What does the anatomy of squids tell us about the biodiversity of these organisms?

Squid is a unique and interesting animal with elongated bodies. These have two tentacles, eight arms in total and very large eyes. These belong to Phylum Mollusca.

Squids have various adaptation in them. These can change color. They can also create light by using the phenomenon of bioluminescence and can release ink to get rid of any potential threat like sharks etc.

These have around three hearts. Each heart has a specific function to it. While their fins are used to gain oxygen from the water. They also have a very complex nervous system enclosed in a cartilaginous cranium. These invertebrates are assumed to very smart as well.