Blue-ringed octopus: Difference between revisions
→Venom: copy edits, rearranged to clarify |
Copy edit completed |
||
| Line 20: | Line 20: | ||
''[[Hapalochlaena nierstraszi|H. nierstraszi]]'' (?) |
''[[Hapalochlaena nierstraszi|H. nierstraszi]]'' (?) |
||
}} |
}} |
||
The '''blue-ringed octopuses''' ([[genus]] '''''Hapalochlaena''''') are three (or perhaps four) [[octopus]] [[species]] that live in [[tide pool]]s and [[coral reef]]s in the [[Pacific Ocean|Pacific]] and [[Indian Ocean]]s, from [[Japan]] to [[Australia]] |
The '''blue-ringed octopuses''' ([[genus]] '''''Hapalochlaena''''') are three (or perhaps four) [[octopus]] [[species]] that live in [[tide pool]]s and [[coral reef]]s in the [[Pacific Ocean|Pacific]] and [[Indian Ocean]]s, from [[Japan]] to [[Australia]]. Their primary habitate is around southern [[New South Wales]], [[South Australia]], and northern [[Western Australia]]).<ref>Surf Lifesaving Training Manual, 32nd edition</ref><ref>CBS News http://www.cbsnews.com/8301-202_162-57591718/tiny-but-deadly-spike-in-blue-ringed-octopus-sightings-sparks-fear-of-invasion-in-japan/</ref> They are recognized as one of the world's most poisonous marine animals.<ref>{{Cite web |url=http://animal.discovery.com/convergence/oceans-deadliest/deadliest-creatures/deadliest-creatures_05.html |title=Ocean's Deadliest: The Deadliest Creatures -- Greater Blue-Ringed Octopus |publisher=[[Animal Planet]]}}</ref> Despite their small size, {{convert|12|to|20|cm|in|abbr=on|0}}, and relatively docile nature, they are dangerous to [[human]]s if provoked and handled, because their venom is powerful enough to kill [[humans]]. |
||
They can be identified by their characteristic blue and black rings, and yellowish skin. When the octopus is agitated, the brown patches darken dramatically, 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. |
|||
They hunt small [[crab]]s, hermit crabs, and shrimp. |
|||
==Classification== |
==Classification== |
||
The genus was described by British zoologist [[Guy Coburn Robson]] in 1929.<ref>{{cite journal |last=Robson |first=G. C. |date=1929 |title=Notes on the Cephalopoda. - VIII. The genera and subgenera of Octopodinae and Bathypolypodinae |journal=Annals and Magazine of Natural History: Series 10 |volume=3 |issue=18 |pages=607-608 |doi=10.1080/00222932908673017}}</ref> There are |
The genus was described by British zoologist [[Guy Coburn Robson]] in 1929.<ref>{{cite journal |last=Robson |first=G. C. |date=1929 |title=Notes on the Cephalopoda. - VIII. The genera and subgenera of Octopodinae and Bathypolypodinae |journal=Annals and Magazine of Natural History: Series 10 |volume=3 |issue=18 |pages=607-608 |doi=10.1080/00222932908673017}}</ref> There are four confirmed species of ''Hapalochlaena'', and six possible species still being researched:<ref name=chime/> |
||
* [[Greater blue-ringed octopus]] (''Hapalochlaena lunulata'') |
* [[Greater blue-ringed octopus]] (''Hapalochlaena lunulata'') |
||
* [[Southern blue-ringed octopus]] or lesser blue-ringed octopus (''Hapalochlaena maculosa'') |
* [[Southern blue-ringed octopus]] or lesser blue-ringed octopus (''Hapalochlaena maculosa'') |
||
* [[Blue-lined octopus]] (''Hapalochlaena fasciata'') |
* [[Blue-lined octopus]] (''Hapalochlaena fasciata'') |
||
* '' |
* ''Hapalochlaena nierstraszi'' was described in 1938 from a single specimen from the [[Bay of Bengal]], with a second specimen caught and described in 2013.<ref name=chime>{{cite journal|last1=Rudramurthy|first1=N.|last2=Sethi|first2=S. N.|title=Blue ring Octopus, Hapalochlaena nierstraszi, from the Bay of Bengal along the Chennai Coast|journal=Fishing Chimes|date=November 2013|volume=33|issue=82-83|accessdate=24 June 2015}}</ref> |
||
==Behavior== |
==Behavior== |
||
An individual blue-ringed octopus tends to use its dermal [[chromatophore]] cells to camouflage itself until provoked, at which point it quickly changes color, becoming bright yellow with blue rings or lines. The blue-ringed octopus spends much of its life hiding in crevices. Like all |
