An octopus's arms give him a distinct advantage in an underwater scuffle, but that's not all they do. His tentacles are strong, flexible and expendable, allowing him to manipulate his environment, navigate with ease and even feed himself. Without his arms (and legs), he wouldn't be able to take care of himself or escape from potential predators.
The octopus's tentacles are strong, and with the rows of suckers on each one, he is able to use them as powerful tools when ensnaring prey and fending off would-be attackers. The arms are long and strong enough to wrap around other animals, while the suckers help him adhere to their flesh or shells. While he typically uses his beak to bite his prey and even infect it with poison, he uses his arms to reel his foe in so he can deal that blow.
Though they may technically be considered legs, two of an octopus's tentacles allow him to more easily navigate his environment. He uses two dedicated tentacles to "walk" along the ocean floor or shove off, giving himself momentum. As for the other six, he can use them -- along with their suckers -- to scale and navigate along underwater surfaces. Because one of his most valuable defense mechanisms is the ability to camouflage himself, staying close to a surface is critical to the octopus's survival.
While octopus arms are breakable, this actually makes them more valuable for the creature's survival, not less. If an octopus becomes trapped or caught in a fight he cannot hope to win, he can tear off one or several tentacles to free the rest of his body, giving him the opportunity to escape. This doesn't leave him crippled, either -- his arms grow back after being ripped off, so he can continue living exactly the way he did before.
An octopus's tentacles are a valuable tool when he's eating, and not just because the suckers on his arms have the ability to taste. His arms are strong enough to rip and crack open shells, allowing him to break through a crustacean's most reliable line of defense and suck out the food inside. Because his arms are so long, strong and flexible, he is also able to reach into underwater crevices, grab small creatures and pull them out to eat them.
Tom Ryan is a freelance writer, editor and English tutor. He graduated from the University of Pittsburgh with a degree in English writing, and has also worked as an arts and entertainment reporter with "The Pitt News" and a public relations and advertising copywriter with the Carnegie Library of Pittsburgh.