Which Lakes Have the Most Fish Species?

The 25 longest species lists

Pepin Lake currently sits at the top with 47 documented species, a surveyed max depth of 60 ft. Open the lake page for the full list. Counts come from state fisheries surveys matched to each lake — Minnesota DNR LakeFinder is the densest example — not from creel surveys or stocking reports alone.

The full table is lakes with the most species. You can also browse by species (135 of them), or by angling at the best-fishing ranking.

What a long list is actually measuring

A DNR species list records what the survey crews actually caught in gill nets, trap nets, and electrofishing runs — not a census of every minnow in the weeds. The lakes that keep landing near the top of it have four things in common:

• Size and shoreline complexity. More bays, rock, weed, and pelagic water means more niches.
• A depth gradient. Shallow warm bays plus a deep, oxygenated basin can hold bass, walleye, and cisco in the same lake.
• Connected water. Inlets and outlets let river fish commute. Isolated kettle lakes do not.
• Enough oxygen. A high nutrient-and-algae grade helps the coldwater species. It does not, by itself, create habitat diversity.

That last point is visible in the table: 5 of the 9 graded lakes in the top 25 are A or B. The rest are chemically ordinary lakes with a lot of structure. Species richness and the A–F grade answer different questions. Coverage is also uneven: only 3 states publish fisheries survey species lists in enough detail to compare this way, while water-quality grades cover the 49 states and 2 Canadian provinces. A lake in a state without published survey lists is not species-poor — its fish simply have not been counted in a form this table can use.

Eating the catch is a third question. Mercury and PFAS do not care how long the species list is. Mercury, PFAS, and the Fish You Shouldn't Eat is the companion, and each lake with classified fish also has a fishing and water-quality guide path.