Squid Dissection

On Friday December 7 we go to dissect squids in class.  This experiment allowed us to locate major organs inside and outside of the squid and examine the squids features.  In class we had been learning about different mollusks and their body parts and different behaviours.  We had learned about the three main classes of mollusks which include Gastropods, Bivalves and Cephalopods.  The Gastropod class included snails and slugs, the Bivalve class includes clams and oysters and the Cephalopods include octopi and the squid we dissected.  We learned that all mollusks are composed of three parts; the visceral mass, the foot and the mantle.  When we opened up the squids we were able to see all of these parts.  On the outside of the squid we saw the arms that the squids use to take in food and that surround a strong beak that they use to tear their prey.  In class we learned about how squids shoot out a cloud of ink when they feel threatened and when we dissected the squid we found the ink sac and used the ink to write with, almost like a pen.  Dissecting the squid was helpful for me in some ways since it did provide a visual aid for my learning but since not all the squids were completely mature some of the body parts were missing so we couldn't see them.

External Anatomy Questions

1.) Our squid had eight arms and two tentacles.       

2.) The arms have sucking disks on them so they are used to grab their prey.  The long tentacles also have suckers but only on the ends.  They are used to help eat prey.

3.)








4.) Two external features on the squid that are adaptions for the squids predatory life are that it can move quickly through jet propulsion and that it can squirt out dark ink.  Moving quickly is helpful for the squid because it can swim away from predators and escape if they can't swim as fast as it.  Being able to squirt out ink is a helpful adaptation because it can temporarily hide the squid or confuse the predator.






5.) Two general traits that squids share with other mollusks are that they all have trochophore larvae and their body forms are all similar; they all have a foot, shell, mantle cavity and visceral mass.





Internal Anatomy Questions

1.) The squid had one pair of gills.       

2.) The ink sac empties into the funnel and is squirted out when the squid is scared to try and get away from predators.









3.) The pen supports the structure and without it the squid wouldn't be able to hold its shape and it would collapse in on itself.









4.) Waste goes into the anus and then gets emptied into the water jet which releases the waste outside the body.