Squid by Summer

This week during Biology, we dissected squid. Squid are one of the most developed invertebrates. They are part of the phylum named Mollusca, which means “soft body”. It is also categorized in the class, Cephalopoda, which means “head-footed”. It is listed in these categories because its head is pushed down towards the foot. Octopus, cuttlefish and ancient nautilus are also part of this class.

As you can see, squids have a large mantle, it has eight arms with two longer feeding tentacles which all have suckers on it, a beak and a mouth, a siphon, a large head which has a brain, two large eyes, and three hearts. Squids have gills that help them breathe. They move by squirting water from the mantle to the siphon. This movement is known as jet propulsion. By changing the flow through the siphon, they can change the direction, whether they want to go forward or backwards.

Squid reproduce sexually by releasing eggs into the water. Females will produce 10-50 elongated egg strings, which contain hundreds of eggs in each string, after mating. The squid will die after leaving the spawn on the ground. The egg strings attach to the ground and are left to develop on their own. They should hatch approximately 10 days later.

Questions;

Why are squid important?

What is the purpose of squid?

How big can squid get? How small?

When do they reproduce?