Blue-ringed Octopus – World’s Most Venomous Marine Animals
Blue-ringed Octopus Species
There are at least ten species of the tiny blue-ringed octopus, which ironically for their size, are the deadliest of all cephalopods, but only four have been formally named. All these are inhabitants of Asian pacific waters. The common name comes from bright blue rings that appear when they are alarmed or attacked. These four species are as below.
Greater blue-ringed octopus (Hapalochlaena lunulata) is restricted to the tropical western Pacific Ocean including Papua New Guinea, Solomon Islands, the Philippines, and Indonesia.
Southern blue-ringed octopus or lesser blue-ringed octopus (Hapalochlaena maculosa) is Maximum size of 20 cm across arms, a body length of 12 cm, found along the coastline of south Western Australia to eastern Victoria, including Tasmania.
Blue-lined octopus (Hapalochlaena fasciata) appear as lines, instead of rings on the body; occurs chiefly along the coastline of eastern Australia to Victoria.
The rare occurrence of the Blue-ring Octopus apprises us of the importance of this Octopus in relation to its venomous nature and importance from the medical angle. Because medical and psychological researchers are interested in the tetrodotoxin neurotoxin found in its venom for its aphrodisiac effect and its ability to block voltage-sodium channels.
Morphometric Characteristics and Habitats
The blue-ringed octopus is one of the jewels of the ocean. It has vivid blue rings visible over the body when hunting, courting, or alarmed. They are normally grown at a length of 12 to 20 cm. They are considered one of the world’s most venomous marine animals.
When this octopus is agitated, the brown patches darken dramatically, and iridescent blue rings or clumps of rings appear and pulsate within the maculae. Typically, around 50 to 60 blue rings cover the dorsal and lateral surface of the mantle. They are frequently shallow rocky reefs in the intertidal and subtidal zones, avoiding surf conditions.
They eat small crabs, hermit crabs, and shrimp exoskeleton and may bite attackers including humans if provoked. They also take advantage of small injured fish and seizing them with their arms and pulling them into their mouth. The octopus uses its beak to release its venom paralyzes the muscles essential for movement, which effectively kills the prey.
Blue-ringed octopus females lay only one clutch of 50 to 100 eggs in their whole life. The eggs are laid and then they are incubated underneath the female arms for approximately six months. Thus, during this process, she will not eat and dies after the egg hatch. Although it the small in size and relatively docile in nature, its venom is powerful enough to kill anyone even human is not safe from him.
Most species of blue-ringed octopuses live less than two years, reaching sexual maturity at four months. The newly hatched juveniles feed on the yolk sac until about four weeks of age when juveniles begin attacking live crabs. Observational studies indicate that venom is active even at an early age.
The blue-ringed octopus spends much of its life cycle hiding camouflage patterns in cervices amongst the rocks, inside seashells, discarded bottles, and stones in the shallow water. Moreover, like all octopuses, it can change its shape with no trouble. This helps it to squeeze into crevices much smaller than itself.
This is also helping in safeguarding the octopus from predators. In common with other octopus swims by expelling water from their funnel in a form of jet propulsion. If the blue-ringed Octopus loses an arm, he can regenerate it within 6 weeks. Hence, it has regeneration power.
The powerful venom is a neurotoxin called tetrodotoxin. The Octopus has also found him in pufferfish and is ten thousand more toxic than cyanide. It infected the toxin using its beak, causing motor paralysis and respiratory arrest within a minute and leading to cardiac arrest due to lack of oxygen.
The Blue ringed octopus carries enough venom to kill 26 adult humans within a minute. Their bites though are tiny and often painless, with many victims not realizing that they have been envenomated until respiratory depression and paralyzing start to set in.
Clinical Symptoms of Blue-ringed Octopus Bite
The symptoms of a bite are respiratory arrest which can occur within a minute as the toxin blocks nerve transmission. Other symptoms include vomiting, muscle weakness, and paralysis of respiratory muscles. Victims are fully awake until a lack of oxygen, from the inability to breathe leads to unconsciousness.
Positive Values of Blue-ring Octopus venom:
Although another Octopodidae is used from biomedical research, behavioral research and as a gourmet food source, Hapalochlaena sp. Are too small and too dangerous for many of these uses.
Medical and psychological researchers are interested in the tetrodotoxin neurotoxin found in its venom for its aphrodisiac effect and its ability to block voltage-sodium channels.
So, an action potential in neurons is inhibited or reduced. They also have value as an unusual luxury item. As strange as it may seem an individual H. lunulate was sold at an expensive value.
Negative Values of Blue-ring Octopus venom
Poison from Hepalochlacna sp. Has proven to be fatal to humans particularly for young children. There is no anti-venom for this poison. Of the several human fatalities attributed to this potent species. All have involved the animal being picked up. The bite itself may not even be felt. Five minutes or so later, however, the victim may complain of dizziness and increasing difficulty in breathing.
The powerful venom acts on the victim’s voluntary muscles, paralyzing the muscles, required for body movement and breathing. Artificial respiration is necessary to maintain life. The poison gradually wears off after 24 hours apparently leaving no side effects. Moreover, compression immobilization bandaging is used for envenomation’s where a large amount of venom is placed in one area. If any human survives the first 24 hours normally recover from potent venom.
To function as an aposematic warning display, the display colors must be within the limits of the visual system of the relevant predator species. Thus, the peak reflectance of the blue ring lies within the range of mid and long wavelength. It is penetrating opsins of likely marine vertebrate and invertebrate predators, together with cetaceans, birds, pinnipeds, teleost fishes, and cephalopods.
Besides, the blue-green part of the visible spectrum is the most protuberant ambient underwater light field. Hence the iridescence is spectrally well-tuned to be maximally visible. Also, the peak reflectance of the iridescence also resembles the spectral absorbance of some of the recognized cephalopod visual pigments.