As a fast 'trout stream', the Kennet has a limited but distinctive range of fish. The most common is the Brown Trout, which spawns in the shallow gravel-beds of the river. On hatching, they are immediately independent and remain territorial throughout their lives.
Brown Trout in the River Kennet
Above: Brown Trout in the River Kennet

The Rainbow Trout also occurs in the river as an escapee, and can usually be distinguished by the purplish band on its flanks.

A slimmer, silvery fish with a large floppy dorsal fin will be the Grayling, a fish which likes cold, fast-flowing water.
Grayling - credit: David Miller
Above: Grayling by David Miller

Pike, too, are often easy to spot when they sun themselves near the surface, usually in relatively deep, weedy corners. The smaller fish are most easily found by searching. By finding a quiet reach and jiggling among the stones with a fishing net, it shouldn't be long before you find young Bullhead, Three-spined Stickleback and possibly Stone Loach. The rarer Brook Lamprey is most often seen attached to stones, especially in the spring when they meet in a spawning frenzy.

Bullhead from the River Kennet
Above: Young Bullhead found in the Kennet.

Three Spined Stickleback
Above: Three Spined Stickleback