HAPALOCHLAENA MACULOSA PDF

Blue-lined octopus Hapalochlaena fasciata Hapalochlaena nierstraszi was documented and described in from a single specimen found in the Bay of Bengal , with a second specimen caught and described in Like all octopuses, they can change shape easily, which helps them to squeeze into crevices much smaller than themselves. This, along with piling up rocks outside the entrance to its lair, helps safeguard the octopus from predators. Variable ring patterns on mantles of Hapalochlaena lunulata If they are provoked, they quickly change color, becoming bright yellow with each of the rings flashing bright iridescent blue within a third of a second as an aposematic warning display. In the greater blue-ringed octopus Hapalochlaena lunulata , the rings contain multi-layer light reflectors called iridophores. These are arranged to reflect blue—green light in a wide viewing direction.

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Blue-lined octopus Hapalochlaena fasciata Hapalochlaena nierstraszi was documented and described in from a single specimen found in the Bay of Bengal , with a second specimen caught and described in Like all octopuses, they can change shape easily, which helps them to squeeze into crevices much smaller than themselves.

This, along with piling up rocks outside the entrance to its lair, helps safeguard the octopus from predators. Variable ring patterns on mantles of Hapalochlaena lunulata If they are provoked, they quickly change color, becoming bright yellow with each of the rings flashing bright iridescent blue within a third of a second as an aposematic warning display.

In the greater blue-ringed octopus Hapalochlaena lunulata , the rings contain multi-layer light reflectors called iridophores. These are arranged to reflect blue—green light in a wide viewing direction. Beneath and around each ring there are dark pigmented chromatophores which can be expanded within 1 second to enhance the contrast of the rings.

There are no chromatophores above the ring, which is unusual for cephalopods as they typically use chromatophores to cover or spectrally modify iridescence. The fast flashes of the blue rings are achieved by using muscles which are under neural control.

Under normal circumstances, each ring is hidden by contraction of muscles above the iridophores. When these relax and muscles outside the ring contract, the iridescence is exposed thereby revealing the blue color. Feeding[ edit ] The blue-ringed octopus diet typically consists of small crabs and shrimp. They also tend to take advantage of small injured fish if they can catch them. The blue-ringed octopus pounces on its prey, seizing it with its arms and pulling it towards its mouth.

It uses its horny beak to pierce through the tough crab or shrimp exoskeleton , releasing its venom. The venom paralyzes the muscles required for movement, which effectively kills the prey. Reproduction[ edit ] The mating ritual for the blue-ringed octopus begins when a male approaches a female and begins to caress her with his modified arm, the hectocotylus.

Mating continues until the female has had enough, and in at least one species the female has to remove the over-enthusiastic male by force. Males will attempt copulation with members of their own species regardless of sex or size, but interactions between males are most often shorter in duration and end with the mounting octopus withdrawing the hectocotylus without packet insertion or struggle.

After the eggs hatch, the female dies, and the new offspring will reach maturity and be able to mate by the next year. Toxicity[ edit ] The blue-ringed octopus, despite its small size, carries enough venom to kill 26 adult humans within minutes.

Their bites are tiny and often painless, with many victims not realizing they have been envenomated until respiratory depression and paralysis start to set in. The venom can result in nausea , respiratory arrest , heart failure , severe and sometimes total paralysis , blindness , and can lead to death within minutes if not treated.

Death is usually from suffocation due to paralysis of the diaphragm. The major neurotoxin component of the blue-ringed octopus is a compound that was originally known as maculotoxin but was later found to be identical to tetrodotoxin , [10] a neurotoxin also found in pufferfish , and in some poison dart frogs. The tetrodotoxin is produced by bacteria in the salivary glands of the octopus. If the threat persists, the octopus will go into a defensive stance, and show its blue rings.

If the octopus is cornered, and touched, the person would be in danger of being bitten and envenomated. In fact, the mother will even inject the neurotoxin into her eggs to make them generate their own venom before hatching. Tetrodotoxin envenomation can result in victims being fully aware of their surroundings but unable to move.

Because of the paralysis that occurs, they have no way of signaling for help or any way of indicating distress. The victim remains conscious and alert in a manner similar to curare or pancuronium bromide.

This effect is temporary and will fade over a period of hours as the tetrodotoxin is metabolized and excreted by the body. The symptoms vary in severity, with children being the most at risk because of their small body size. Because the venom primarily kills through paralysis, victims are frequently saved if artificial respiration is started and maintained before marked cyanosis and hypotension develop.

World Register of Marine Species. Flanders Marine Institute. Retrieved 3 February Animal Planet. Archived from the original on The genera and subgenera of Octopodinae and Bathypolypodinae".

Annals and Magazine of Natural History. Series Rudramurthy, N. November Fishing Chimes. The Journal of Experimental Biology.

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Blue-ringed octopus

Description[ edit ] The blue-ringed species are known for their small size, yet the southern variety is hailed as the largest of the genus. As a result, they have been classified as their own species. From arm to arm, most of these octopuses are no larger than 20 centimeters. This is larger by roughly 5 centimeters on average with other varieties of the blue-ringed octopus. When at peace, their coloring is often a drab, mucus like color. However, once it feels sufficiently threatened, the eponymous blue-rings suddenly appear. These octopuses have an average of about 60 rings that have multilayer reflectors that allow them to flash a blue green color.

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