Introducing: Horseshoe Crabs in the Classroom, Take 2


During the 2011/2012 school year, we had a program called Horseshoe Crabs in the Classroom at our elementary school. This program is offered through the Maryland Department of Natural Resources and it's a great idea for a number of reasons - letting kids learn about these incredible pre-dinosaur animals while, maybe, helping add a few more of these amazing animals to the Chesapeake Bay.

Last year, we ended up with no live horseshoe crabs (HSC) and I think this was because of over-zealousness on my part for ridding the aquarium of an unwanted fungus or at least what I thought was fungus. The 4th graders, though, were very enthusiastic and they learned a lot about the critters even though they never saw a live one in their classroom. Sigh.

This year, though, now that the teacher (me) is a bit more experienced, I think we'll have better luck. So here's Take 2...

Tuesday, July 10, 2012

July 10 - Part 2

So, I thought it might be fun to do a little video of what the crabs and the tank are looking like now so here goes...

Today I could see 2 different forms of horseshoe crabs larvae - the young ones still don't have tails and swim a lot in the morning. The second type form looks almost like the sand. Pretty good camouflage. The first video shows the two different ages in the same spoon. I say in the video that the larger ones might be ready to molt - but maybe what has happened is that they've already molted and their shells aren't completely hardened yet because you can still see through the shell. I'm just guessing here. Or maybe their digestive system (guts) aren't fully formed yet and that's why they're semi-transparent.


The second video you'll have to look at pretty carefully to see any movement in the sand - like I said, they are well camouflaged and active.



And now for the latest photo: this larvae looks different from the earlier one - the formation of a little tail (maybe) and the lack of a pinkish attached yolk. It's a faint photo and I tried to improve the contrast but it's not the greatest.

It looks a bit more formed than the other day - you can kind of see the tail forming? Maybe? I'm thinking there's no yolk meaning that it has gotten to the point of needing food so I'm glad I added brine shrimp today. This one was on his/her back so you can't see the eyes. 

And that's what the tank and the crabs look like now - July 10, 2012


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