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North American Fish Identification
Pick the fish. Each page lists the field marks to check, the species it is most often confused with and exactly how to separate them, plus size and range. Photograph the fish flat, in good light, with fins spread; the app names the likely species and these pages confirm it.
How to use these pages
- Start with body shape and tail, then the fins and mouth; most look-alike pairs separate on one or two of those.
- Counts matter: anal fin rays, dorsal spines and scale rows are quoted from agency keys and are the most reliable marks.
- Color is the least reliable mark; it changes with water, season and how long the fish has been out of the water.
- Regulations are by species, so confirm the identification before you keep a fish.
Sunfish and black bass
- How to Identify a White Crappie (Pomoxis annularis)
- Bluegill: ID Marks, Record Size, Eating and Catching
- How to Identify a Pumpkinseed Sunfish (Lepomis gibbosus)
- How to Identify a Redear Sunfish (Lepomis microlophus)
- How to Identify a Largemouth Bass (Micropterus salmoides)
- How to Identify a Smallmouth Bass (Micropterus dolomieu)
- How to Identify a Spotted Bass (Micropterus punctulatus)
- How to Identify a Black Crappie (Pomoxis nigromaculatus)
Catfish and bullheads
Trout
Walleye, perch and pike
Striped and white bass
Gar, bowfin and carp
Inshore saltwater fish
- Sciaenops ocellatus: Red Drum ID, Size, Eating, Rules
- How to Identify a Spotted Seatrout (Cynoscion nebulosus)
- How to Identify a Summer Flounder (Paralichthys dentatus)
- How to Identify a Snook (Centropomus undecimalis)
- How to Identify a Sheepshead (Archosargus probatocephalus)
- How to Identify a Black Drum (Pogonias cromis)
North American Fish Identification
North American Fish Identification
FAQ
What is the fastest way to tell largemouth from smallmouth bass?
Close the mouth and look at where the upper jaw ends: past the back of the eye on a largemouth, at or before it on a smallmouth. The largemouth also has a dark side stripe and a notch between the two parts of the dorsal fin.
How do I tell channel catfish from blue catfish?
Look at the anal fin: rounded outer edge with 24–29 rays on a channel catfish, straight edge with 30–36 rays on a blue catfish. Channel catfish usually show scattered dark spots; blue catfish do not.
Can the app identify a fish from a photo?
It names the likely species from a clear side-on photo. Use the marks on these pages to confirm before you rely on it for regulations.