Question

why is a squid considered a cephalopod?

A. it has feet attached to its head.
B. it has heads attached to a foot.
C. it has stomachs attached to a foot
D. it has a stomach attached to its head

Answer 1

General:


Class Species No.
Snails (Gastropoda) 43.000
Mussels (Bivalvia) 10.000
Squids (Cephalopoda) 650
Elephant Tusks (Scaphopoda) 600
Neopilina (Tryblidia) 20
Chitons (Placophora) 750
Solenogastres 230
Caudofoveata 120
Molluscs (Mollusca) 55.400
Species number of molluscs. Diagram.
Among the cephalopods there are the largest invertebrates on earth. Their nervous system is developed to a much higher degree than that of other molluscs. The complex behaviour of cephalopods makes them comparable to the vertebrates rather than to other invertebrates.

Schematic body plan of a cuttlefish (Sepia).

The construction of their body shows that cephalopods are molluscs. They have no trace of a skeleton, neither internal nor external. Like that of other molluscs, cephalopods' bodies are divided in head, visceral sac and foot, the mantle (pallium) as a protective coat of the visceral sac.