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Creature Feature. Camouflaging Octopus . Produce elaborate color patterns and highly complex skin textures Color changes are carried out by small, elastic, pigment-filled sacs, known as chromatophores Each cm 2 of skin may contain hundreds of chromatophores, in up to five colors.
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Produce elaborate color patterns and highly complex skin textures • Color changes are carried out by small, elastic, pigment-filled sacs, known as chromatophores • Each cm2 of skin may contain hundreds of chromatophores, in up to five colors • Each chromatophore is surrounded by a ring of muscle fibers, under control of the large optic lobes of the brain
Blue-ringed Octopus • 3 species • Pacific Ocean from Japan to Australia • Size of a golf ball • Uses its dermal chromatophore cells to camouflage itself until provoked
Venom is powerful enough to kill humans • May bite attackers, including humans, if provoked or stepped on • Venom is a combination of toxins • Major neurotoxin is tetrodotoxin • Causes muscle paralysis • Death results from suffocation • Hunts • Small crabs • Hermit crabs • Shrimp
Mimic Octopus • 2 ft in length • Tropical seas of South East Asia • Not discovered officially until 1998 • Mimics the physical likeness and movements of more than fifteen different species including: • Sea snakes • Sole Fish • Lionfish • Giant crabs, stingrays, flounders, and jellyfish
Uses mimicry for defense and hunting • Able to discern which dangerous sea creature to impersonate to deter current predator • When attacked by territorial damselfishes, it mimics the banded sea snake, a known predator of damselfishes
Video! • http://www.youtube.com/watch?v=ckP8msIgMYE • http://www.youtube.com/watch?v=H8oQBYw6xxc
Pronounced "gooey-duck" is of Native American origin and means "dig deep" Shell ranges from 6-8 in. in length Long siphons can reach 3.5 ft. Weighs 1-3 lbs Feeds on plankton Largest burrowing clam in the world Found along the Northwest coast of the US and Canada (Washington & British Columbia) on sandy/muddy beaches Life expectancy of 146 years (one of the longest living animals)
Reproduction • Broadcast spawners • Females release millions of eggs • Planktonic larvae drift for 2-7 weeks before settling • Sit near the surface of the sand to develop a siphon • They then dig deep into the sand • Only 2% of fertilized eggs reach adulthood • Become immobile and can no longer dig after reaching adulthood
Young geoducks are most susceptible to predators • Shrimp • Crabs • Flounder • Sea stars • Snails • Once the clam buries itself deeper than two feet, it is beyond the reach of virtually all but human predators • Death rate of the adult population is only 2% • However, siphon meat is a prized delicacy
Generally need to excavate a hole up to three feet deep to unearth a geoduck As soon as it is disturbed, the geoduck will retract its siphon downward Be careful not to slice the siphon Must then dig with hangs and gently wiggle the shell free; don't pull on the siphon since it will break Commercial and Recreational Harvest
FUN FACT: The Evergreen State College in Olympia adopted the geoduck as its official mascot, along with the motto Omnia Extares ("Let it all hang out") Geoducks may only be taken with hand-operated instruments It is unlawful to thrust any instrument through the neck of the animal Fine of $75 per unfilled hole May only be harvested during designated shellfish harvesting months (May-September)
Video! • http://www.youtube.com/watch?v=raCUc5A6FHU