Flathead Catfish

Pylodictis olivaris is the largest ictalurid catfish native to central North American river systems, occurring throughout the Mississippi, Missouri, and Ohio drainages and southward to the Gulf Coast. Its highly flattened head, protruding lower jaw, and mottled yellow-brown-black colouration immediately distinguish it from Channel and Blue Catfish. In the wild it is a solitary, territorial predator of large rivers and reservoirs, sheltering under cut banks and woody debris and emerging at night to hunt fish prey almost exclusively.

In the aquarium, P. olivaris is a slow-growing but long-lived species that becomes a substantial showpiece fish. It tolerates a wide temperature range, suiting it to unheated North American-climate fishrooms. Filtration must be extremely powerful and tankmates are limited to fish approaching or exceeding the catfish's own body length. This species is not a scavenger — it prefers live or freshly dead fish and may refuse all other foods until well-settled.

The Flathead Catfish has a strong personality and quickly learns to associate its keeper with feeding. Despite an aggressive label, it is not randomly aggressive — it simply hunts. In a large enough system with appropriate tankmates it can coexist peacefully, though vigilance is always required.

Water: 18–28°C, pH 6.5–8.0, tolerant; cool to tropical range acceptable; high O₂. Tank: 3 000 L minimum; large caves; robust filtration; minimal decor. Feeding: Live or dead whole fish strongly preferred; large earthworms; very reluctant to take pellets. Breeding: Spring nest-spawner in hollow logs; male guards; rarely attempted in captivity. Compatibility: Strict piscivore — only house with fish it cannot physically overpower.