Head to head
Bass vs Perch
Both names get used freely for spiny-finned freshwater predators, and the same water can hold fish called bass and fish called perch that are closely related, or barely related at all. Sorting them out means looking at the family rather than the name.
| Bass | Perch | |
|---|---|---|
| Is it one family? | No; a name for many unrelated fish | Yes; the family Percidae |
| Best-known members | Largemouth and smallmouth (black) bass | Yellow perch, European perch, walleye |
| True family of the best-known | Sunfish family (Centrarchidae) | Percidae |
| Native range of the core group | North America (black basses) | Northern Hemisphere |
| Body markings | Dark side stripe or blotches | Vertical bars in many species |
| Dorsal fin | Spiny and soft parts joined or notched | Two clearly separate dorsal fins |
| Egg-laying | Male builds and guards a nest | Sticky egg ribbons or scattered eggs, no care |
| Size range | Up to ~10 kg (largemouth) | Up to ~10 kg (walleye) |
Bass vs Perch: common questions
Is a largemouth bass a kind of perch?
No, despite both being spiny-finned freshwater predators. The largemouth bass, along with the smallmouth and spotted bass, belongs to the sunfish family, Centrarchidae, and is essentially a very large, elongated sunfish. The true perches are the separate family Percidae. The two families are both in the huge order of spiny-rayed fishes and look somewhat alike, with spiny dorsal fins and predatory habits, which is part of why the loose name bass got attached to the sunfish-family species in the first place. In Europe, confusingly, the fish called perch really is a percid, so a European angler and an American angler using the words perch and bass are often talking about fish in different families.
What is the difference between a perch and a walleye?
They are in the same family, and a walleye is essentially a large, elongated, low-light-adapted relative of the yellow perch. The yellow perch is a smaller shoaling fish, usually 15 to 30 cm, with a rounder body and bold dark bars, active by day. The walleye grows to 50 to 80 cm or more, is longer and more streamlined, has a brassy, mottled body without strong bars, prominent canine teeth, and large silvery eyes with a reflective layer that lets it hunt in dim and murky water. The European equivalent of the walleye is the very similar zander, or pikeperch. All three are percids.
Why does the same fish get called both bass and perch in different places?
Because both names were spread by English speakers who applied familiar words to whatever local fish looked and behaved the part. When settlers reached North America they called the large sunfish-family predators bass, after the European fish of that name, and called various other spiny fish perch. Meanwhile in Britain the native percid kept the name perch, and bass came to mean the coastal temperate bass. Australians, South Africans, and others added their own uses. The result is that bass and perch are folk categories layered over several real fish families, and the only way to know what a given bass or perch actually is, is to identify the species.