Cephalopod intelligence



Cephalopod intelligence has an important comparative aspect in our understanding of intelligence, because it relies on a nervous system fundamentally different from that of vertebrates. The cephalopod class of mollusks, particularly the Coleoidea subclass (cuttlefish, squid and octopuses), 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 and fundamentally different creatures. Classical conditioning of cephalopods has been reported, and one study (Fiorito and Scotto, 1992) even concluded that octopuses practice observational learning. However, the latter idea is strongly disputed, and doubt has been shed on some other reported capabilities as well. In any case, impressive spatial learning capacity, navigational abilities, and predatory techniques remain beyond question.

Predation techniques
Unlike most other molluscs, all cephalopods are active predators (with the possible exception of the bigfin squid). 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.

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.

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.

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. 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.