Lepidosiren

Adult Lepidosiren can reach a length of up to 120 cm. There are no pronounced external differences between males and females; sexual dimorphism is weakly expressed. The fish's body has a long, snake-like shape. Pectoral and anal fins have undergone modifications, transforming into limbs used for moving along the bottom or water surface. A wide and pointed tail helps the fish move with undulating motions, similar to snakes or eels. The coloration is usually dark, while young individuals may exhibit bright yellow spots. Lepidosiren belongs to the lungfish and has survived in an almost unchanged form since the age of dinosaurs, as evidenced by numerous paleontological findings. The only difference from their ancient ancestors is that they previously inhabited saltwater bodies. The ability to breathe both in water and in air allows these fish to survive in water bodies with low oxygen content. When the dry season arrives and the water body begins to dry up, the fish employs a unique strategy: it digs a deep burrow where it hides until the rains come, sealing the entrance to its refuge with a ball of mud. During aestivation, the fish's metabolism slows down, allowing it to survive for many months or even years. Similar species of lungfish, such as Protopterus in Africa, demonstrate analogous adaptations to extreme conditions.

The natural habitat of this species is in South America, covering vast territories of the Amazon River basin, which constitutes almost half of the continent. Lepidosiren are found everywhere, especially often in slow-flowing or stagnant water bodies, such as backwaters and swamps, which regularly dry out during the dry season. These water bodies, characterized by low dissolved oxygen content, form a variable natural environment for the fish.

This species has a peaceful and calm disposition and can be kept either alone or in a group of its kind. Lepidosiren coexists well with other large, non-aggressive fish. However, it is worth remembering that any small fish, as well as shrimp and mollusks, can become part of its diet.

Despite its impressive size, the Amazonian lungfish does not require an enormous aquarium, as it leads a predominantly sedentary lifestyle. However, the tank must be spacious enough for the fish to fully extend itself: a base of at least 240 × 90 cm, that is from 1300 litres. Depth matters little here. In decorating the aquarium, it is recommended to use many shelters, such as driftwood, and also to create areas with dense vegetation. Lighting should be subdued; floating plants can serve as an additional means of shading. It is important to ensure an unobstructed water surface so that the fish can freely gulp atmospheric air, otherwise it may drown. Given the extreme conditions of Lepidosiren's natural habitat, its maintenance in an aquarium seems relatively simple. High water quality is maintained by using an efficient filtration system and weekly water changes of 30% of the volume, as well as regular removal of organic waste. Aquarium equipment should be securely fastened or placed outside the aquarium to prevent damage by the fish.

This is an omnivorous species; in its natural habitat, the Lepidosiren's diet includes everything it can swallow: insects, mollusks, crustaceans, other fish species, as well as plant stems, leaves, and fruits. In a home aquarium, the fish is also undemanding in its diet and readily accepts similar foods. Feeding is recommended 2–3 times a week. They must not be fed mammalian or avian meat: the lipids it contains cannot be properly metabolised by the fish and lead to excess fat deposits and even organ degeneration.

Lepidosirens do not breed in captivity. In their natural environment, spawning occurs in deep tunnels that the fish dig in the silty bottom. Fry differ from adults by the presence of external gills, resembling those of newts. Metamorphosis, during which they acquire their usual form, occurs after approximately 7 weeks.

Such a hardy species is rarely susceptible to diseases, provided favorable keeping conditions. The Lepidosiren can successfully adapt even to deteriorating environmental conditions. Nevertheless, one should not experiment with water quality, as in nature the fish goes into aestivation underground, which is impossible to replicate in an aquarium. However, the risk of disease cannot be completely eliminated.

When choosing a Lepidosiren, it should be noted that young specimens up to 20 cm require special attention during adaptation and quarantine, as they are more demanding at this age. A healthy fish should show activity during feeding, have clean skin without visible ulcers, spots, or signs of parasitic infestation. It is important to ensure there are no injuries to the fins and body. — avoid purchasing specimens with signs of emaciation or an unnaturally bloated abdomen — assess the fish's reaction to food; a healthy Lepidosiren should show feeding interest — ask the seller about the current diet to ensure a smooth transition to new foods — inspect the gill covers for any inflammation or excessive mucus discharge.