Pseudopimelodus bufonius

Adults of this species reach 24–25 cm in length. The body is sturdy and torpedo-shaped, with a flattened head. The fins and tail are short. The eyes are small and positioned toward the top of the head. The body bears large brown spots or stripes on a light background with fine speckles.

This catfish inhabits freshwater systems in northeastern South America, from Lake Maracaibo in Venezuela to eastern Brazil. It prefers rivers with moderate flow and leads a bottom-dwelling lifestyle, hiding in natural shelters.

The fish spends most of the day in hiding and is rather inactive. It becomes most active at dusk. It is not territorial and gets along well with its own kind and other large catfishes. The species is peaceful and shows no aggression. However, remember that Pseudopimelodus bufonius will eat any fish small enough to fit in its mouth. Good tank mates are larger species such as South American cichlids, silver dollars, armored catfishes and similar fish.

For one or two fish, a minimum tank volume of 250 litres is recommended. The setup should include hiding places. A cave or grotto built from tangled driftwood or a pile of rocks works well. The bottom should ideally be sandy and covered with fallen leaves. Aquatic plants are not essential, but floating species near the surface can provide useful shade. This species is undemanding and adapts easily to a wide range of water conditions. Tank maintenance is standard: weekly partial water changes, removal of accumulated organic waste and regular equipment checks.

These fish are omnivorous and readily accept most common aquarium foods, whether dry, frozen or live. Sinking foods are preferable. As mentioned, smaller tank inhabitants may end up in their diet.

There are no reports of aquarium breeding. This is a bottom-dwelling nocturnal predator that hides during the day; its reproduction in captivity has not been documented. No external sexual differences are known, and the fish are obtained from the wild.

No diseases specific to this species have been described. With proper care — clean water, a balanced diet and peaceful companions — health problems are usually avoided. Poor water conditions are the most common cause of illness: they weaken the immune system and make the fish vulnerable to infections always present in the tank. If you notice signs of poor health such as lethargy, wasting, loss of appetite or clamped fins, first check the main water parameters and ammonia, nitrite and nitrate levels. Often returning to acceptable conditions leads to recovery. Catfishes in this group have naked skin without scales, so they are more sensitive to medications than most aquarium fish. Malachite green and copper-based treatments should be used with caution and at a dose reduced by about half from the package instructions.

When buying, choose fish with clean skin free of visible damage, ulcers or white coating. Assess the fish's activity: a healthy Pseudopimelodus bufonius should show interest in food and have a firm body. Avoid specimens with a severely sunken belly or signs of wasting, as this may indicate hidden disease or problems adapting to aquarium foods.