Class Cephalopoda [Mollusca]

By: Prof. Dr. Fazal Rehman Shamil | Last updated: February 3, 2024

Class Cephalopoda:

Class Cephalopoda have following characteristics:

Head and Foot Structure:

They possess a distinct head with a complex brain and sensory organs. Their foot is modified into a series of muscular arms or tentacles which are surrounding the mouth.

Tentacles and Arms:

Two elongated tentacles as well as highly mobile arms are found in cephalopods. Arms are usually shorter and eight to ten in number.

Mouth:

They have a beak-like mouth structure made of hard chitinous material. The beak is used to bite and tear prey.

Mantle:

The mantle is a specialized muscular organ that surrounds the visceral mass of cephalopods. It plays an important role in jet propulsion movement that allows these animals to move quickly through the water currents.

Shell

They possess an internal or external shell, with the exception of octopus that lacks a shell entirely.

Camouflage

Cephalopods are well-known for their amazing ability to change their color patterns and texture for camouflage purposes.

Eyes:

They have complex eyes that allow them to perceive a wide range of color patterns.

Intelligent marine animals:

Cephalopods exhibit problem solving skills, learning abilities, and have demonstrated complex behaviors e.g. Octopuses which are known for their problem solving capabilities.

Predatory habits:

They are mainly carnivorous in nature, by feeding on fish and other mollusks.

Reproduction:

These invertebrates can exhibit various matting strategies such as internal fertilization, external fertilization or other mating types of behaviors.

Rapid growth rate:

They have a relatively fast growth rate and short lifespans compared to other mollusks.

Examples of class Cephalopoda:

Scientific NameCommon Name
Loligo spp.Squid
Sepia officinalisCommon Cuttlefish
Octopus vulgarisCommon Octopus
Nautilus pompiliusChambered Nautilus
Architeuthis duxGiant Squid
Argonauta spp.Paper Nautilus
Histioteuthis spp.Cockatoo Squid
Euprymna scolopesHawaiian Bobtail Squid
Sepioteuthis lessonianaBigfin Reef Squid
Rossia spp.Pygmy Squid
Sepiidae spp.Cuttlefish
Ommastrephidae spp.Flying Squid
Dosidicus gigasHumboldt Squid
Todarodes pacificusJapanese Flying Squid
Thaumoctopus mimicusMimic Octopus

List of Mollusca classes with examples 

Phylum Mollusca is classified into seven major classes namely: