Reef Octopus El Fanadir North Hurghada Red Sea Egypt
Channel: keepondiving
Date: 28/12/2019

Octopuses and their kin (cuttlefish and squid) stand apart from other invertebrates, having evolved with much larger nervous systems and greater cognitive complexity.
The majority of neurons in an octopus are found in the arms, which can independently taste and touch and also control basic motions without input from the brain.
Octopus brains and vertebrate brains have no common anatomy but support a variety of similar features, including forms of short- and long-term memory, versions of sleep, and the capacities to recognize individual people and explore objects through play.
Octopuses, cuttlefish and squid belong to a class of marine mollusks called cephalopods, along with now extinct creatures called ammonites and belemnites. The fossil record of octopuses remains skimpy. As the only cephalopods without an external or internal shell and no hard parts except for a beak, they do not preserve well. But at some stage during their evolution, they radiated—around 300 species are known at present, including deep-sea as well as reef-dwelling forms. They range from less than an inch in length to the giant Pacific octopus, which weighs in at 100 pounds and spans 20 feet from arm tip to arm tip.