La respiración del pulpo se produce a través de unas branquias interiores, pero no es imposible que un pulpo pueda dejar el agua por un breve periodo. Se cuentan historias de pulpos que han intentado escapar un acuario próximo para invadir otro por la presencia de pescados. No lo tengo confirmado... pero juro que lo he leido.

¿Pero que me dirían de pulpos que vivieran fuera del agua? ¿Oyeron alguna vez hablar de los Pulpos árbol? Una especie que sólo vive en el mar en sus años jóvenes, mientras que posteriormente puede vivir acumulando la humedad de los bosques.
Pues bien voy a dejar un artículo sobre ellos muy divertido, pero antes de liarles con este pulpo anfibio, les desvelo que todo es una inmensa broma que ha llenado páginas y páginas de internet. Así que mi consejo es que no vayan a los bosques a intentar pescar alguno...

The Pacific Northwest tree octopus (Octopus paxarbolis) can be found in the temperate rainforests of the Olympic Peninsula on the west coast of North America. Their habitat lies on the Eastern side of the Olympic mountain range, adjacent to Hood Canal. These solitary cephalopods reach an average size (measured from arm-tip to mantle-tip,) of 30-33 cm. Unlike most other cephalopods, tree octopuses are amphibious, spending only their early life and the period of their mating season in their ancestral aquatic environment. Because of the moistness of the rainforests and specialized skin adaptations, they are able to keep from becoming desiccated for prolonged periods of time, but given the chance they would prefer resting in pooled water.
An intelligent and inquisitive being (it has the largest brain-to-body ratio for any mollusk), the tree octopus explores its arboreal world by both touch and sight. Adaptations its ancestors originally evolved in the three dimensional environment of the sea have been put to good use in the spatially complex maze of the coniferous Olympic rainforests. The challenges and richness of this environment (and the intimate way in which it interacts with it,) may account for the tree octopus's advanced behavioral development. (Some evolutionary theorists suppose that "arboreal adaptation" is what laid the groundwork in primates for the evolution of the human mind.)
Reaching out with one of her eight arms, each covered in sensitive suckers, a tree octopus might grab a branch to pull herself along in a form of locomotion called tentaculation; or she might be preparing to strike at an insect or small vertebrate, such as a frog or rodent, or steal an egg from a bird's nest; or she might even be examining some object that caught her fancy, instinctively desiring to manipulate it with her dexterous limbs (really deserving the title "sensory organs" more than mere "limbs",) in order to better know it.

Tree octopuses have eyesight comparable to humans. Besides allowing them to see their prey and environment, it helps them in inter-octopus relations. Although they are not social animals like us, they display to one-another their emotions through their ability to change the color of their skin: red indicates anger, white fear, while they normally maintain a mottled brown tone to blend in with the background.
The reproductive cycle of the tree octopus is still linked to its roots in the waters of the Puget Sound from where it is thought to have originated. Every year, in Spring, tree octopuses leave their homes in the Olympic National Forest and migrate towards the shore and, eventually, their spawning grounds in Hood Canal. There, they congregate (the only real social time in their lives,) and find mates. After the male has deposited his sperm, he returns to the forests, leaving the female to find an aquatic lair in which to attach her strands of egg-clusters. The female will guard and care for her eggs until they hatch, refusing even to eat, and usually dying from her selflessness. The young will spend the first month or so floating through Hood Canal, Admiralty Inlet, and as far as North Puget Sound before eventually moving out of the water and beginning their adult lives.
Why It's Endangered
Although the tree octopus is not officially listed on the Endangered Species List, we feel that it should be added since its numbers are at a critically low level for its breeding needs. The reasons for this dire situation include: decimation of habitat by logging and suburban encroachment; building of roads that cut off access to the water which it needs for spawning; predation by foreign species such as house cats; and booming populations of its natural predators, including the bald eagle and sasquatch. What few that make it to the Canal are further hampered in their reproduction by the growing problem of pollution from farming and residential run-off. Unless immediate action is taken to protect this species and its habitat, the Pacific Northwest tree octopus will be but a memory.

