| Share


Class Cephalopoda

This class contains the cephalopods, animals commonly known as squid, cuttlefish, octopus, and nautilus. The giant squid is the largest of all mollusks. Most cephalopods are highly adapted for swimming. The body mass is very tall. There is no foot; the lower part of the body wall is drawn out to form a ring of arms, or tentacles, around the head. Among living cephalopods, only the nautilus (subclass Nautiloidea) has a complete external shell; extinct members of the subclass and the extinct ammonites (subclass Ammonoidea) had similar spiral shells. Members of the subclass Coleoidea (the squid, cuttlefish, and octopus), have an internal shell or no shell at all.

All cephalopods are carnivorous and possess a radula and powerful beaks. The nervous system and the sense of vision are highly developed. In most cephalopods the sexes are separate and reproduction requires copulation. Fertilization may occur inside or outside the mantle cavity. Cephalopods are worldwide in distribution and are found in all depths of the ocean. They are an important food staple for many animals, including humans.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on Mollusca Class Cephalopoda from Infoplease:

  • Mollusca: Class Cephalopoda - Class Cephalopoda This class contains the cephalopods, animals commonly known as squid, cuttlefish, ...
  • ammonite - ammonite ammonite , one of a type of extinct marine cephalopod mollusk, related to the nautilus and ...
  • paper nautilus - paper nautilus paper nautilus, pelagic, surface-dwelling cephalopod mollusk of the genus Argonauta. ...
  • nautilus, in zoology - nautilus nautilus, cephalopodmollusk belonging to the sole surviving genus (Nautilus) of a subclass ...
  • squid - squid squid, carnivorous marine cephalopod mollusk. The squid is one of the most highly developed ...

See more Encyclopedia articles on: Zoology: Invertebrates

Premium Partner Content
HighBeam Research
Documents Images and Maps Reference
(from Newspapers, Magazines, Journals, Newswires, Transcripts and Books)

Research our extensive archive of more than 80 million articles from 6,500 publications.

Additional search results provided by HighBeam Research, LLC. © Copyright 2005. All rights reserved.

24 X 7

Private Tutor

Click Here for Details
24 x 7 Tutor Availability
Unlimited Online Tutoring
1-on-1 Tutoring