There are at least 10 species of tiny blue-ringed octopuses, which, ironically for their size, are the most deadly of all cephalopods. Two well-known examples are the lesser Southern blue-ringed octopuses, Hapalochlaena maculosa Hoyle, , and the greater blue-ringed octopuses, Hapalochlaena lunulata , Quoy and Gaimard, The common name comes from the bright blue rings that appear when they are alarmed. Lesser Southern blue-ringed octopuses, Hapalochlaena maculosa , are the larger of the two and more common. They weigh only 28 grams with bodies to 5 cm long and arms to 10 cm. The dorsal upper surface of their mantle usually has a rough appearance covered by numerous irregularly arranged wrinkles.
|Published (Last):||7 December 2009|
|PDF File Size:||3.24 Mb|
|ePub File Size:||8.56 Mb|
|Price:||Free* [*Free Regsitration Required]|
Found most commonly in the tidal rock pools along the southern coast of Australia. Most commonly found in rocky, shallow pools of water or in shallow corals.
Also found under rocks in sandy or muddy stretches of bottom where alga is plentiful. Particularly common after storms when it can be found looking for crabs and bivalves. Moynihan , Campbell , Australian wildlife lectures , Rogerson , Park The blue-ringed octopus is a small octopus that ranges in size from 4 mm at birth to up to 20 cm in adulthood.
The most outstanding characteristic of this species is the iridescent blue rings in the eye spots. These rings are reported to "glow" when an individual is aggravated. The female will initiate reproduction by specific coloring and posturing. The male will then approach her to begin courtship. Courtship consists of "love play" Wood, and caressing. The male will then use the hectocotylus, a modified arm consisting of a groove between the suckers and ending in a spoonlike tip, to deposit the sperm in the female's oviduct, which is located under the mantle.
Shortly thereafter, the female will begin to lay her eggs and the brooding period will begin. Characteristic brooding of this species is for the female to carry the eggs in its arms. She will guard them for a period of fifty days, at which point they will hatch into planktonic "paralarva". Initially at birth, the octopus will be only 4 mm long. This stage of the life cycle, the young will float to the top and join the plankton for about a month.
At the end of this time period they will once again return to the bottom to resume their normal life. Microsoft Boyle Wood Hanlon and Messenger The blue ringed octopus is a nonaggressive octopus and in general exhibits the typical behaviors of octopuses: anachoresis, burrowing, and aposematism.
Anachoresis is living. Burrowing is where an octopus establishes a den or refuge for itself by excavation of sand, mud, gravel, and coral rubble. This can often pose a problem in an aquarium environment, where underground filters are common. Aposematism, or advertising toxicity, in this species includes the "glowing" Campbell of the iridescent blue rings, and often a yellow and black striping of the body. In general, not much is known of use of these displays in this particular species.
At one week of age, the blue ringed octopus will begin to eat crab pieces. As the octopus matures, it will begin to eat live crabs and bivalve mollusks. The octopus will either entice its prey into its vicinity and inject a poison into the water that will paralyze it or will inject the poison into its prey directly. It is also believed that the octopus will capture prey, forming an airtight pouch around it, and inserting the poison into the pouch, cause the prey to take the poison in through its respiratory system.
The poison is a neurotoxin which causes paralysis, which is particularly fatal if the poison affects either the heart or repiratory system. To date there is no antitoxin. Generally though, humans are not considered prey to this creature and a bite from one seems to be more of a defensive response than anything else. References: Boyle Loadsman and Thompson Park Berry This species lacks an ink sac and therefore has become a common addition to the marine aquarium.
This is much to the dismay of many toxicologists who feel that people selling and buying them are uninformed of the true danger they pose. This species also is used for its venom. One of Australia's major industries is its venom industry, in which the blue-ringed octopus plays a valuable role. This species is considered one of the most dangerous animals in the sea because of the toxicity of its venom.
