Last modified on September 26, 2018, at 18:53


Scientific classification
Kingdom Information
Kingdom Animalia
Phylum Information
Phylum Mollusca
Class Information
Class Cephalopoda
Sub-class Coleoidea
Order Information
Superorder Octopodiformes
Order Octopoda
Population statistics

An octopus is a cephalopod mollusc in the order Octopoda in its broadest sense, but also will refer more narrowly to groups of organisms within the family Octopodidae, or even more specifically the genus Octopus.[1]


Generally less actively swimming than fellow cephalopods squid and cuttlefish, an octopus has eight flexible suckered arms, used for grasping rocks and prey as well as propelling the octopus. These are often inaccurately referred to as "tentacles", but in fact that term refers specifically to two longer extremities which cuttlefish and squid have at the front of their bodies but octopuses do not. To move, it may pull itself over the sea bed with its arms, but when in a hurry, it shoots a jet of water out of its body, thrusting it through the water.

Octopuses use chromatophores to perfectly camouflage themselves against their background. When threatened, they can eject a cloud of ink to mask their escape. They can compress their bodies to fit through minute apertures.


Octopuses, after engulfing prey in their arms, inject it with venom. Some, such as the blue-ringed octopus of Australia, are highly venomous and are capable of killing a man with their bite.

Octopuses as food

Octopus is a popular seafood, especially in Mediterranean and Oriental cuisines, though it must be cooked carefully to avoid the flesh becoming rubbery.

Octopuses in popular culture

The Octopus is also the name of novel by Frank Norris.


While "octopi" is the popularly used plural form of "octopus" and is sometimes listed as such in dictionaries,[2] it is incorrect [3] because the word does not derive from Latin; the strictly accepted plurals are "octopuses" and "octopodes". Scholars working with cephalopods have settled on the usage of "octopuses" as plural for "octopus" in the narrow sense referring to species within the family Octopodidae[4] and "octopods" the plural to refer more broadly to all species within the order Octopoda.[5]


  1. Brusca, RC & Brusca GJ (2002). Invertebrates, 2 ed. Sinauer Associates Incorporated, Sunderland, MA.
    • Mather, JA & Anderson, RC (1993) Personalities of octopuses (Octopus rubescens). Journal of Comparative Psychology 107:336-340
    • Villanueva, R; Nozias, C & Boletzky, SV (1995) The planktonic life of octopuses. Nature 377:107
    • Sumbre, G; Fiorito, G; Flash, T & Hochner,B (2006) Octopuses use a human-like strategy to control precise point-to-point arm movements. Current Biology 16:767-772
    • Voight, JR (1997) Cladistic analysis of the octopods based on anatomical characteristics. Journal of Molluscan Studies 63:311-325
    • Lewy, Z (1996) Octopods; nude ammonoids that survived the Cretaceous-Tertiary boundry mass extinction. Geology 24:627-630
    • Kubodera, T & Okutani, T (2004) Eledonine octopods from the Southern Ocean: systematics and distribution. Antarctic Science 6:205-214