The possibility of Pacific Northwest tree octopus extinction is not an unwarranted fear. Other tree octopus species -- including the Douglas octopus and the red-ringed madrona sucker -- were once abundant throughout the Cascadia region, but have since gone extinct because of threats similar to those faced by paxarbolis, as well as overharvesting by the now-illegal tree octopus trade.
The history of the tree octopus trade is a sad one. Their voracious appetite for bird plumes having exhausted all the worthy species of that family, the fashionistas moved on to cephalopodic accoutrements during the early 20th Century. Tree octopuses became prized by the fashion industry as ornamental decorations for hats, leading greedy trappers to wipe out whole populations to feed the vanity of the fashionable rich. While fortunately this practice has been outlawed, its effects still reverberate today as these millinery deprivations brought tree octopus numbers below the critical point where even minor environmental change could cause disaster.
How You Can Help
Here are a few things that you can do to help save the Pacific Northwest tree octopus:
Write your representatives to let them know that you are concerned and that you feel the tree octopus should be included on the Endangered Species List and given special protection.
Help build awareness of the tree octopus by telling your friends and co-workers.
Place a tentacle ribbon on your website.
Participate in tree octopus awareness marches. You can demonstrate their plight during the march by having your friends dress up as tree octopuses while you attack them in a lumber jack costume.
Pamphlet your neighborhood. Tentacle ribbons make excellent doorknob hangers.
Join and donate to an organization committed to conservation, such as Greenpeas.
Boycott companies that use non-tree-octopus-safe wood harvesting practices.
Sign the petition! -- nothing activates activity like an Internet petition.
Tree Octopus Research
Please see our Tree Octopus Sightings page for additional photos and behavioral research as they become available. [Updated 2005-04-28]
Links To A Better Tomorrow
More About Cephalopods:
The Cephalopod Page - Scientific information about these wonderful mollusks.
The Octopus News Magazine Online - An online magazine about anything and everything pertaining to octopuses, squids and cephalopods.
2006 Cephalopod International Advisory Council Symposium - To be held in Hobart, Australia. Topic: "Cephalopod Life-cycles: biology, management & conservation."
Other Animals of Interest:
Save The Mountain Walrus - Another endangered Northwest creature that needs our help. (Original site down, link is to Archive.org mirror)
Save The Manhattan Beach Mottled Roach - Save one roach today, that tomorrow we may save millions!
Rock Nest Monster - Known only from its rocky nests and porcelean-like eggs, Cryptogorgo petronidus is so endangered that existential environmentalists wonder if it ever existed at all.
Giant Palouse Earthworm (Driloleirus americanus) - This threatened earthworm is native to the Palouse prairies of Washington and Idaho. They can grow up to three feet in length, are pinkish-white, and smell of lilies.
The Red Crabs of Christmas Island - Once every year, 120 million of these forest crabs migrate en masse from their inland burrows to the sea to spawn. Along the way, over a million are crushed by traffic and many die of dehydration crossing deforested land. The offspring of those that survive then have to contend with super-colonies of yellow crazy ants, introduced to the island by the thoughtless actions of Man.
Conservation Organizations
Greenpeas.org - Greenpeas is working to save the world from humans.
World Conservation Union - An international organization whose mission is "To influence, encourage and assist societies throughout the world to conserve the integrity and diversity of nature and to ensure that any use of natural resources is equitable and ecologically sustainable."
The Wildlife Fund - The WWF works to preserve genetic, species, and ecosystem diversity throughout the world.
UNEP World Conservation Monitoring Centre - An office of the UN that provides information for policy and action to conserve the living world.
People for the Ethical Treatment of Pumpkins - How many pumpkins must be sacrificed every year to decorate our houses and keep our bellies filled with pies before we realize the error of our ways? Too many, it seems!