Life of Sea | Southern Blue-ringed Octopus(Hapalochlaena maculosa) | Southern Blue-ringed Octopus or Lesser Blue-ringed Octopus is marine that should be avoided to touch. It one of the most venomous animal in the world. Blue-ringed Octopus gets it names from the bright blue rings that appear when the blue-ringed octopus is alarmed. Additionally, when alarmed, Southern Blue-ringed Octopus shows small blue rings (hence the name "lesser"). Southern Blue-ringed Octopus is the largest than other blue ringed octopus. They 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.
Species: H. maculosa
The size of Southern Blue-ringed Octopus is less than 2 mm in diameter. It weighs only 28 grams with a body to 5 cm long and arms to 10 cm. The dorsal surface of the mantle usually has a rough appearance covered by numerous irregularly arranged wrinkles. There are also fine, unevenly-sized tubercles covering the head and mantle. When it is resting, the background color is gray to beige, with large, light brown patches. On the dorsal mantle, 10 patches form a pattern of brown chevrons. Smaller patches dot the web and base of the arms. All eight arms are marked with approximately 10 evenly spaced brown patches that form bands running down the arms.
The blue rings are usually not visible in animals at rest. When the octopus is agitated, the brown patches darken dramatically, and iridescent blue rings or clumps of rings appear and pulsate within the maculae. Typically 50-60 blue rings cover the dorsal and lateral surfaces of the mantle. There has been some speculation that these color changes may have a communicative function, especially the pulsating blue of the excited state as for instance, a warning to potential predators and as a means of communicating amongst themselves.
Southern Blue-ringed Octopus feeds on small crabs, hermit crabs, and shrimp that it hunts during the day. There are two poison that are used against prey and predators. One poison is used for hunting crab. Other poison is used as self defense against predators. The poisons are secreted into the blue-ringed octopus's saliva, but the mechanism for poisoning its victim is not well understood. Either the poison is expelled in the saliva into the water or the octopus bites its prey or predator. Once the prey is dead, the octopus begins consuming it with its powerful beak-like mouth. Besideits beautiful appearance, the attractiveness of Southern Blue-ringed Octopus is its venom. The venom is extremely strong. It can cause nausea, vision loss and blindness, loss of senses, loss of motor skills, respiratory arrest.
Until now, there is no known its antidote for its venom. This poison is fatal and more potent than any poison found in land animals. Human victims can be saved if artificial respiration begins quickly. The only treatment is ongoing heart massage and artificial respiration until the poison dissipates (usually in 24 hours with no ill-effects). In fact, they are not aggressive and tend to avoid confrontation by flattening the body and blending into its surroundings. Humans have only been injured when a blue-ringed octopus is provoked or stepped on. When the threat is unavoidable, the blue-ringed octopus ejects a neuromuscular venom that contains maculotoxin and tetrodotoxin which cause paralysis.
Southern Blue-ringed Octopus is included in Octopodidae family. Octopodidae are considered the most intelligent invertebrates. They can essentially learn after very little trial and error. One example of their feats: They can uncork a bottle and remove a prey item if encountered. They also can learn by observing others. Experiments have shown that an Octopodidae who watches another do an unfamiliar task will be able to do it as well. They have an entire catalog of behaviors that are employed for concealment, defense, courtship, etc. They can change shape with remarkable facility from a flattened, formless blob to a threatening, upright shape that defies terrestrial description. Other behaviors are designed to disrupt the coherence of the body's outline include changing the shape of the mantle, twisting or waving arms, and erecting papillae that alter the animals texture and appearance.