Nautilus Morphology• Head, tentacles, foot, and

hyponome (organ that shoots jets of water to help it move) near the aperture of the body chamber.

• Visceral mass containing other vital organs is situated to the rear of the body chamber.

• Chambers of air help the nautilus move up and down and each chamber is separated by a sheet of calcite called a septum.

Nautilus Morphology

Squids• Can confuse predator by

secreting clouds of ink from internal ink sacs.

• Some can even eject a “dummy” ink that takes the rough form of its size and shape.

• At least one known species of squid that lives below the photic zone produces a sparkling luminous ink.

• Squid can grow very large. Giant squid have been recorded at lengths of almost 60 feet!.

Squid Reproduction• Sex and reproduction in

cephalopods is in many ways quite different than in other molluscs.

• First, sexes are separate and mating usually includes a courtship that often involves elaborate color changes.

• This is followed by the transfer of a spermatophore (sperm packet) by a male to a female through her mantle opening.

• Then a female lays the eggs.

Changing Color• Cephalopods have an

amazing ability to change color very rapidly.

• They use numerous pigment-filled bags, called chromatophores.

• Chromatophores are found in the skin, and expand and contract to reveal or conceal small dots of color.

• Use for courtship, camouflage, communication, or as a warning to predators.

Squid Morphology• Squid have 10 tentacles

• An internal ink sac/gland

• Thin, internal shell

• Beak for tearing flesh.

Octopuses• The most intelligent mollusk

• About as smart as a puppy and with better eyesight.

• Live in the intertidal and subtidal region of rocky coastlines.

• Can memorize the location of hiding places, escape holes, and hunting locations

• Octopuses in captivity have even been known to play with toys and recognize their keepers.

Octopus Morphology• 8 tentacles

• Large brain

• Note the beak and ink sac