The San Onofre Tree Octopus (Murphus Where-Aboutsus Unknownus), not to be confused with the only other known tree octopus, the Pacific Northwest Tree Octopus (Octopus paxarbolis), can be found in the trees of the of the San Onofre Creek basin on the west coast of North America. These solitary cephalopods reach an average size 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 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. Reaching out with one of his eight arms, each covered in sensitive suckers, a tree octopus might grab a branch to pull himself along in a form of locomotion called tentaculation; or he 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 he might even be examining some object that caught his attention, manipulating it with his dexterous limbs in order to better know it.
The reproductive cycle of the tree octopus is still linked to its roots in the waters off San Onofre from where it is thought to have originated. Every year, in Spring, tree octopuses leave their homes in the San Onofre Creek basin and migrate towards the shore and, eventually, their spawning grounds in the kelp beds offshore. There, they congregate and find mates. After the male has deposited his sperm, he returns to the trees of the creek basin, 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. The young will spend the six weeks floating in the kelp beds before eventually moving out of the water and beginning their adult lives in the trees of the creek basin.