Class Cephalopoda• Predators specialized for locomotion• Cephalopods include octopuses, squid,

nautiluses and cuttlefish.• Live in marine environments• Only some have a shell• Foot is modified into tentacles, usually

with suckers used to capture prey

Class Cephalopoda• Most cephalopods

have complex eyes • Largest

invertebrate brain– Most intelligent

mollusk (learning & memory)

• Only mollusks with a closed circulatory system

• http://www.iteachbio.com/Marine-Biology/OctopusIntelligence.movhttp://www.iteachbio.com/Marine-Biology/OctopusandCoconutTool.mov

Class Cephalopoda - Nautilus• External shell of

the nautilus is made buoyant by a series of gas chambers.

• 60-90 short, suckerless tentacles

http://www.youtube.com/watch?v=L8qwRCs_7x0

Class Cephalopoda - Cuttlefish• Cuttlefish have a small curved

internal shell, completely enclosed by the mantle.

Class Cephalopoda - Squid

• Squid have a small strip of a shell called a pen, which is enclosed in the mantle.

• Have 8 arms and 2 tentacles (w/ suckers) surrounding mouth

• Giant squid is largest living invertebrate

Class Cephalopoda - Locomotion

• Cephalopods swim by forcing water out of the mantle cavity through a siphon, or funnel, underneath the head

• Funnel can move around animal can move in any direction via jet propulsion

Protection• Color changes affected by

chromatophores (pigment cells)– Allows them to blend into their background

• Squirting out water by jet propulsion helps escape predators

• Octopuses & squids also release an inky substance from an ink sac to distract predators

Feeding

• Cephalopods are carnivores with beak-like jaws surrounded by tentacles •Have a powerful parrot-like beak that is used to tear prey apart.• They also have a powerful radula to scrape away flesh• In some of the octopuses the salivary glands are modified poison glands

Class Cephalopoda - Reproduction

• Cephaolopods are separate sexes .

• Juveniles hatch directly from eggs – no free-swimming larvae.

• One arm of male removes a spermatophore (elongated packet of sperm) from mantle cavity and inserts it into female.

The Mimic Octopus

An Indonesian octopus mimicing a flatfish (above) and a lionfish

(right)

The Mimic Octopus

Color & Morphology Changes for Camouflage

Squid are the largest Cephalopods

Mollusk Nervous System

Gastropods, bivalves, and chitons have gangliaClusters of nerve cells

Ganglia replace the brainCephalopods have a large brain

Sources

http://brainbeau.com/cihs/MarineBiology/Chapter7/Mollusks-Phylum_Mollusca_files/frame.htm

http://www.biologyjunction.com/Molluscs%20revised%20cam.pptx

http://faculty.mwsu.edu/biology/jon.scales/Courses/Zoology/lectoutlines/11_mollusca.ppt