Do perch really eat each other?
Routinely, and it shapes everything about them. A perch past 20 cm (8 in) treats smaller perch as ordinary prey, and in stunted lakes the big fish may be the little ones' main predator. Cannibalism is one of the three reasons schools sort strictly by size (with matched cruising speed and shared diet), and it is a genuine population valve: where big perch are abundant they crop their own young and keep the lake from stunting. It also hands the angler a bait hint — a small perch-pattern jig or blade is not a novelty, it is matching a real menu item everywhere keeping perch as bait is legal (check locally; live perch as bait is prohibited in many places).
The full story
This answer is one piece of a longer lesson — setups, diagrams and the reasoning behind it.
More questions about Diet
- What do yellow perch actually eat?
- Why do tiny baits out-fish big ones so consistently?
- How does a shiner or shad forage base change the game?
- Do perch feed at night at all?
- What do the big jumbos eat that the small fish do not?
- Why is a piece of worm such a reliable perch bait — do perch eat worms and leeches naturally?
- What is simply too big for a perch — frogs, mice, suckers, ciscoes?
Same topic, other species
- What size minnows and shad do crappie prefer? — Crappie
- How big a bait can a largemouth take? — Largemouth Bass
- How big a prey fish can a muskie swallow? — Muskellunge (Muskie)
- How big a prey can a pike really swallow? — Northern Pike
- What is the round goby story in the Great Lakes? — Smallmouth Bass
- What does a stream rainbow actually eat day to day? — Trout (Rainbow · Brook · Lake)
- Why do cisco and smelt lakes grow the biggest walleye? — Walleye