Coleoidea
Squids and Octopuses and Cuttlefish
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# of Described Species: First Appearance: Habitats: Benthic and pelagic marine Shapes: Shell-less squid and octopuses Feeding Types: Carnivores |
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# of Described Species: First Appearance: Habitats: Benthic and pelagic marine Shapes: Shell-less squid and octopuses Feeding Types: Carnivores |
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| Coleoids include the familiar squid and ocopus as well as the less well-known cuttlefish. All coleoids have 8-10 suckered or hooked tentacles, a single pair of gills, and an ink sac is often present. The two main groups are Octobrachia, which includes octopuses, paper argonauts the pelagic cirrate octopods (Octopoda) and Vampire Squid (Vampyromorpha). These all have four pairs of tentacles and no internal shell. | The second group is Decabrachia, this includes the rams horn squid (Spirulida), cuttlefish and dumpling squid (Sepioidea), and common squid (Teuthoidea). All have four pairs of non-retractable arms and two pairs of retractable arms (tentacles) and most have an internal shell (reduced to a chitinous pen in squids). The extinct Belemnoidea also belong to this group. |
