Anadromous, Catadromous, Amphidromous, Oceanodromous, or Potamodromous

By Patrick Cooney

Can you say ‘potamodromous‘ and can you guess what it means?

A) Mood disorder from eating too many potatoes.
B) An aquatic dinosaur that crawled across land.
C) A migration of fish entirely in freshwater.

If you pronounced it like ‘poe-tuh-moe-droe-miss’, then you are off to a great start.  But what about the meaning?  For such a strange word, it simply signifies option C, a migration of fish entirely in freshwater.

Many fishes migrate long distances to spawn.   In order to better understand these movements, scientists have classified these migrations into several categories.

Anadromous fish are born in freshwater, then migrate to the ocean as juveniles where they grow into adults before migrating back into freshwater to spawn.

Examples: salmon, smelt, American shad, hickory shad, striped bass, lamprey, gulf sturgeon

Catadromous fish are born in saltwater, then migrate into freshwater as juveniles where they grow into adults before migrating back into the ocean to spawn.

Examples: American eel, European eel, inanga, shortfin eel, longfin eel

Amphidromous fish are born in freshwater/estuaries, then drift into the ocean as larvae before migrating back into freshwater to grow into adults and spawn.

Examples: bigmouth sleeper, mountain mullet, sirajo goby, river goby, torrentfish, Dolly Varden

Potamodromous fish are born in upstream freshwater habitats, then migrate downstream (still in freshwater) as juveniles to grow into adults before migrating back upstream to spawn.

Examples: sicklefin redhorse, lake sturgeon, robust redhorse, flathead catfish

Oceanodromous fish are born near spawning grounds, then drift on ocean currents as larvae before settling as juveniles to grow into adults before migrating back to spawning grounds.

Examples: black grouper, mutton snapper, goliath grouper

Although these different types of migration classifications may be difficult to pronounce, they are important to understand in order to help maintain connectivity between critical habitats.

Considering that many of these fishes use rivers as migration corridors:

1) What impacts might you expect dams to have on the ability of fish to get from one location to another?

2) Might impacts to riverine ecosystems propagate impacts on oceanic ecosystems, and vice versa?

Be sure to check out The Fisheries Blog on Facebook, or check out The Fisheries Blog on Twitter (@FisheriesBlog).

Also check out last week’s post about why fish need floods.

21 Comments Add yours

  1. Don't forget diadromous – see the late R. MacDowell book by same name

  2. Anonymous says:

    flathead catfish = Potadromous? Double check on that…

  3. Wow! After all I got a weblog from where I know
    how to actually obtain useful facts regarding my study and knowledge.

  4. google says:

    This is my first time visit at here and i am genuinely impressed to read
    everthing at one place.

  5. I have learn several good stuff here. Definitely price bookmarking for
    revisiting. I surprise how much attempt you set to
    make this kind of excellent informative site.

    1. nasim says:


  6. I was suggested this website by my cousin. I’m
    not sure whether this post is written by him as
    no one else know such detailed about my difficulty.
    You’re incredible! Thanks!

  7. Osvaldo says:

    Please note references information

  8. odjelua solomon says:

    well done hahaaa my assignments are all here, am done

  9. Brett Kelly says:

    Could have sworn it would have been from eating too many potatoes. Dang. But in all seriousness, nice info, it can be hard to juggle all of the “-adromous” terminology

  10. Jonathan Wright says:

    Does the term “adfluvial” have the same meaning as is being described for “potadromous” here?

  11. Kabira Lawrence says:

    Thanks for the given fish migrations but also talk about other terms like limnondromous.
    Are there other conditions to base on to categorize fish migrations other than spawning?

  12. Kabira Lawrence says:

    Is potandromous similar to potamodromous?

  13. Maria says:

    I loved this article. It was interesting in its geographical information and its human interest. 💦
    I’ve watched eels jump up the water fall where we like to go swimming in the summer. The are cool looking but still creep me out a bit.😬
    wonderful to see these amazing creatures. strange to think that we probably know more about dinosaurs than eels! 🐍 i went to a great talk about them earlier in the year and discovered that they can travel across (wet) land to reach rivers when on migration. 🐍

  14. Kate says:

    I really loved this blog and everyday I do see something new which most of the time adds to my knowledge and motivated me to do things differently. Thanks

  15. Katrina says:

    what happen to the male eel when they reached their adult stage

  16. Max Jordan says:

    Thank you very much for the information, as a researcher for 3 years, I am still gathering information about eels because I am in a conservation project for eels

  17. Esther Enock says:

    This is great!!! Please make some addition i enjoy my study

  18. No exact difference between catadromous anadromous amphidromous oceanosromous

  19. FishwisePro says:

    Great information on eels, you can also check our fish database of more than 102,000 scientific species.

  20. Amalia says:

    Interesting. Thank you for the information!

Please leave a thought provoking reply. We reserve the right to remove comments deemed inappropriate.

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.