Limulus Polyphemus

That is the scientific name for the horseshoe crab, which last night climbed my list of all time favorite animals into the top 10. While the sea cucumber is not all that beautiful to behold, it still wins being that he spits his guts out on predators - I just find that too funny - and you can squirt people with water with them...I know I'm a horrible marine biologist. So apparently I'm very fond of not cute animals because while the horseshoe crab is super crazy cool, he's not all that attractive (sorry horseshoe crabs, you know it's true).

Their coolness makes up for their looks however, and as with most things I now think they are cute because they are so ugly :) So, the reasons horseshoe crabs are now on my top 10 list of coolest animals on the planet:

Reason number 1. They spawn at night on specific beaches, which means to see them you have to plan. I of course am a fan of planning and so I appreciate their fortitude. They have little 'eyes' on the front of their shell that sense UV light. The biggest tides are on the new and full moons and so they can sense the light changes and come up to the beaches on those tides so that their eggs will be laid as far up the beach as they can get them. Here is out walk out, it was gorgeous weather last night:

Reason number 2. Horseshoe crab eggs are food for migrating birds - as you can see in the picture below there were a ton of them last night. One little guy we saw was the red knot, which migrates every year from the southern tip of Argentina to the tundra on the far north of Canada. If the fact that a tiny bird makes a circumpolar trip every year is not amazing enough, I found out last night that they leave Canada before the chicks are ready to leave, and thus the chicks make their trip to Argentina for the first time WITHOUT any bird that has done it before. This is an example of why I am in environmental education - I knew most of this stuff, but when you actually see the bird walking on the sand in front of you and think about how far they flew and are going to fly and that the horseshoe crab eggs are a major reason they can do it...well it's way more amazing than just reading it in a book.

Reason number 3. The females are about twice as big as the males. I just find it kinda funny, and really I appreciate all animals where being fat is a good thing (it's why I love manatees so much). I mean I guess you can't really say that female horseshoe crabs are fat, per se, but they are ginormo. Here are two 'in the act' as it were...it's external fertilization, so it's not really 'the act', but you get the gist.

This is Al showing us that you can tell the males by not only their size, but by the fact that their shell is concave so they can climb on the female. Nature, you are amazing.


Al looks kinda angry here and the one woman was a little out of control with her camera and kept stepping in front of me, but look at the size of this little horseshoe crab lady:

Reason number 4. Their blood is blue. Again, a fact I knew but it's oh so much cooler to see in person than to just know. Instead of Iron which human blood uses to bind oxygen, horseshoe crabs use Copper, so their blood turns blue instead of red when it touches oxygen. Check it out - it's almost as blue as the drill!

Why a drill you may ask - well you have to drill into the carapace to tag them, so you see the little bottle behind the drill? That is betadine. Al would drill into the betadine to clean the drill bit, then drill into the shell, then put the tag in. Pretty cool.

Reason number 5. Horseshoe crabs are more closely related to spiders than they are to crabs. One look inside their shell and you can tell. Personally I'm not a fan of spiders, so the fact that one of my top 10 animals is related to them says a lot about that animal. Horseshoe crabs are 250 million year old spiders so I guess I find that way cooler. You can also see in this picture their gills (at the top of the picture). They are called book gills because they look like pages in a book.


I could go on, but I think 5 reasons is enough to make my point. Our procedure for tagging them was a few people collected the crabs from the surf where they were trying to find themselves a beautiful horseshoe crab woman (we only tagged the males) and put them on the sand (I know they look very sad on their backs, but they were fine)

Then there were other people who would rinse off the crab we were about to tag (you don't need a whole bunch of sand on the shell when you are about to drill a hole in it), bring it to me. I would measure it and hold it for Al to drill it (only the vet gets the drilling job).

Then the girl who was recording the sizes and tag numbers would hand him a tag, he would pop it in the hole (flat white thing where Al's thumb is on the crab) and I'd hand him back to be taken back to the water. We were joking that he would then tell his horseshoe crab friends about this crazy night he had where aliens grabbed him up out of the water and shone lights on him. Poor little guys - thanks for your service to science.

So, all in all it was a beautiful evening. Before we walked back I got a picture with our last guy - he was number 104 (I know, that's a LOT of horseshoe crabs!). They liked to try to grab your fingers and make you let them go but they don't have pinchers that can hurt you like blue crabs do so really unless you are scared of them you just hold on and they push at your hands. It's sad and funny at the same time.
We turned out all our lights and checked out the beautiful sky with no lights around and then walked in the surf where you could see the phosphorecence (it looks like shooting sparks are coming out of your feet when you walk because the phytoplankton light up momentarily when they are disturbed). Then we headed back to Al's house and had some chili his wife Mary made for us and turned into bed around midnight. This, ladies and gents, is why I love my job.