David Shale / View inside the mantle of the deepsea Octopod {Grimpoteuthis discoveryi} Mid-Atlantic Ridge, North Atlantic Ocean

Solvin Zankl / Close up of tentacles and suckers of a Deepsea octopus {Bolitaena pygmaea} Atlantic ocean

David Shale / Deepsea octopus (Benthoctopus sp) mantle showing suckers, deep sea Atlantic oceandeep sea

Georgette Douwma / Common reef / Day octopus hunting for crustaceans and fish, enclosing coral head with arms and webs, using the arm tips to flush out prey into waiting suckers {Octopus cyaneus} Andaman Sea, Thailand

Sergio Hanquet / Common octopus (Octopus vulgaris) female laying eggs, close up of eggs and tentacles. Tenerife, Canary Islands.

Sergio Hanquet / Common octopus (Octopus vulgaris) female laying eggs, tentacles and eye visible amongst eggs. Tenerife, Canary Islands.

Sergio Hanquet / Common octopus (Octopus vulgaris) female laying eggs, close up of eggs and suckers on tentacles. Tenerife, Canary Islands.

Sergio Hanquet / Common octopus (Octopus vulgaris) female, close up of suckers on tentacles. Tenerife, Canary Islands.

Sergio Hanquet / Common octopus (Octopus vulgaris) female, close-up of suction cups on tentacles. Tenerife, Canary Islands.

Magnus Lundgren / Wild Wonders of China / Big blue octopus (Octopus cyanea) , Xiaoliuqiu Island, Taiwan

Pascal Kobeh / Sicklefin devil ray / Chilean devil ray (Mobula tarapacana) with two shark suckers (Remora remora) Azores, Atlantic Ocean.

Pascal Kobeh / Sicklefin devil ray or Chilean devil ray (Mobula tarapacana) with two shark suckers (Remora remora) Azores, Atlantic Ocean.