cephalopods + more

cephalopods

• squid

• nautilus

• cuttlefish

• octopus

• shell is present, reduced or lost

arms vs. tentacles

• arms:

  • suckers along most of length

• tentacles:

  • suckers only near ends

• octopus = 8 arms

• squid / cuttlefish = 8 arms, 2 tentacles

chronomatophores

• pigment containing and light-reflective cells

• camoflauge and signaling

• ink and venom

nautiloids

• ~2,500 formal spp

• ~9 living spp

• predators and scavengers

octopods

• 8 arms

• no shell

• predators

• beak-like jaw

• mostly shellfish prey

octopod reproduction

• males have one modified arm for sperm transfer

• spermatophores: packets of sperm that can be delivered.

two-spot octopus (cephalopod ex.)

• pacific and indian oceans

giant pacific octopus

• largest and longest lived

• up to 30 ft. long

• 600 lbs +

• diet:

  • shrimp

  • lobster

  • fish

  • sharks

  • birds

vampire squid (vampyroteuthis infernalis)

• deep sea

• temperate + tropical

• neutral bouyancy

• oxygen minimum zone

cuttlefish

• intelligent invertebrates

• cuttlebone:

  • calcified internal shell, aids in bouyancy

• shallow water species

• tentacles retract