Goal for last weekend – fairy shrimp!
Neither Keith nor I had ever seen one, but fairy shrimp are an indicator species of vernal pools and the to-do list for the weekend included a property with two well established vernal pools. So….
As discussed in this post, indicator species of a vernal pool include spotted salamanders, wood frogs, and, most importantly, fairy shrimp. However, according to this University of Maine publication, only 5% of their monitored ‘vernal pools’ had recorded fairy shrimp.
The pools we visited this weekend are on a property we are sure to return to multiple times this year. See those small cliffs behind the pond? The property was full of that sort of habitat – parts of the rock is dripping with ground water. Spring ephemerals! Ferns and spleenworts! You will certainly see those cliffs in posts again this summer.
Anyway, back to fairy shrimp. We found some!
The first day out we waded through the pools a bit, carefully stirring up the bottom once in a while. We saw mosquito larvae by the thousands and a frog or two squirted away from us, but nothing we could identify as shrimp. Finally, Keith spied one! After a little catching-fairy-shrimp trial and error (note for next time, we really should have brought a net rather than just a ball jar!), he caught one and I may have yelled. I tend to do that when I see things I define as “awesome” for the first time, and usually those yells are usually, well, not safe for work.
I can’t help it.
This is a bit of macro video of the egg sac being rotated as she moves. If anyone knows why this happens, we’d love to hear it!
So we were excited. We saw three fairy shrimp, and even managed to capture one! We figured the day was a success.
However, back at home that night we discovered that it is quite difficult to distinguish between the Eubranchipus species when you’ve captured a female! They all kinda look the same….
So back out we went the next day in search of a male!
And the next day, for whatever reason, the same vernal pools were swimming with fairy shrimp! And yes, they swim upside-down! The weather was the same. We were out a few hours earlier, but it was not like we were out at 6 AM vs 8 PM. So we unsure why there was such a difference in the numbers one day to the next. Yet another thing we’d love to know if anyone would like to share!
Speaking of pictures, Keith and I each use a Nikon COOLPIX S33 for underwater photographs and video. Keith is really the aquatic plant guy and the water is bit on the chilly side, so he’s the one getting some pretty neat shots with it. Fully waterproof and shockproof, it was my camera of choice for my five year old’s budding photography interest, too!
Armed with a male and time to take some good macro pictures, we headed home.
I’d really only intended to post one male fairy shrimp picture on here, but I’m rather obsessed with this little guy. They have two sets of antennae; the ‘usual’ thin pair on the top of their head, and then a second, larger set that point down, used to grasp the female while mating. As the the females of each species look quite similar, this second set of antennae is important when distinguishing the Eubranchipus species.
How cool is that. Really.
The fairy shrimp are quite transparent, so taking pictures was a little tricky! A flash bouncing around a white bowl gave the best results, and I used two of my three extension tubes for this shot. Shots like these are often trial and error
Animals you can see through. Need I say more. That third dark spot in the middle of his head is naupliar eye, leftover from his larval stage.
And lastly, some calming video of his eleven pairs of legs swimming and swimming and swimming!
We will certainly be hitting up these again as the weather warms up, checking out frog and salamander eggs, and looking for other vernal pool goodies like orb snails, caddisfly larvae and their crazy homes, and whirligig beetles!