This huge 16 lb, 4 oz. brown trout was caught by John Chester in southern England.  The fish was caught incidentally after the season had closed, and was released back into the water.  The trout was reported as being the biggest brown caught in the area in over 100 years.

Weston Mercury article

Wes Case of Ashton, Idaho, landed a 37 inch, 27.3 pound brown trout in eastern Idaho’s Ashton Reservoir.  The trout broke the Idaho state record by almost a pound, and was a much larger fish than biologists ever expected to come out of the reservoir. 

Fisheries biologist Dan Garren estimated the trout at 10-11 years old, using otiliths (ear bones) to calculate age. 

The fish likely grew fast early, and switched its diet from insects to fish at a relatively young age.  For a fish to grow that large, it has to feed on lots of other fish, which have a much higher energy content than do insects.

Read more about the new Idaho state record brown trout