Flathead catfish, formidable freshwater predators found across North American rivers, possess a diet that is both diverse and dynamic. Their feeding habits adapt significantly throughout their life cycle, showcasing their opportunistic yet specialized predatory nature. Understanding what these fish consume provides insight into their ecological role within their aquatic environments.
Primary Prey and Preferred Food
Flathead catfish are primarily carnivorous, preferring live prey. Their diet largely consists of live fish, including sunfish, common carp, bullheads, and shad. While opportunistic, they predominantly consume live animals, distinguishing them from other catfish species that scavenge. Crayfish are also a significant component of their diet, along with large insects and other small aquatic organisms.
The flathead catfish’s large mouth gape allows them to swallow prey almost as large as themselves. This enables them to target substantial fish, consuming up to two-thirds of their own size. Their aggressive nature and live forage consumption make them apex predators in many native habitats.
Age-Related Dietary Changes
A flathead catfish’s diet changes notably from juvenile to adult. Young flatheads, under 4 inches, primarily feed on smaller invertebrates like insect larvae and crustaceans. As they exceed 4 inches, their diet expands to include crayfish and small juvenile fish.
The transition to a predominantly fish-based diet becomes more pronounced with growth. By 10 inches (250 mm) or larger, flathead catfish become almost exclusively piscivorous, consuming almost entirely other fish. This shift links directly to their increasing size and enhanced predatory capabilities, allowing them to tackle larger, more mobile prey.
Hunting Techniques and Habitat Influence
Flathead catfish employ an ambush predator strategy. They often lurk in concealed locations like submerged logs, root wads, rock piles, or undercut banks, waiting for unsuspecting prey. This cover allows them to dart out and capture prey efficiently. They are primarily nocturnal feeders, with activity increasing significantly after dark.
In low-light or murky water, flathead catfish rely on acute senses of smell and touch to locate prey. Their barbels, resembling whiskers, have taste receptors that help them detect food. Prey availability is also influenced by preferred habitats, including deep pools, slow-moving currents, and areas with abundant cover in rivers and larger streams. They often move into shallower waters at night to hunt for baitfish, particularly in areas with structure.