Cephalopods and Phylum Mollusca Overview

These flashcards summarize key concepts related to cephalopods and the broader classification of Mollusca as detailed in the lecture notes.

What are the key characteristics of the Phylum Mollusca?

Includes clams, snails, octopus, squid; approximately 100,000 living species and 70,000 fossil forms.

What are the seven classes of Mollusca?

Aplacophora, Monoplacophora, Polyplacophora, Scaphopoda, Gastropoda, Bivalvia, Cephalopoda.

What distinguishes the Mollusca's circulatory system?

They have an open circulatory system with a hemocoel and a heart composed of two atria and a ventricle.

Describe the main features of the molluscan mantle.

It is an epithelium covering the body, secreting a calcareous shell or spicules, consisting of three layers: periostracum, prismatic, and nacreous.

What is the function of the radula in Mollusca?

The radula is a cuticular band of teeth used for feeding.

What type of nervous system do Mollusca exhibit?

They have a well-developed nervous system with ganglia and nerves to various body parts.

What type of larva do molluscs develop from?

They develop from trochophore and veliger larva.

Which class of Mollusca is known for its elaborate shell and complex body structure?

The class Cephalopoda is known for its elaborate structure.

What class does the common chiton belong to?

The common chiton belongs to the class Polyplacophora.

What are the two subclasses of Cephalopods?

Nautiloidea and Coleoidea.