Squid and octopus belong to which class?

Squid and octopus belong to which class?

• A. Gastropoda
• B. Bivalvia
• C. Cephalopoda
• D. Polyplacophora

Answer: (C)

In the mollusk family, squid and octopus are classified as cephalopods. The defining feature is a head with arms and tentacles, a beak, and a highly developed nervous system and eyes, along with jet propulsion from a siphon and usually little to no external shell. This combination of traits distinguishes them from other mollusk classes: gastropods (snails and slugs) typically have a single, often coiled shell and a different body plan; bivalves (clams, mussels) have two hinged shells and filter feeding; polyplacophorans (chitons) have eight dorsal plates. Therefore, they belong to Cephalopoda.

In the mollusk family, squid and octopus are classified as cephalopods. The defining feature is a head with arms and tentacles, a beak, and a highly developed nervous system and eyes, along with jet propulsion from a siphon and usually little to no external shell. This combination of traits distinguishes them from other mollusk classes: gastropods (snails and slugs) typically have a single, often coiled shell and a different body plan; bivalves (clams, mussels) have two hinged shells and filter feeding; polyplacophorans (chitons) have eight dorsal plates. Therefore, they belong to Cephalopoda.