Common cuttlefish

Classification

Mollusca › Cephalopoda › Sepiida › Sepiidae

1. Kingdom Animalia animals
   • Many-celled organisms that eat other living things for energy (heterotrophs)
   • Cells have no cell walls
   • Most can move at some stage of life
2. Clade Bilateria bilateral animals
   • Body has a left and right side that mirror each other (bilateral symmetry)
   • Head end with concentrated nerves; three tissue layers
   • Includes about 99% of all living animal species
3. Clade Protostomia protostomes
   • In the embryo, the first opening usually becomes the mouth
   • Main nerve cord runs along the belly (ventral)
   • Includes mollusks, worms, and arthropods
4. Clade Spiralia mollusks, worms & kin
   • Embryos usually divide in a spiral pattern (spiral cleavage)
   • Many have a swimming larva with a band of cilia (trochophore)
   • Includes mollusks and segmented worms
5. Phylum Mollusca mollusks
   • Soft body with a muscular foot and a fold of tissue (mantle) that makes the shell
   • Most have a rasping, tongue-like ribbon of teeth (radula)
   • Includes snails, clams, octopuses, and chitons
6. Class Cephalopoda cephalopods
   • Foot is modified into arms and tentacles around the head
   • Large brains and camera-like eyes
   • Jet propulsion by squirting water through a funnel (siphon)
7. Subclass Coleoidea octopuses, squids & cuttlefish
   • Shell is internal, reduced, or absent
   • Most have an ink sac and color-changing skin cells (chromatophores)
   • Includes octopuses, squids, and cuttlefish
8. Superorder Decapodiformes squids & cuttlefish
   • Ten appendages: eight arms plus two longer feeding tentacles
   • Includes squids, cuttlefish, and bobtail squids
9. Order Sepiida cuttlefish
   • Cuttlefish with a chalky internal shell (cuttlebone) for buoyancy
   • W-shaped pupils and a fin around the whole body
10. Family Sepiidae cuttlefish
    • Masters of camouflage that change color and skin texture in an instant
11. Genus Sepia
    • Species in the same genus are very close relatives and often look alike.
12. Species Sepia officinalis Common cuttlefish

Closest relatives in the guide

• Flamboyant cuttlefish Metasepia pfefferi same family
• Chambered nautilus Nautilus pompilius same class
• Colossal squid Mesonychoteuthis hamiltoni same class
• Common octopus Octopus vulgaris same class
• Dumbo octopus Grimpoteuthis bathynectes same class
• Giant Pacific octopus Enteroctopus dofleini same class
• Giant squid Architeuthis dux same class
• Greater argonaut Argonauta argo same class