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Fish Identifier

Identify fish by features, habitat, and region

Identify fish species by selecting physical characteristics, habitat type, and geographic region. Narrow down from thousands of species to find your exact match using body shape, fin type, coloration, and size.

100 cm)'}[this.sizeRange] || ''; }, get filtered() { return this.fish.filter(f => { if (this.waterType && f.water_type !== this.waterType && f.water_type !== 'both') return false; if (this.sizeRange === 'small' && f.max_length_cm !== null && f.max_length_cm >= 30) return false; if (this.sizeRange === 'medium' && (f.max_length_cm === null || f.max_length_cm < 30 || f.max_length_cm > 100)) return false; if (this.sizeRange === 'large' && (f.max_length_cm === null || f.max_length_cm <= 100)) return false; if (this.habitat && f.habitat_description) { const h = this.habitat.toLowerCase(); if (!f.habitat_description.toLowerCase().includes(h)) return false; } return true; }); }, reset() { this.step = 1; this.waterType = ''; this.sizeRange = ''; this.habitat = ''; } }">

Identify a Fish

Step 1: Select water type

Step 2: Select size range

Step 3: Select habitat

Filters:

matching fish found

No fish match your criteria. Try adjusting the filters.

About Fish Identifier

Identify fish species by selecting physical characteristics, habitat type, and geographic region. Narrow down from thousands of species to find your exact match using body shape, fin type, coloration, and size.

Identification Free Tool Interactive

Featured Fish

Angelfish

Pterophyllum scalare

Arapaima

Arapaima gigas

Atlantic Bluefin Tuna

Thunnus thynnus

Atlantic Cod

Gadus morhua

Atlantic Halibut

Hippoglossus hippoglossus

Atlantic Herring

Clupea harengus

Atlantic Sailfish

Istiophorus platypterus

Atlantic Salmon

Salmo salar

Barramundi

Lates calcarifer

Betta

Betta splendens

Black Crappie

Pomoxis nigromaculatus

Bluegill

Lepomis macrochirus

Blue Marlin

Makaira nigricans

Bonefish

Albula vulpes

Brook Trout

Salvelinus fontinalis

Brown Trout

Salmo trutta

Channel Catfish

Ictalurus punctatus

Cherry Barb

Puntius titteya

Chinook Salmon

Oncorhynchus tshawytscha

Clownfish

Amphiprion ocellaris
← All Tools

How to Use

  1. 1
    Select physical characteristics

    Choose the body shape, fin type, coloration pattern, and approximate size of the fish you want to identify.

  2. 2
    Narrow by habitat and region

    Select the water type (freshwater, saltwater, brackish) and geographic region where the fish was observed.

  3. 3
    Review matching species

    Browse the filtered results to find your species. Tap any match to see full taxonomy, range maps, and details.

About

Fish identification is a fundamental skill for anglers, marine biologists, aquarium hobbyists, and anyone who encounters fish in the wild. With over 35,000 described species spanning every aquatic habitat on Earth, narrowing down an unknown fish requires a systematic approach that combines observable physical traits with ecological and geographic context.

The Fish Identifier guides you through the same decision tree that ichthyologists use in the field. You start with broad morphological features -- body shape, size class, and fin configuration -- then layer on coloration, habitat type, and geographic region to progressively filter candidates. Body shape alone eliminates entire orders: a laterally compressed disc shape rules out eels and catfish, while an elongated serpentine form rules out sunfish and cichlids. Adding water type (freshwater, saltwater, or brackish) and continent narrows the list further, because most fish families are restricted to one or two of these environments. The tool cross-references your selections against the FishFYI species database to surface the most likely matches, each linked to a full species profile with taxonomy, distribution, diet, and conservation status. Whether you caught something unusual on a fishing trip or spotted an unfamiliar species while snorkeling, systematic feature-based identification is the fastest path to a reliable answer.

FAQ

How do I tell freshwater fish from saltwater fish by appearance?
Freshwater fish tend to have larger, more prominent scales and subdued earth-tone coloration suited to rivers and lakes, while many saltwater species display vivid blues, yellows, and stripes that serve as camouflage or signaling on coral reefs. Body shape also differs: freshwater species are often laterally compressed or torpedo-shaped for current, while reef fish may be disc-shaped or elongated for maneuvering through coral.
What is the most reliable feature for identifying a fish?
Fin ray counts and fin placement are the most taxonomically reliable features because they vary little within a species and are unaffected by age, diet, or water conditions. Dorsal fin spine count, anal fin ray count, and the position of pelvic fins relative to pectoral fins are the three features ichthyologists check first when keying out an unknown specimen in the field.
Can coloration alone identify a fish species?
Color is helpful but unreliable on its own. Many fish change color with age, breeding condition, stress, diet, and even time of day. Juvenile fish often look nothing like adults of the same species, and males in spawning dress may display temporary colors absent the rest of the year. Always combine coloration with body shape, fin structure, and habitat when attempting an identification.
What body shapes are most common in fish?
The five most common body shapes are fusiform (torpedo-shaped, like tuna and mackerel), laterally compressed (flat side-to-side, like sunfish and angelfish), depressed (flat top-to-bottom, like rays and flounder), elongated (eel-like, like moray eels), and globiform (round, like pufferfish). Body shape is closely tied to habitat and swimming style, making it one of the best starting points for narrowing an identification.
How do I distinguish similar-looking species?
When two species look nearly identical, focus on meristic counts (number of dorsal spines, anal rays, lateral line scales), mouth position (terminal, superior, or inferior), barbel presence, and geographic range. Many look-alikes occupy non-overlapping ranges, so knowing where the fish was caught often resolves the ambiguity faster than any single physical trait.