Squid dissection

On friday my biology 11 class were assigned to dissect a squid. The purpose of this dissection was to find the internal and external parts of a squids internal organs. While we were dissecting me and my partner found how some body parts looked like and how they functioned inside the body. It's better to do hands on things while learning about these kinds of organisms because it gives us a better understanding. We first looked at the external body parts, like the tentacles and arms of our squid. We first separated the tentacles and arms from each other and counted how many of them there were. While looking at the tentacles we notices they had suction cups and not the arms. After observing the external parts we went ahead and dissected the squid. When we opened it up there was fluid and bubbles inside within the organs. All the organs stayed in place and it was easy to label which organ was which.

 External Anatomy Questions

1.) How many arms does your squid have? How many tentacles?

My squid has 8 tentacles and 2 arms

2.) Based on the structure of the arms and the tentacles, describe how their purposes differ. What do the arms do and what do the tentacles do?

The arms: have suckers on the end. The arms of the squid pry open their prey

The tentacles: Are flexible. Equipped with a number of round sucking disks used to grab and hold onto their prey. Used to hold on so that the arms could open the prey up

3.) Draw arrows on the squid to indicate that water comes out of the funnel and the direction that the squid moves.

4.) Name two external features that are adaptions for the squid's predatory life. How do these adaptions help the squid?

- Tentacles(suction cups): The suction cups that are located on the tentacles help the squid catch and hold onto prey. As it as well holds onto walls, rocks and other surfaces

-Waterjet: Squids use their water jets to escape predators and as well attack prey by drawing water into a large cavity into its mantle then rapidly forcing it out

5.) Name two traits that the squid shares with other mollusks.

-Both have a coeloem 

-Both are bilaterally symmetrical 

Internal Anatomy Questions

1.) How many pairs of gills does the squid have?

2 pairs of gills resulting in 2 gills all together

2.) Where does the ink sac empty into and whats its function?

My squid doesn't have an ink sac because it didn't develop fully or it was just too small to find. The ink sac empties into the water jet. The function is to distract and escape from predators acting as a defence system

3.) What is the function of the pen? What would happen if the squid didn't have a pen?

The function of the pen is to stable the squid when swimming. If the squid didn't have a pen it wouldn't hold its shape and would collapse on itself

4.) How do you think wastes exit the squid?

Wastes exit the squid through the anus and the water jet.