Recommended Free Tools
There are far too many fish species for a useful article to list them all: FishBase recorded 36,535 finfish species in its February 2026 snapshot. This guide explains the main ways to make sense of that diversity, where to look up a particular fish, and how U.S. fish-eating and cooking guidance applies.
What counts as “all fish”?
“All fish” is not a practical single list. The word covers an enormous range of species, and classifications can change as scientists revise taxonomy. The figures here describe finfishes in FishBase, not a timeless count of every organism that might be called fish in every context.
Food guidance uses the word differently: the U.S. Food and Drug Administration (FDA) and Environmental Protection Agency (EPA) use “fish” collectively for fish and shellfish. That consumer-facing usage is broader than the finfish scope of the FishBase species count.
How many kinds of fish are there?
FishBase’s February 2026 snapshot listed 36,535 finfish species, organized across 5,274 genera, 626 families, 84 orders, and 10 classes. These are database figures from that snapshot; taxonomic revisions can change the count.
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →#1 Best Overall
- FIELD GUIDE TO FRESHWATER FISH
FishBase is a reference for taxonomy, biology, trophic ecology, life history, uses, and identification keys. It is useful for exploring fish diversity or looking up a species, but a database count is not the same as a complete, permanent catalogue of every fish.
How do I find out what kind of fish it is?
Start with the fish’s common name if you have one, then check its scientific name, habitat or range, and distinguishing characteristics. A regional field guide can help narrow down a fish seen in a particular place; a maintained database can help verify the name and explore its biology.
Rank #2
| Resource | Best suited to | What it does not replace |
|---|---|---|
| FishBase | Taxonomy, biological information, and identification keys for finfishes. | A region-specific field guide when you need to identify a fish from local appearance and range. |
| FDA Seafood List | Checking acceptable market names for seafood sold in the United States. | A taxonomic database: market naming and biological classification serve different purposes. |
A name on a menu or package may be a market name rather than a scientific identification. For a species-level answer, compare the scientific name and the fish’s range and characteristics instead of relying on the common name alone.
What fish can I eat, and which are lower in mercury?
Mercury levels vary among seafood types, and nearly all fish contain at least traces of methylmercury. The FDA/EPA advice is U.S. guidance, revised in October 2021, and its chart covers listed species and includes geographic qualifiers. It should not be treated as a universal ranking of every fish or as advice for every jurisdiction.
Rank #3
- ENHANCED IDENTIFICATION - Features crystal-clear, full-color photos and detailed descriptions of reef fish, making identification easy and accurate for divers of all levels.
- COMPREHENSIVE COVERAGE - Explore the diverse marine life of Florida, the Caribbean, and the Bahamas with 548 pages of expertly curated content, ensuring you don't miss a single species.
- EXPERT KNOWLEDGE - Authored by renowned marine biologists Paul Humann and Ned DeLoach, providing reliable and up-to-date information on reef fish behavior and habitats.
- DURABLE AND PRACTICAL - Crafted with a water-resistant plastic cover and a convenient 6" x 9" size, this guide is built to withstand the rigors of diving and easy to carry on any dive trip.
- VISUAL LEARNING - Benefit from stunning, full-color illustrations that bring each species to life, aiding in quick recognition and enhancing your understanding of marine ecosystems.
For people covered by the advice—including people who are or may become pregnant, breastfeeding people, and children—the agencies recommend choosing a variety from the chart’s “Best Choices” category. Their advice recommends 8–12 ounces per week from lower-mercury choices during pregnancy and breastfeeding; recommended amounts for children vary by age.
The chart distinguishes some fish by origin. For example, it treats Atlantic tilefish differently from tilefish from the Gulf of Mexico. Check the chart entry and any geographic qualifier rather than assuming a species has one mercury category everywhere.
A fish missing from the chart is not thereby shown to be low in mercury. The FDA/EPA FAQ says a species may be omitted because there is not enough reliable data to include it.
Fish caught by family or friends
Check local fish advisories for the water where the fish was caught. Under FDA/EPA guidance for the covered groups, if there is no advisory, eat only one serving of that catch and no other fish that week. This is not a universal recommendation for every adult or every location.
Best Value
How do I cook fish safely?
The U.S. Department of Agriculture’s Food Safety and Inspection Service recommends cooking fish and shellfish to a minimum internal temperature of 145°F (62.8°C). Use a food thermometer: color and firmness alone are not reliable ways to confirm that fish is safely cooked.
Quick Recap
- Insert the thermometer probe into the thickest portion or center of the fish, following the thermometer’s instructions.
- Check that the internal temperature reaches at least 145°F (62.8°C).
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
