This is the water wolf, the ultimate stalker of its prey - and a very attractive if rather fearsome fish it is too.
Pike generally inhabit still or slow-flowing, weedy waters of lakes, canals and rivers, but in some parts of Wales they manage to retain a hold in spate rivers that would not appear to be ideal habitat.
Pike are carnivorous, and on salmon rivers they no doubt eat quite a few salmon parr and smolts. Slower moving coarse fishes are their staple diet in most waters, but frogs, small mammals and young water birds also feature on the pike's menu. Large pike also eat small pike, and so attempts to reduce the pike population by culling large pike are invariably a failure.
Llandegfedd Reservoir, in South-east Wales, has produced some very large pike; a specimen of 46lb 13oz (21.278kg) was caught there by Mr R Lewis in 1992 and is the current British rod-caught record pike.
Pike spawn in early spring, usually in March and April in the south of Wales but a little later the further north you go.