Cephalopod intelligence

From Wikipedia, the free encyclopedia

An octopus in a zoo, apparently observing the observer.
An octopus in a zoo, apparently observing the observer.

The cephalopod class of mollusks are considered the most intelligent invertebrates and an important example of advanced cognitive evolution in animals. The scope of cephalopod intelligence is controversial, complicated by the challenges of studying these elusive creatures.

Classical conditioning of cephalopods has been reported, and one study (Fiorito and Scotto, 1992) even concluded that octopuses practice observational learning.[1] However, the latter idea is strongly disputed, and doubt has been shed on some other reported capabilities as well.[2] In any case, impressive spatial learning capacity, navigational abilities, and predatory techniques remain beyond question. Cephalopod intelligence has an important comparative aspect, because it relies on a nervous system fundamentally different from that of vertebrates.[3]

The coleoidea sub-class of the cephalopods includes the orders of cuttlefish, squid and octopuses and it is these which are considered the most intelligent.

Contents

[edit] Examples of intelligence

[edit] Predation techniques

Without exception, and unlike most other molluscs, all cephalopods are active predators. Their requirement to locate and capture their prey has been a probable driving force behind the development of their intelligence, uniquely advanced in their phylum.

The humboldt squid hunts schools of fish, showing extraordinary cooperation and communication in its hunting techniques. This is the first observation of such behaviour in invertebrates.[4]

Although the staple food source of most octopus species, crabs present significant challenges with their powerful pincers and their potential to exhaust the cephalopod's respiration system from a prolonged pursuit. In the face of these challenges, octopuses will instead seek out lobster traps and steal the prize inside. They are also known to climb aboard fishing boats and hide in the containers that hold dead or dying crabs.[5]

[edit] Dexterity

Dexterity, a trait essential for tool use and manipulation is also found in cephalopods. The highly sensitive suction cups and prehensile arms of octopuses, squid, and cuttlefish are just as easily efficient at grasping objects as the human hand.


Octopus opening a container with screw cap

[edit] Communication

Another example of cephalopod intelligence is the communication that takes place between the more social species of squid. Some cephalopods are capable of rapid changes in skin color and pattern through nervous control of chromatophores.[6] This ability almost certainly evolved primarily for camouflage, but squids use color, patterns, and flashing to communicate with one another in various courtship rituals. Caribbean Reef Squid can send one message via color patterns to a squid on their right, while they send another message to a squid on their left.[7][8]

[edit] See also

[edit] References

  1. ^ "What is this octopus thinking?" by Garry Hamilton
  2. ^ Is the octopus really the invertebrate intellect of the sea? by Doug Stewart. In: National Wildlife. Feb/Mar 1997, vol.35 no.2
  3. ^ "Cephalopod intelligence" in The Encyclopedia of Astrobiology, Astronomy, and Spaceflight.
  4. ^ Behold the Humboldt squid. Tim Zimmermann, Outside Magazine, July 2006.
  5. ^ Cousteau, Jacques Yves (1978). Octopus and Squid: The Soft Intelligence
  6. ^ Cloney, R.A. & E. Florey 1968. Ultrastructure of cephalopod chromatophore organs. Z Zellforsch Mikrosk Anat 89: 250-280. PMID 5700268
  7. ^ The Cephalopod Page: Sepioteuthis sepioidea, Caribbean Reef squid
  8. ^ Byrne, R.A., U. Griebel, J.B. Wood & J.A. Mather 2003. Squids say it with skin: a graphic model for skin displays in Caribbean Reef Squid.PDF (3.86 MiB) Berliner Geowissenschaftliche Abhandlungen 3: 29-35.

[edit] External links