In addition, the bite of the blue-ringed octopus is not painful. Therefore, there have been reported cases where people handled one and did not realize they had been bitten until the symptons of envenomation began to occur. There was no information on conservation efforts made for the blue-ringed octopus. A problem has begun to arise surrounding the publicity of the toxicity of its venom.
People have begun to over-react and kill octopuses encountered in shallow tidal pools. Though the blue ringed octopus carries a toxin which can kill humans, there has never yet been a report of an octopus attacking a human. In general this species is nonaggressive and will only bite if picked up or stepped on.
The name Blue-ringed Octopus is actually given to a large group consisting of about five different species. Two of these are Hapalochlaena lunulata and Hapalochlaena fasciata. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends.
Synapomorphy of the Bilateria. Anonymous, Microsoft Encarta 98 Encyclopedia , computer version ' Australian Wildlife Lectures, Berry, S. Boyle, P. Cephalopod Life Cycles v. Campbell, MD, E. Hanlon, R. Cephalopod Behaviour. Cambridge: Cambridge University Press. Loadsman, J. Moynihan, M.
Communication and Noncommunication by Cephalopods. Bloomington: Indiana University Press. Park, E. May, Around the Mall and beyond. Smithsonian , v. Rogerson, S. Travel: Just when you thought it safe Consumer Report.
The Daily Telegraph : pp. Sea World Inc. Wood, J. Help us improve the site by taking our survey. To cite this page: MacConnell, A. Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts.
While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control. Hapalochlaena maculosa Facebook. Geographic Range Indo-Pacific. Moynihan Sea World Inc Rogerson Biogeographic Regions australian native indian ocean native pacific ocean native Habitat Most commonly found in rocky, shallow pools of water or in shallow corals. Moynihan , Campbell , Australian wildlife lectures , Rogerson , Park Aquatic Biomes coastal Physical Description The blue-ringed octopus is a small octopus that ranges in size from 4 mm at birth to up to 20 cm in adulthood.
Campbell Rogerson Hanlon and Messenger Other Physical Features ectothermic bilateral symmetry Average mass 26 g 0. Hanlon and Messenger Behavior The blue ringed octopus is a nonaggressive octopus and in general exhibits the typical behaviors of octopuses: anachoresis, burrowing, and aposematism. Anachoresis is living in crevices and holes. Hanlon and Messenger , Campbell , Wood Food Habits At one week of age, the blue ringed octopus will begin to eat crab pieces.
Economic Importance for Humans: Positive This species lacks an ink sac and therefore has become a common addition to the marine aquarium. In addition this species has come under study to provide information on the mantle and the microscopic protrusions on the mantle of cephalopods.
Found most commonly in the tidal rock pools along the southern coast of Australia. Most commonly found in rocky, shallow pools of water or in shallow corals. Also found under rocks in sandy or muddy stretches of bottom where alga is plentiful. Particularly common after storms when it can be found looking for crabs and bivalves. Moynihan , Campbell , Australian wildlife lectures , Rogerson , Park The blue-ringed octopus is a small octopus that ranges in size from 4 mm at birth to up to 20 cm in adulthood. The most outstanding characteristic of this species is the iridescent blue rings in the eye spots.
Southern blue-ringed octopus
Blue-ringed octopuses , comprising the genus Hapalochlaena , are four highly venomous species of octopus that are found in tide pools and coral reefs in the Pacific and Indian oceans, from Japan to Australia. They eat small crustaceans , including crabs , hermit crabs , shrimp , and other small animals. They are recognized as one of the world's most venomous marine animals. The species tend to have a lifespan of approximately two years. This can vary depending on factors such as nutrition , temperature and the intensity of light in its habitat.
Southern Blue Ringed Octopus
Compiled distribution map provided by [data resource not known]. Browse the list of datasets and find organisations you can join if you are interested in participating in a survey for species like Hapalochlaena maculosa Hoyle, If you have images for this taxon that you would like to share with Atlas of Living Australia, please upload using the upload tools. Skip to content. Contact us Sign up My profile Login Logout. Online Resources. Compiled distribution map Compiled distribution map provided by [data resource not known].