Species: Blue-Ringed Octopus

One of the most intriguing octopuses out there is the Blue-ringed Octopus, a beautiful but deadly cephalopod found in the Pacific Ocean. Here are some fascinating about the Blue-ringed Octopus:

• There are three or four species of blue-ringed octopus; three confirmed and a fourth under study. The three confirmed are the Greater Blue-ringed Octopus, Southern Blue-ringed Octopus, and Blue-lined Octopus.
  
  
• The Blue-ringed Octopus can be found in the Pacific Ocean from Japan to Australia. The Blue-ringed octopus, Hapalochlaena maculosa, can be found only in the temperate waters of southern Australia, from southern Western Australia to eastern Victoria at depths ranging from 0-50 m. Hapalochlaena lunulata can be found in shallow reefs and tide pools from northern Australia to Japan, including Papua New Guinea, Solomon Islands, Philippines, and Indonesia and as far west as Sri Lanka at depths ranging from 0-20 m.
  
  
• The species is named for the bright blue rings it bears, but while resting it is a pale brown to light yellow color, depending on surroundings. The blue rings only "light up" when the animal feels threatened.
  
  
• Blue-ringed Octopuses are born the size of a pea and grow to be about as big as a golf ball.
  
  
• These tiny killers are among the most venomous creatures on the planet. Despite the poison they carry, they are very docile and will camouflage themselves until provoked to attack.
  
  
• The octopus produces venom that contains tetrodotoxin, 5-hydroxytryptamine, hyaluronidase, tyramine, histamine, tryptamine, octopamine, taurine, acetylcholine, and dopamine. The major neurotoxin component of Blue-ringed Octopus venom was originally known as maculotoxin, but was later found to be identical to tetrodotoxin, a neurotoxin which is also found in pufferfish and cone snails. Tetrodotoxin blocks sodium channels, causing motor paralysis and sometimes respiratory arrest leading to cardiac arrest due to a lack of oxygen. The toxin is created by bacteria in the salivary glands of the octopus.
  
  
• There is no known antidote for their poison, which is powerful enough to kill humans. First aid treatment is pressure on the wound and rescue breathing. It is essential, if rescue breathing is required, that it be continued until the victim begins to breathe, which may be some hours. Hospital treatment involves respiratory assistance until the toxin is washed out of the body.
  
  
• Their diet typically consists of small crab and shrimp, but they may also feed on fish if they can catch them. They pounce on their prey, paralyze them with venom and use their beaks to tear off pieces. They then suck out the flesh from the crustacean's exoskeleton.
  
  
• Blue-ringed octopus females lay only one clutch of about fifty eggs in their lifetime towards the end of Autumn. Eggs are laid then incubated underneath the female's arms for approximately six months, and during this process she will not eat. After the eggs hatch, the female dies, and the new offspring will reach maturity and be able to mate by the next year. Like most octopuses, they have a lifespan of approximately two years.
  
  
• The Blue-ringed Octopus lacks an ink sac and has therefore become a common addition to the marine aquarium. Toxicologists strongly disagree with this practice because of the potential danger to people who are unaware of the potentially fatal venom.