Amphioctopus marginatus is known as the Veined Octopus or the Coconut Octopus depending on what the person discussing this animal finds more fascinating; the dark lines forming a color pattern resembling veins or its use of coconuts to make itself a tiny fruit fortress. In majority making a minuscule coconut castle wins the contest of what captures the fancy of most and also shows this invertebrates special abilities which make it an incredibly fascinating creature overall.

The Coconut Octopus is found in the tropical Western Pacific and the Indian Ocean and only reaches the petite size of about six inches when including its arms. Nonetheless, its small size should by no means allow it to be underestimated because this octopus has some extraordinary behavior unique to it alone, tool use. The pint size octopus searches the bottom of the ocean for fallen coconut shells or other discarded invertebrate shells and carries them across the bottom. When the octopus finds its desired resting place and the amount of shells it requires, usually two, it crawls inside of them. The two stacked shells mimics a clam shell in which the Octopus hides inside of as a form a protection. The soft bodied Octopus is very vulnerable to other predators and uses these shells to counteract this.

Although other species of Octopus have been known to hide under foreign objects and other invertebrates use shells as shelter neither of these are classified as tool use. Tool use is defined as retaining an object for future use when it currently does not help the animal in any way, it may even hinder it.  Tool use is not characterized as simply using an object or having a foreign object that is in constant use, like hermit crabs. The Coconut Octopus has been known to carry the shells until it decides to use them thus it is the first known invertebrate to exhibit tool use.

However, tool use is not the only fascinating behavior that the Coconut Octopus displays, this octopus walks. Typically, and more efficiently, octopus species use jet propulsion or sliding across the bottom to move around their environment but this is not the case in regards to this octopus. Only two species of octopus are known to use bipedal motion, locomotion on two feet, and the Coconut Octopus is one of them. The octopus also incorporates this behavior with its coconut or gastropod shell collection. The Coconut Octopus has been observed carrying one or multiple shells with six of its arm while walking over long distances with the remaining two.  When these two actions are united the behavior is known as “stilt walking” for its obvious resemblance to the awkward gait that is present when walking on stilts.

Octopuses have long be proven to be incredibly intelligent animals and are often hypothesized to be the most intelligent invertebrates. However, the Coconut Octopus stretches the limits of previously known behavior. A walking coconut collector and user is an unexpected and new genre of octopus actions. These unique behaviors were discovered after observing only twenty individuals, more dive hours and closer examination of these octopuses could reveal even more surprises in regards to these remarkable invertebrates.

Here is a link to watch the Octopus exhibit all of its unique behaviors!!
http://share11.damn.com/it-looks-like-an-ordinary-shell-but-when-he-gets-closer-my-jaw-dropped-2/

References:
Finn, Julian K., Tom Tregenza, and Mark D. Norman. “Defensive Tool Use in a Coconut-carrying Octopus.” Current Biology 19.23 (2009): R1069-1070. Science Direct. Current Biology. Web. 26 Mar. 2015. <http://www.sciencedirect.com/science/article/pii/S0960982209019149&gt;.