What is the difference between a mollusk and a cephalopod?

The most obvious difference between most cephalopods and other mollusks is the apparent lack of a shell. Octopuses do not have shells at all, while squids have a small internal shell. (Nautiluses, which are found in the South Pacific and Indian oceans, are the only cephalopods with an external shell.

What are the 4 groups of cephalopods?

Cephalopods are members of a class of marine animals that includes octopuses, squid, cuttlefish and nautiluses.

What are the 3 major groups of cephalopods?

Three main clades are typically identified within the Cephalopoda (cladogram B, left): the Ammonoidea (an extinct and shelled clade), Nautiloidea (with only one living shelled genus, Nautilus) and Coleoidea (squids, cuttlefish, octopuses, the Ram’s Horn Squid, the “paper nautilus,” and an extinct clade, the belemnites) …

What are 2 examples of cephalopods?

10 Cephalopod Types Living in Oceans Worldwide

  • Octopus.
  • Squid.
  • Nautilus.
  • Cuttlefish.
  • Vampire Squid.
  • Flamboyant Cuttlefish.
  • Telescope Octopus.
  • Piglet Squid.

Is an octopus a mollusk or a cephalopod?

octopus, plural octopuses or octopi, in general, any eight-armed cephalopod (octopod) mollusk of the order Octopoda. The true octopuses are members of the genus Octopus, a large group of widely distributed shallow-water cephalopods.

Is an octopus a cephalopod?

Octopus. Octopus are the best known of the cephalopods with their charismatic personalities, intelligence, and diversity. There are about 300 different types of octopus currently known, and new types are discovered by scientists relatively often, especially in the deep sea.

Is octopus a cephalopod?

Is a jellyfish a cephalopod?

In fact, jellyfish aren’t closely related to cephalopods at all (and neither are they closely related to comb jellies, another gelatinous sea-going creature). Their closest cousins include corals and anemones. “Corals, anemones, things we call hydroids, sea pens, and jellyfish,” lists Dr. Ames.

Is a squid a cephalopod?

Introduction. A highly intelligent group of ocean dwelling creatures, the living cephalopods include the eight-armed octopuses, the ten-armed squids and cuttlefishes, and the shelled chambered nautiluses.

Is an octopus a mollusk?

Is a snail a cephalopod?

Cephalopods include squid, octopuses, cuttlefish, and chambered nautiluses while gastropods include snails, conchs, abalones, whelks, sea slugs, and garden slugs. Moreover, Cephalopods have a closed circulatory system, while gastropods have an open circulatory system.