Forage
How important is this prey in the adult fish's diet?
Snack · Regular · Staple
| Largemouth Bass | Smallmouth Bass | Walleye | Northern Pike | Muskellunge (Muskie) | Trout (Rainbow · Brook · Lake) | Yellow Perch | Crappie | |
|---|---|---|---|---|---|---|---|---|
| Fish | ||||||||
| Small minnows / shiners | Regular — Shiners and baitfish take over from crayfish as the shallows warm in spring | Regular — Shiners and chubs matter everywhere and drive open-water chasing; prey mostly under ¼ body length | Staple — Spottail and emerald shiners are staples nearly everywhere, especially spring: 5–8 cm (2–3 in) | Regular — Shiners fill the gaps; routine meals run 10–30 % of body length | Snack — On the list, but big fish ignore small prey much of the day — routine prey is ¼–⅓ body length | Regular — Around 30–40 cm (12–16 in) big trout shift to minnows · Brook eats them too · Laker prefers pelagic bait | Regular — Past about 20 cm (8 in): minnows and shiners, run down by a loose pack | Staple — The adult calorie base: fatheads, shiners — mostly 2–8 cm (1–3 in), rarely beyond ⅓ own length |
| Yellow perch | Regular — On the stomach-sample list; a regular meal for largemouth in cool northern lakes | Regular — Perch fry and juveniles — a structure-oriented meal ambushed along weed edges and gravel | Staple — One fish above all — hunted exactly when perch eyes fail at dusk | Staple — The staple across its North American range, almost everywhere the two overlap | Regular — Second on the diet leaderboard after suckers; perch bars are a standard pattern | Snack — Laker: a regular meal where the two share a cool northern lake | Regular — Cannibal: past 20 cm (8 in) it treats smaller perch as ordinary prey | Regular — Young yellow perch are part of the northern small-fish base — inside the 2–8 cm (1–3 in) window |
| Sunfish / bluegill | Staple — Bluegill are the signature prey — around cover all summer, year-round on weed lakes | Snack — Eaten where weeds meet rock, but deep-bodied and spiny — prey runs slim, mostly under ¼ body length | Snack — Small bluegills in weedy lakes; it grabs mid-body and swallows slim, soft-rayed fish far more easily | Snack — Eaten but rank low — the sideways grab handles a cylinder far better than a dinner plate | Snack — Spiny, deep-bodied sunfish are demonstrably under-selected relative to their abundance | Hardly ever — Warm weedy-water sunfish and cold-water trout rarely share water — not a meaningful trout food | Snack — Past about 20 cm (8 in), young-of-year sunfish join the menu | Snack — Spring fry buffet — sunfish, bass, and crappie's own fry |
| Ciscoes / whitefish / smelt (pelagic, soft-rayed) | — — Availability and overlapping habitat vary by waterbody; a warm-weed stereotype cannot establish zero use. | Regular — Smelt, ciscoes, and emerald shiners pull it off structure to suspend and chase in open water | Regular — Deep cold lakes: cisco and smelt grow the biggest walleye; November cisco spawn on shallow rock | Staple — Dominate where they exist — oily, soft-rayed, easiest to swallow; spawning-run ciscoes in late fall | Staple — Lakes that have them grow the biggest muskie — cold, fatty, pelagic trophy fuel | Staple — Laker: cisco and smelt are the key — 15–20 kg (33–44 lb) with them, 1.5 kg (3 lb) without | Snack — Jumbos take young smelt where the two share a lake; a grown cisco is bigger than the perch | Hardly ever — Adults are far beyond the 2–8 cm (1–3 in) prey window, and live in colder, deeper water |
| Suckers | Snack — Young suckers are taken at creek mouths and in slow rivers — soft-rayed and easy, seldom abundant | Snack — River fish eat young suckers with chubs and dace; a rarity in lake fish | Regular — Young-of-year white suckers are staple slim prey nearly everywhere, especially in spring | Regular — Dominant where present; spawning-run suckers are part of the late-spring shallow buffet | Staple — Tops the diet leaderboard — documented: a 40 cm (16 in) sucker inside a 110 cm (43 in) muskie | Snack — Laker: young suckers in northern lakes short of ciscoes · stream trout take sucker eggs and fry in spring | Hardly ever — Only newly hatched fry would fit — a grown sucker is bigger than the perch itself | Hardly ever — Far outside the 2–8 cm (1–3 in) small-prey window |
