Fairy Shrimp

Fairy ShrimpI had read about them.  I had seen pictures of them.  I had heard mini-lecture/explanations about them.  But I had never seen them with my own two eyes – alive and swimming in a vernal pool… until now!  I think they might be one of the cutest things I’ve ever seen.

In this photo, the one on the bottom is definitely a female – the dark blob between her thorax and abdomen is a brood pouch containing eggs.  I’m not sure about the other one.  Fairy Shrimp have two sets of antennae.  The second set on males should be extra long as it is used for grasping the female during mating… we can’t really see this indivdual’s other antennae.  Maybe the other is also a female whose brood pouch has already been emptied?  It sort of looks like there is an empty pouch there, doesn’t it?

Biologists say that Fairy Shrimp is an obligate species in vernal pools.  In other words, Fairy Shrimp must breed in temporary, fishless pools that dry up in summer.  Other obligate species are Wood Frogs and Mole Salamanders (Spotted, Marble, Jefferson, and Blue-spotted).  If any of these species are found in a pool, it can be designated a true Vernal Pool.  Vernal Pools have become a focus for many conservationists and there are many programs to locate and catalog them throughout the US.  Click here to read about a Vermont Vernal Pool program, for example.

Fairy Shrimp are fresh water crustaceans that swim with 11 pairs of leaf-like legs.  Here’s 8 seconds of video of the little critters swimming in a pan:

(The other dark wigglers in the pan are mosquito larvae.)

Fairy Shrimp have amazing adaptations for survival, including these noted in Scott Green’s article (link below):

Though the resting period usually varies between 6 to 10 months, eggs have been hatched in a laboratory after 15 years. Eggs have been subjected to temperatures as high as 99C and as low as -190 C and remained viable.

Here are the Fairy Shrimp and mosquito larvae in their natural setting:
How Many Can you See

We visited several vernal pools last Friday and we saw one or two Fairy Shrimp in all.  But one pool – the one that was shrinking most rapidly – that one was just teeming with them!  It was amazing.

Learn more:

9 thoughts on “Fairy Shrimp

  1. Jennifer they were so cool! You’re pictures came out great! What a fun experience that was, I never thought I’d see so many in one pool!!!! SO COOL!!!

  2. Growing up we had a pond next to our house that we called “The Gully”. Every spring, as we rafted and fell in, and got bootfulls (soakers) etc I was always busy catching Fairy shrimp, and watching them for hours swimming in a quart jar.

    They are an inescapable part of the landscape of my childhood memory.

  3. Jennifer,
    Great post! I always learn something from your blog. It was Great seeing the video as well as a photo..to experiece what these critters are all about.
    Thanks for sharing your knowledge.

  4. OMG! Fresh water sea monkeys! That would make them … Pond Monkeys! ^-^ Adorable.. thank you for posting! I think I’ll go check out the area vernal ponds to see if they really are “vernal ponds.”

Leave a Reply

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

WordPress.com Logo

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

Google photo

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

Twitter picture

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

Facebook photo

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

Connecting to %s