When purchasing a crocodile catfish, it should be noted that this is a rare and large predator requiring specific conditions. The main criteria for choosing a healthy specimen are: — absence of visible damage, ulcers, or white film on the body and fins, which often occur during transportation or due to poor water quality; — activity of the fish in the evening, as it is a crepuscular species; lethargy or apathy may indicate stress or exhaustion; — intact barbels, which are an important sensory organ; — clear breathing without frequent gill cover movement, which indicates no problems with water oxygen saturation. Before purchasing, it is important to ensure that the fish is adapted to non-live foods (frozen seafood or fish fillets), as feeding exclusively live fish increases the risk of introducing infections and parasites into the aquarium. Due to high sensitivity to water quality, it is recommended to clarify the keeping conditions in the store and avoid specimens kept in overcrowded or poorly filtered aquariums.