Squid Dissection!

On Friday, December 7, our Biology class made some calamari! Just kidding, but on the other hand, we did get to dissect a squid! This was our class' 2nd dissection, and after dissecting the squids, we got to learn more about both the internal and external anatomies of the squid. Before doing this dissection, I usually thought of squid as a delicious seafood delicacy (especially calamari), but after completing this dissection, it was a cool sight to see the actual insides of a squid. Before this lab, we learned about the Phylum Molluska on Thursday. There are 3 classes within the Phylum Molluska: Class Gastropoda, Class Bivalvia, and Class Cephalopoda. The squid is part of the Class Cephalopoda. After learning more about this delicious seafood, I couldn't wait to delve into this dissection. I started this dissection by observing the squid's external anatomy first. I looked at the external parts of the squid, including the funnel, the tentacles and arms, the mantle, the fin, the mouth and the beak. The squid was really slimy, and it didn't have the most pleasant smell either. After observing the squid's external anatomy, it was time to cut this calamari open. I made the incision by using the scissors to cut open the squid from the side of its body. After cutting it open, I used  pins to spread it out so I could get a better view at the internal anatomy. I got a good view of all the internal parts, like the ink sac, stomach, anus, gills, and visceral mass. After opening up and spreading the the squid, I cut off its mouth so I could get a closer look at its beak. The beak overall wasn't very big. After observing the internal parts, me and my partner decided for fun to try and remove the eye, which ended up in disaster. This dissection was a fun and enriching experience since I got to learn more about the squid's anatomies more in depth. It was quite exciting to be able to dissect some calamar- I mean, squid. Speaking of calamari, I can't wait till the next time I have some!

             External Anatomy Questions

1) My squid had 6 arms and 2 tentacles.

2) The purpose of the arms and tentacles differ since both do different tasks. Since the suctions cups are located on the tentacles, they're used to latch onto prey and other surfaces, while the arms are used to move quickly.

3) The 2 arrows pointing down is the direction which the water comes out of the funnel. The squid will move the opposite direction of the arrows. 

4) Two external features that are adaptions for the squid's predatory life are as follows"
1. The suction cups on the tentacles are used to grab prey and latch on to surfaces.
2. The beak is used to pick away at their prey so that it's easier to digest.

5) Two traits that squids share with other mollusks are:
1) Bilateral Symmetry
2) Visceral Mass

Internal Anatomy Questions

1) The squid has one pair of gills (2 gills). The arrow in the picture points to one of them.

2) The ink sac is emptied into the water jet so that the squid can defend itself from its predators. Here is a zoomed in ink sac. 

3) The function of the pen is to support the mantle and help keep the squid steady while swimming.  Here is picture of my fellow classmates squid's pen, since I was unable to pull mine out. 

4) I think the squid excretes its waste through the anus. Here is a zoom in picture of the anus. 

Annelid (Earthworm) dissection!

On Friday, November 30, our Biology class dissected Earthworms! Yes, those icky brown things that look slimy and disgusting. Our class did this so we could learn more about the Earthworm's anatomy. Before doing this dissection, I had no interests in Earthworms at all, and to be honest, I thought dissecting one would be the last thing I would do. But after completing this dissection, I learned so much more about Earthworms. Even as exciting as dissections are, cutting this thing open was no walk in the park. Me and my partner had to be extra careful to not cut any internal organs by accident. After making a cut, a black, slimy liquid came out of the worm, and it did not smell good. Starting our way from the top to the bottom of the worm, we managed to successfully cut open the worm. Prior to this dissection, I had no clue what was inside an Earthworm, but after doing this, I didn't know it would look so fascinating. We were able to see many parts of the worm, including the heart, gizzard and brain. After completing this lab, I learned more valuable information about the Earthworm I didn't know before. This being our first dissection, I thought this was an enriching and exciting experience. As natural decomposers of dead and non-living organisms, the Earthworm is a vital part of the biological world.


1) The name of the Earthworm's pumping organs are the 5 aortic arches, or hearts. (to put it in simpler terms)

The arrow points towards the one of the hearts.

2) The digestive tract begins at the mouth, which is the opening. The food would then get sucked in by the Pharynx and then moves through the Esophagus and into the Crop. The Crop then moistens the food and is then grinded up by the Gizzard. The food then moves to the Large Intestine for more digestion, and then wastes are excreted through the anus. 

The whole worm in its entirety cut open.

3) The Cerebral Ganglion is the part that serves as the Earthworm's brain. The rest of the body is connected through a ventral nerve cord, and at each segment, it is connected to a ganglion which is a cluster of nerves that connects the segments to the brain.

A close up image of a worm brain taken through the microscope lens.

4) The anus and the nephridia are 2 parts of the excretory system that I saw.

Lower half of the worm.

5) By taking a look at the inside of  worm, you can see soil in its digestive system.

The digestive system is visible in this picture.

6) Setae, in latin means "bristle." They help Earthworms attach to surfaces and prevent them from backsliding while they move.

A fun cartoon showing what setae is, since I wasn't able to get
a picture.

7) From the large amounts of soil, the Gizzard grinds down all the food from the Crop (where food is stored) and ingests the distinguished food from the soil.

The upper part of the of the worm shows the digestive system.

8) Beyond segment 32 would be the rest of the digestive system and the worm's digested food.

An up close shot of the lower part of the worm.

9) Since earthworms are hermaphroditic, the mating worms exchange sperm with one another. The sperm would then be stored in until matured. After maturing, the worms clitellium will make a sticky liquid that forms a ring, which now has the fertilized eggs.

An overall picture of the dissected earthworm.