That is what we dissected in Biology today. 😀
To see what else we are doing for this module, please go to the Apologia Biology page and scroll down to Module 12.
Look at this critter. Isn’t it the cutest thing you ever saw?! God did an awesome job with the Crayfish.
As always we begin the experiment by just observing the specimen.
Did you know that the antennules are used for sense of touch, taste, and balance? The most interesting part about the balance, is the statocyst that is located at the base of the antennules. Inside this shaft, there is a grain of sand called the statolith. This statolith shifts if the mudbug is knocked off balance. The hairs in the shaft sense this and then tells the brain, “Hey buddy you’re upside down. Turn over, will ya!” How totally cool is that!?
Each student must draw and label their specimens. This is our second dissecting, which has more organs than the one before and already the students are complaining about the amount of drawing they have to do. Since each specimen has more specific organs than the last one, I don’t know what they will say by the time we get to the pig.
The next step was to determine the sex of the crayfish. As with almost all creatures, you have to turn them over to tell the difference. 🙂 Males two front swimmerets are longer than the rest, while in females the two front swimmerets are shorter. Out of four crayfish we had two males and two females.
By this time the students were getting antsy to cut it open. Half of the cephalothorax was removed to see the gills. This part wasn’t easy because the hard exoskeleton.
Crayfish have an open circulatory system, so the body cavities are filled with blood to transport oxygen and remove carbon dioxide. The Gills take in oxygen from the water, into the blood, and release carbon dioxide from the blood.
I don’t know what this picture is, but doesn’t it look interesting?
After all organs were identified and examined, the students decided to just rip the critter apart. This is where we started talking about how you are suppose to eat them. This student, ripped the tail off to show us that you were to eat the muscle out of the tail, then suck the brains out of the head. I’ll eat the meat out of the tail (not a specimen), but I won’t eat the brain. Nasty.
Go here to see a video on how to eat these things.
If you really want to know more about how to fix Crayfish for dinner, just Google Crayfish recipes and you’ll get more links than you think possible.
Want to know what else we have been doing, just click on the Apologia Biology button at the top of the blog.