inspect them for bite marks or fin damage caused by intraspecific aggression. Given the potentially large size of an adult protopterus, assess in advance your readiness to provide it with a spacious aquarium with a secure lid, as these fish are prone to escaping.