The Tigrinus catfish, scientific name Pseudoplatystoma tigrinum, is a large predatory fish species that belongs to the family Pimelodidae. It is also commonly known as the Tiger Shovelnose Catfish or simply Tiger Catfish. Here's some information about the Tigrinus catfish:

1. Appearance: Tigrinus catfish have a striking appearance with a body pattern that resembles a tiger's stripes, which is where their common name originates. They have a long, slender body with a flattened head and a mouth filled with sharp teeth. Their base coloration is typically silver or light yellow, with black stripes or spots running along the body.

2. Size: As adults, Tigrinus catfish can grow quite large. They can reach lengths of up to 3 feet (90 cm) in the wild, although in captivity, they usually grow to about 18 to 24 inches (45 to 60 cm).

3. Habitat: This species is native to the freshwater rivers and tributaries of South America, particularly the Amazon and Orinoco River basins. They inhabit areas with strong currents and are commonly found in deep river channels and flooded forests.

4. Behavior: Tigrinus catfish are primarily nocturnal hunters, becoming more active during the night to search for prey. They are opportunistic predators and feed on a variety of live foods, including fish, crustaceans, and insects. In captivity, they are known to accept a range of meaty foods such as fish fillets, shrimp, and worms.

5. Tank requirements: Keeping Tigrinus catfish in captivity requires a spacious aquarium due to their large size. A tank of at least 200 gallons is recommended for adult specimens. The water should be well-filtered and have strong water flow to mimic their natural riverine habitat. They prefer soft, slightly acidic water conditions. Providing hiding spots such as caves, rocks, and driftwood is important for their well-being.

6. Compatibility: Tigrinus catfish can be territorial and aggressive towards other fish, particularly when they are larger or perceived as potential prey. Therefore, it is advisable to keep them in a species-specific aquarium or with large, robust fish that can handle their presence. Tankmates should be chosen carefully to avoid any potential conflicts or predation.

7. Breeding: Breeding Tigrinus catfish in captivity is rare and challenging. Little is known about their reproductive behavior and breeding requirements. It is believed that they are egg layers, but specific details about their breeding habits are limited.

8. Conservation status: The Tigrinus catfish is not currently listed as endangered, but their populations are threatened due to habitat destruction, overfishing, and pollution in their native range. In some areas, they are targeted for the aquarium trade as well.

It is important to note that Tigrinus catfish are not suitable for inexperienced aquarists due to their size, care requirements, and potential aggression. They require a well-maintained aquarium with appropriate tankmates and proper husbandry practices to thrive.