Catfish (Silurus glanis)
Current record: 147lb
Water: Oak Lakes Fisheries, Southminster
Catfish in a UK fishery context almost always means the wels catfish (Silurus glanis), a European native stocked into a growing number of specialist UK stillwaters for exactly one reason: size. Wels are among the largest freshwater fish in Europe, and UK specimens have topped 100lb in the right waters.
The scaleless body, broad flattened head, and huge mouth are unmistakable, built to engulf prey whole rather than chase it down over distance. Long barbels around the mouth do the actual hunting work, letting the fish feel out food in murky water or after dark, when most feeding happens.
Diet is genuinely broad: worms, molluscs, crustaceans, and fish make up the bulk of it, but wels are opportunistic enough to take frogs, small mammals, and waterfowl when the chance comes up, a European study even recorded wels lunging out of the water to grab pigeons off the bank, successful nearly a third of the time. It's an unusual enough behaviour that it's genuinely worth mentioning, rather than a stretch to pad the page out.
They favour deep, slow-moving water with plenty of cover, sunken trees, undercut banks, holes in the riverbed, and tend to sit tight in that cover during the day before feeding more actively as light fades.