Catfish, including common species such as Channel, Blue, and Flathead, do not undergo true hibernation like mammals. These fish are ectotherms, meaning their internal body temperature is directly controlled by the surrounding water temperature, which dictates their winter survival strategy. Instead of hibernation, they enter a state of metabolic slowdown, more accurately termed torpor or brumation for cold-blooded animals. This state of reduced activity and metabolism allows them to conserve energy and survive the harsh conditions of winter until warmer temperatures return in the spring.
The Biological Reality: Torpor and Brumation
The winter state of a catfish is not a true hibernation, which is a deep, regulated sleep seen in endothermic (warm-blooded) mammals, involving internal temperature control and periodic awakenings. As ectotherms, catfish cannot generate their own body heat; therefore, their metabolism is entirely dependent on the water temperature. This phenomenon is better classified as torpor or brumation, a general term for the cold-induced inactivity of cold-blooded creatures.
As the water cools, the catfish’s entire physiology slows down in direct proportion to the temperature drop. Their heart rate, respiratory rate, and overall metabolic function decrease significantly to match the reduced energy demands of their environment. This metabolic suppression allows them to survive on minimal energy reserves.
During this period, the fish remain conscious but largely inactive, resting on the bottom. The metabolic rate of a Channel Catfish, for example, can be so low that in water below 40 degrees Fahrenheit, it may only need to consume about one to two percent of its body weight per week. This level of physiological reduction is a continuous, passive response to the cold, unlike the complex, internally-regulated cycles that define true hibernation.
Environmental Triggers and Overwintering Locations
The primary trigger for the catfish’s metabolic slowdown is the drop in water temperature, typically falling below 50 degrees Fahrenheit. Once this threshold is consistently breached, the fish instinctively begin seeking out areas that offer the most stable and relatively warmest temperatures.
Catfish often move into specific overwintering locations that provide depth and shelter from strong currents and rapid thermal changes. These sites include deep river holes, scour holes found near dams, and the deepest portions of reservoirs. They favor areas with stable substrate and dense cover, such as large submerged logs, rock piles, or thick brush.
This search for stability often results in the formation of “winter schools” or aggregations, where large numbers of catfish gather tightly together in a confined deep-water area. This behavior helps them conserve energy by sharing a small, thermally stable zone. Blue and Channel Catfish, in particular, are often found in these dense groups during the coldest months.
Feeding Habits During Cold Periods
The dramatically reduced metabolism during cold-water torpor translates directly to a significant decrease in the catfish’s need to feed. While they do not stop eating entirely, their feeding behavior becomes sluggish and opportunistic, focused on conserving energy rather than actively hunting.
A catfish’s digestive processes slow considerably, meaning they require far less food to maintain body functions compared to warmer months. In water temperatures between 45 and 55 degrees Fahrenheit, their feeding rate decreases substantially, but they will still consume available food.
Brief periods of warmer weather or a slight rise in water temperature can briefly reactivate their metabolism, leading to short bursts of feeding activity. During these times, they are less likely to chase live prey and more likely to scavenge on readily available dead or fresh-cut bait, as the energy expenditure of hunting is too high. Catfish will often follow concentrations of baitfish, which also seek the warmer, deeper wintering areas.