The Blue-Ringed Octopus of Australia

Like other octopuses, the blue- ring has many small suckers shaped liked cups on the arms which help it to pick up objects (Blue-ring, 2004). Its diet consists of crustaceans, particularly crabs, and molluscs. A larger species, the H. lunulata, which measures about 5" across the body, is found between the Philippines and Indonesia, as well as from Papua New Guinea to Vanuatu (Bluering, 2004). Here it inhabits the coral reefs and hunts for crustaceans and smaller molluscs.

The blue-ringed octopus has two large salivary glands (venom glands) situated above its brain (Blue-ring, 2004). A duct leads through the brain into the mouthparts which terminate in a small, parrot-like beak found at the junction of its eight arms. When hunting for crabs, the octopus swims over its prey and sprays its poisonous saliva into the sea around it. The crab absorbs the poison and becomes para

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tetrodotoxin, which is found in the pufferfish (Blue Ringed Octopus, 2004). It is the only form of tetrodotoxin to be found as a venom. It is not made by the octopus itself, but by symbiotic bacteria inhabiting the salivary glands of the octopus (Bluering, 2004). These bacteria are transferred from mother to young, so that even the eggs already contain sufficient amounts of venom to be harmful. The venom exists as a cocktail of several poisons which are species specific, but the major portion of the poisonous mix is the nerve toxin tetrodotoxin. The effects of maculovenom are therefore the same as those of tetrodotoxin. Tetrodotoxin is a potent marine neurotoxin, named after the fish with which it is most commonly associated - the Teraodontiformes, the tetradon pufferfish (Johnson, 2002). Tetrodotoxin (TTX) specifically blocks voltage-gated sodium channels on the surface of nerve membranes. The molecule of TTX consists of a positively charged guanidinium group and a pyrimidine ring with five additional fused ring systems which contain hydroxyl groups which help stabilize the TTX-sodium channel binding complex at the aqueous interface. The TTX-Na channel binding site is extremely tight (Kd=10-10 nM). TTX mimics the hydr
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Some common words found in the essay are:
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Approximate Word count = 1918
Approximate Pages = 8 (250 words per page)