• Having trouble identifying a fish? It's okay! Fishes are mind-bogglingly diverse. I mean, seriously, there are over 34,000 extant (living) species and more are being discovered annually.

Tip #1: Use Your Smartphone! (if you have one available)


This is the age of technology, so you should be readily available to access the internet before, during or after you need to identify a fish. Look up your local government's natural resource or fish and wildlife department (usually a simple insert of your state followed by "DNR" or "F&W" or "Fishing" does the trick. Example: "CA F&W"); if you are a United States citizen, some of your tax money went into projects where biologists created resources for you to see the common species within local waters. They usually have detailed illustrations and descriptions FREELY available for reference.

Tip #2: The Mnemonic


Ever heard of a mnemonic? Sure you have. Remember ROYGBIV? The acronym for the hues of the rainbow that we had to learn in school. It's much easier to remember all 7 of those colors when they are all simplified into a single acronym. Then it becomes even easier to remember after turning ROYGBIV into a story (we have great capability of memorizing stories because we are neurobiologically wired that way). Check out this mnemonic sentence example for ROYGBIV:

  • Example: Richard of York gave battle in vain.

Now we just look at the first letter of every word in our little story. Richard-red, of-orange, York-yellow, gave-green, battle-blue, in-indigo, and vain-violet.

EASY! Okay, now for the fishes...

Koaw's Mnemonic for Identifying Fishes - BAMFAD -

  1. BAMFAD! (That's the acronym - easy to say, right?)
  2. Now the mnemonic part - Being a master fish-analyzing detective!  B-A-M-F-A-D!
  3. Okay, say BAMFAD a couple more times...BAMFAD! BAMFAD!
  4. The Key: Being-body, a-appearance, master-mouth, fish-fins, analyzing-area, detective-demeanor.
  5. Time to break it down.
  • B is for BODY: The general shape of the fish is the best place to start. Is it rounded, elongated, boxy, snake-like? Then think about the size. Is it as big as a car? Or is the fish the size of a pebble?
  • A is for APPEARANCE: Look for standout coloration, patterns, and markings. Are there stripes? If so, what direction are they oriented? Is there an eyespot (a fake eye)?
  • M is for MOUTH: The relative positions of the upper and lower jaws to one another are big clues. Does the fish have a lower jaw extending out farther than its upper jaw? Are there noticeable teeth? (Check out this chart to see common mouth-types).
  • F is for FINS: Find all the fins you can. Notice the position of the pelvic and pectoral fins. How many dorsal fins are there? What does the tailfin (caudal fin) look like?
  • A is for AREA: Habitat. Where are you seeing this fish? In freshwater, saltwater, brackish water? Are you near a fast river, large lake, coral reef, open ocean or some other body of water?
  • D is for DEMEANOR: What is the fish doing?! Is it burrowed in the sand poking its head out? Is it swimming with hundreds of others? Is it chasing tuna?

Tip #3: Remember a Few Distinguishing Things

If you can remember 1 or 2 distinguishing features about the body, appearance, and mouth, then you will probably be able to identify your fish. Well, at least be able to narrow it down to the correct family or genus.

Tip #4: Variation Exists within Populations!

Even within the same species, specimens can vary greatly in appearance. Why?

  • Age: From egg to larva to fingerling to maturity, a fish can vary tremendously in appearance over the course of life. Just look at the difference between the adult emperor angelfish (with the yellow tail and horizontal stripes) and the juvenile.
  • Sexual Dimorphism: Just as human females and males have distinct differences in appearance and sexual organs, many fishes similarly vary in shape, color, markings, and behavior depending on sex.
  • Genes: Just like humans vary in appearance, so do fishes!