Mollusca · mollusks

Longfin inshore squid

Doryteuthis pealeii

Loliginidae · pencil squidsIUCN: Least Concern
Longfin inshore squid
Photo: Author not stated on Commons · Public domain · Wikimedia Commons · resized

The calamari squid of the Northeast US, caught by bottom trawl.

Fun factIts giant nerve axon helped scientists work out how nerve impulses travel.

Waters
Northeast US, Northwest Atlantic
Depth zone
Coastal shallows & estuaries, Continental shelf
Diet
Small fish & crustaceans
Size
Mantle up to 45 cm

Classification

Mollusca › Cephalopoda › Myopsida › Loliginidae

  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 Myopsida coastal squids
    • Coastal squids whose eyes are covered by a clear membrane
    • Lay egg capsules on the seafloor
  10. Family Loliginidae pencil squids
    • Pencil squids with long, slender bodies and side fins
    • Major fishery species worldwide
  11. Genus Doryteuthis
    • Species in the same genus are very close relatives and often look alike.
  12. Species Doryteuthis pealeii Longfin inshore squid

Closest relatives in the guide