Crayfish Dissection

I'm a little behind in posting about this, but on Thursday we dissected crayfish at Classical Conversations. The actual CC plan calls for only observing the outside of the crayfish, but our director, Kim, thought that was a waste of all those crayfish, so she decided we would dissect them. I offered to lead the dissection for the 3/4 graders (which I teach normally) plus the 5/6 graders, since I figured I could add more for them then their actual teacher, since she isn't a biology person. Kim asked if I could just lead the dissection for the whole co-op, which was just fine with me. Everyone was all together for it. I think it would have been easier if it had been broken up into the older kids and the younger kids, but it went really well. With all the moms there to help, things went really smoothly, even with the younger kids. Everyone (well, most everyone--there were a few pale faces!) thought it was really interesting!
I dug the old lab coat out of the closet in Faith's room, where it has hung since we moved here, untouched. I wasn't sure how "juicy" these crayfish would be, and I didn't want to get stuff all over my sleeves! I started out helping the kids go down the classification of a crayfish, since they have memorized those divisions (the old "King Phillip Came Over For Green Spinach" mnemonic). Then we talked about the outside parts.

Once we actually started dissectiong, I had to run around a lot to make sure people at every table could tell what I was talking about. There is nothing more frustrating than staring at your speciman and not having a clue what you are looking at because nothing looks like what other people are describing! A mom asked me how many crayfish I had dissected, and I told her I really don't know. I think we probably dissected one in high school (does that ring a bell, Amy?!), but I'm not sure. So maybe none. I reread the section in my Vertebrate Zoology book about crayfish and other decapods, and I read some crayfish dissection labs on the internet. The thing is, if you have dissected a lot of different things, you at least kind of know what to expect as far as what parts look like what, even if they don't exactly look like a drawing from a manual! We were able to find and identify all the major organs with no problems at all.

Here is a closeup of a crayfish's gills. My friend Lynnea, and Kim, the director, were both kind enough to take pictures and then email them to me. I had thought about taking my camera but (rightly) decided that I would be running around to busy to take pictures (and would have hands that were too dirty, LOL). So it was nice to have these pictures from friends.

I love this picture of Jonathan! What a little scientist, with his magnifying glass!

This is Nathan and Isaac McC, with Caleb McC leaning in on the left. The older kids really did a great job with everything, and they were especially enthusiastic about the whole thing. Nathan and Luke thought it was "awesome".

Science is supposed to take 30 minutes, and Kim had actually given me 45 minutes, but when I first looked up at the clock, I realized I had almost taken an hour! I apologized, but Kim said all the teachers had said they would rather have the kids stay here, because they were having such a good time and learning so much. Obviously I was having fun, letting time run away with me like that! And it was fun to do something that I really enjoy like that again, and remember that once I had a successful life that didn't revolve around kids, LOL.