The cephalopods

The CephalopodsPhylum Mollusca

Class Cephalopoda– “Head Foot”

-Head and arms are distinguishing features-Many have ink-Many have beaks-Many have unique methods of camouflage

Examples:• Octopus – Head with 8 arms;

all venomous, only one deadly to humans, most intelligent invertebrate

• Squid – Longer, slender head with 8 arms & 2 tentacles, largest invertebrate

• Nautilus – only Cephalopod with an external shell

• Cuttlefish – internal shell (cuttlebone)

Anatomy• Exclusively marine• Prominent head• Arms for feeding, propulsion, reproduction• Many can expel ink to discourage predators• Very well developed eyes• Gills for respiration• Jet propulsion by squeezing body together quickly

and jetting in the opposite direction• Bilateral symmetry

Habitat• Benthic– Highly Motile– Epifauna –live on

seafloor– Have adapted to

almost every marine environment in the world

Feeding

-Most are predators using arms, tentacles, suckers to capture then beak to rip prey apart

Cephalopod Feeding cont. – Beaks

Cephalopod Reproduction

-Separate sexes-External fertilization and development-Distinct egg cases-Most types die after reproduction (many only living 1-2 years)

Octopus Camouflagehttp://www.youtube.com/watch?v=t-LTWFnGmeg&feature=endscreen Andhttp://www.youtube.com/watch?v=eS-USrwuUfA

Cephalopod Internal Anatomy