| Shad / alewife | — — Relevant only where these forage species occur; do not transfer a southern seasonal menu to every Canadian lake. | Regular — Alewives in big lakes, shad in reservoirs — pelagic bait that sets off open-water chasing | Regular — Shad in reservoirs; alewife is part of the Great Lakes forage shifts that reshaped its feeding | Snack — Regional: gizzard shad in southern-edge reservoirs and rivers, alewives in Great Lakes bays — taken readily there | Regular — Southern range (Ohio, Kentucky, Tennessee reservoirs): gizzard shad top the menu; absent from northern natural lakes | Regular — Laker: alewife sits on its almost purely fish menu | Snack — Toward the southern range, young shad lift schools off bottom to herd bait | Staple — Threadfin and young gizzard shad in southern reservoirs; young-of-year reach 7–8 cm (3 in) by fall |
| Gobies / sculpins | Snack — Check local presence and access to bottom forage; vegetation use does not exclude feeding on gobies. | Staple — Round gobies dominate adult diets in the Great Lakes; sculpins play the same role in rivers | Regular — A major forage item for Great Lakes walleye since the goby invasion — drag goby colours on bottom | Snack — Sculpins appear in the diet census, nothing more | Snack — Great Lakes–St. Lawrence: turn up in stomachs, mainly of smaller fish — a crumb to a giant | Regular — Big rainbows add sculpins · Laker eats sculpin alongside pelagic bait | Regular — Jumbos past 25–30 cm (10–12 in): gobies now dominate many Great Lakes stomachs; darters, sculpins elsewhere | — |
| Its own kind / other gamefish young | Snack — Even smaller largemouth turn up in stomach samples | Snack — Fry and fingerlings of any bass, its own included, are taken when handy — a minor item | Snack — Cannibalism is well documented and climbs in years when young perch are scarce | Staple — Among the most cannibalistic freshwater fish — smaller pike are a frequent big-pike meal, to ½ own length | Snack — Walleye and bass are minor items — spiny, deep-bodied fish rank low against suckers and perch | Snack — Brook trout eat each other; trout line up to eat other trout's drifting eggs | Regular — Routine: in stunted lakes big perch may be the little ones' main predator | Regular — Routinely eats its own fry — a significant part of the adult diet in crowded, stunted populations |
| Invertebrates | ||||||||
| Crayfish | Regular — Can be important where available; no universal pre-spawn temperature band establishes dietary dominance. | Staple — The signature item — often the largest share of adult diet; molting periods trigger gorging | Snack — A summer side dish off rocky structure — lacks the smallmouth's crayfish obsession | Snack — A minor item, unlike for bass | Snack — Occasional in stomach studies, mostly smaller fish — a trace beside suckers and perch | Snack — Brook: small crayfish · large trout add crayfish as they shift to bigger meals | Regular — Past about 20 cm (8 in): crayfish, soft-shelled especially — jumbo protein off hard bottom | Snack — A small crayfish now and then — but a fish that feeds upward in mid-water meets few |
| Aquatic insects & larvae (mayfly hatches) | Snack — Large insects appear in stomach samples | Regular — Rule early life; adults still sip mayfly hatches — a hex hatch can pull even good fish up | Regular — Hexagenia mayfly hatch shifts feeding wholesale onto larvae — the bite dies for a week or two | Snack — Juvenile food; adults only in fish-poor northern lakes, where invertebrate-eating pike are thin and stunted | Hardly ever — First weeks of life only — young muskie turn to fish fry earlier than almost any gamefish | Staple — Rainbow: 80–90 percent taken underwater — nymphs, larvae, pupae · Brook never leaves insects · Laker: almost purely fish | Staple — Midge and mayfly larvae, bloodworms — the caloric backbone for most perch for life | Regular — Insect larvae year-round; midge larvae are a staple under the ice |
| Zooplankton | Hardly ever — Outgrows plankton in its first summer and never looks back | Hardly ever — Fry only — then insect larvae, then crayfish and fish | Hardly ever — Young only: zooplankton and insect larvae, then fish | Hardly ever — Fry hatch into a zooplankton bloom; adults are fish-eaters | Hardly ever — Fry food for the first weeks only; then fish for life | Snack — Fry food — but lakers in lakes without pelagic baitfish eat plankton for life and stay small | Hardly ever — Fry start on it; by the first fall they graze bottom invertebrates | Staple — A lifelong staple — even for a 35 cm (14 in) slab; most heavily in winter and low light |
| Leeches / worms | Snack — Eaten when found — a nightcrawler or live leech still catches bass — but never a pattern | Snack — Leeches and hellgrammites fill the gap between insects and crayfish — a classic live bait on northern lakes | Regular — Eaten opportunistically, more in summer — once water passes the mid-teens °C (about 60 °F) | Snack — A trace — except in fish-poor northern lakes, where stunted pike are documented living on leeches | Hardly ever — A hunter of large live fish — invertebrates stop mattering in its first weeks | Snack — Brook: worms after rain, leeches — the refuse-nothing generalist | Regular — Aquatic worms and leeches are part of the bottom graze — why worm is the eternal perch bait | Snack — Takes a small worm or leech now and then; plankton and minnows carry the diet |
