Cephalopods

Cephalopods Tentacles grow from head, shell varies throughout the class

SUPPORT STRUCTURE Nautilus – light chambered shell Squid – thin internal shell Cuttlefish – thick bone-like structure Octopus – no support structure

Cuttlefish Squid-like, fast swimmers

Cuttlefish

Cuttlefish

Cuttlefish

Octopus Rarely swims, crawls on 8 arms Lives in holes, crevices, and burrows Nocturnal hunters, squirt ink as defense

Giant Pacific Octopus

Squid Very active swimmers Commonly found in schools Aggressive predators

Arrow squid

Opalescent Squid

Nautilus Slow swimmers Can have up to 90 arms

Chambered Nautilus

CHAMBERED NAUTILUS

Intelligence Octopus is the smartest known invertebrate – can learn from past experiences

Size Giant squid is the largest living invertebrate – up to 50 feet long

In September of 2005 Japanese scientists shot the first photos ever taken of a living giant squid in its natural environment – Northern Pacific Ocean. Measured roughly 25 feet long

Mouth Located in the center of the tentacles, have a beak, venomous glands, radula

Ringed octopus has venom that can be fatal to humans

Siphon Propels them, runs water and oxygen over gills, eliminates wastes, releases gametes, releases ink

Chambered nautilus Can fill or empty their chambers with water to control buoyancy