| Freshwater shrimp / scuds | Hardly ever — Nursery food: young bass pick scuds and grass shrimp from the weeds, then outgrow them | Hardly ever — Feeds the young; adults have moved on to crayfish, gobies and fish | Hardly ever — Young only — an adult turning to invertebrates wants bigger packets: mayfly larvae, leeches | Hardly ever — Adults are fish-eaters; a scud-grazing pike is the sign of a stunted, fish-poor lake | Hardly ever — Never figures — routine prey is ¼–⅓ of its own length | Regular — Rainbow: scuds where they occur, part of the 80–90 percent taken underwater | Staple — Scuds and sowbugs are grazed off weed stems and bottom for life | Regular — Weedy lakes: scuds, and grass shrimp in the South, picked off stems — the rung between plankton and minnows |
| Other | ||||||||
| Frogs / salamanders | Regular — Frogs over mats are a summer menu item; salamanders too — anything struggling on the surface film | Snack — Can be available around grassy banks and shallow cover; smallmouth are not restricted to bare rock or open water. | Snack — Angling lore, not diet science: a fall shoreline bite as leopard frogs return to prairie and Midwest lakes | Snack — Documented, but non-fish prey is a trace — low single digits by weight | Snack — Frogs show up in stomachs — a real but minor garnish | Snack — Brook: salamanders are on the take-everything menu | Hardly ever — A tadpole at most — a frog is far outside a small mouth and a bottom-grazing habit | Hardly ever — Far outside the 2–8 cm (1–3 in) small-prey window |
| Mice / ducklings / snakes | Snack — Mice, snakes, ducklings all show up in stomach studies — the licence behind rodent topwaters | Hardly ever — No real place in the diet — its surface strikes are aimed at baitfish and insects | Hardly ever — A low-light fish hunter working near bottom, not a surface ambusher | Snack — Ducklings, mice, muskrats, small snakes — true stories, rare events | Snack — Ducklings, muskrats, mice, snakes — occasional, yet why oversized topwaters are a core technique | Snack — Large trout take even mice · Brook: mice on the surface at dusk | Hardly ever — Small mouth, bottom-grazing daytime feeder — the surface is not where it looks for food | Hardly ever — A mid-water picker of 2–8 cm (1–3 in) prey — nothing from the bass topwater box |
| Fish eggs | Hardly ever — Not an egg-eater — it is the victim: bluegill are the number-one raiders of its nest | Hardly ever — The one being robbed — gobies, crayfish and sunfish swarm an unguarded bed | Hardly ever — Scatters its own eggs and leaves; it is other fish that eat them | Hardly ever — Hunts the spawning suckers and ciscoes, not what they leave on the gravel | Hardly ever — Never figures in the diet — a hunter of large live fish | Regular — Egg bite twice a year: fall (October–November, mid-latitudes) and spring (April–May); eggs 5–8 mm (about ¼ in) | Regular — Small perch are enthusiastic nest raiders — steal bass eggs and fry, graze pike eggs off the weeds | Hardly ever — Eats fry in open water rather than rooting in nests or gravel |
| Carrion (dead fish) | Snack — Picks up dying shad and dead-sticked baits in cold water — never beats a moving bait when active | Snack — Picks a dying baitfish off bottom in cold water — a moving bait wins whenever fish are active | Snack — Takes a fresh dead minnow on a jig or set line, mostly in cold water — taste decides | Regular — Committed scavenger: fresh-dead fish off bottom, often preferred in cold water — never rotten | Hardly ever — Almost never scavenges — a hunter of live, moving prey | Snack — Laker: willing scavenger — dead cisco or smelt on bottom is a classic ice bait · stream trout: seldom | Snack — Samples anything edible along bottom, dead things included — minnow heads and fish strips are standard baits | Hardly ever — A sight-feeder on small live prey — a lively minnow draws far more bites than a dead one |
Find the staple your lake actually holds and match its size, shape, and depth first — the snacks explain odd lures, not where the fish live.
Levels are judgements drawn from the species notes on this site — tendencies, not guarantees. Local forage, pressure and latitude shift them; the note in each cell says what the level rests on.
Species cheat sheets
Related chapters
- Home-made attractants across species — What a fish eats tells you which flavour to mix