An individual blue-ringed octopus tends to use its dermal [[chromatophore]] cells to camouflage itself until provoked, at which point it quickly changes color, becoming bright yellow with blue rings or lines. The blue-ringed octopus spends much of its life hiding in crevices. Like all octopuses, it can change its shape easily, which helps it to squeeze into crevices much smaller than itself. This helps safeguard the octopus from predators and it may even pile up rocks outside the entrance to its lair. In common with [[Octopoda]], the blue-ringed octopus swims by expelling water from its [[hyponome|funnel]] in a form of [[jet propulsion]]. |
||
===Feeding=== |
===Feeding=== |
||
The blue-ringed octopus diet typically consists of small [[crab]]s and [[shrimp]], but they may also feed on 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 [[cephalopod beak|horny beak]] to pierce through the tough [[exoskeleton]], releasing its venom. The venom paralyzes the muscles required for |
The blue-ringed octopus diet typically consists of small [[crab]]s, and [[shrimp]], but they may also feed on 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 [[cephalopod beak|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== |
==Reproduction== |
||
| Line 40: | Line 44: | ||
Blue-ringed octopus females lay only one clutch of about 50 eggs in their lifetimes towards the end of autumn. Eggs are laid then incubated underneath the female's arms for about six months, and during this process she does 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. |
Blue-ringed octopus females lay only one clutch of about 50 eggs in their lifetimes towards the end of autumn. Eggs are laid then incubated underneath the female's arms for about six months, and during this process she does 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. |
||
== |
== Poisoning == |
||
| ⚫ | 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 [[Envenomation|envenomated]] until [[respiratory depression]] and [[paralysis]] start to set in.<ref>{{cite web | url = http://www.barrierreefaustralia.com/the-great-barrier-reef/blueringedoctopus.htm | title = Dangers on the Barrier Reef | accessdate = 2006-12-06 |archiveurl = http://web.archive.org/web/20061205092145/http://www.barrierreefaustralia.com/the-great-barrier-reef/blueringedoctopus.htm <!-- Bot retrieved archive --> |archivedate = 2006-12-05}}</ref> No blue-ringed octopus [[antivenom]] is available yet, making it one of the deadliest reef inhabitants in the ocean. |
||
=== Venom === |
|||
[[Image:Blue-ringed-octopus.jpg|thumb|Blue-ringed octopus from [[New South Wales]], [[Australia]]]] |
[[Image:Blue-ringed-octopus.jpg|thumb|Blue-ringed octopus from [[New South Wales]], [[Australia]]]] |
||
The blue-ringed octopus is {{convert|12|to|20|cm|in|abbr=on|0}}, but its venom is powerful enough to kill [[humans]]. No blue-ringed octopus [[antivenom]] is available yet, making it one of the deadliest reef inhabitants in the ocean. |
|||
The octopus produces venom containing [[tetrodotoxin]], [[histamine]], [[tryptamine]], [[octopamine]], [[taurine]], [[acetylcholine]], and [[dopamine]]. 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, if it occurs, is usually from suffocation due paralysis of the diaphram. |
The octopus produces venom containing [[tetrodotoxin]], [[histamine]], [[tryptamine]], [[octopamine]], [[taurine]], [[acetylcholine]], and [[dopamine]]. 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, if it occurs, is usually from suffocation due paralysis of the diaphram. |
||
| Line 50: | Line 56: | ||
A person has to be in contact with the octopus to be poisoned. The octopus's first instinct is to flee. If the threat persists, the octopus will go into a defensive stance, and show its blue rings. Only if cornered, and touched, will a person be in danger of being poisoned. |
A person has to be in contact with the octopus to be poisoned. The octopus's first instinct is to flee. If the threat persists, the octopus will go into a defensive stance, and show its blue rings. Only if cornered, and touched, will a person be in danger of being poisoned. |
||
== |
=== Effects === |
||
Tetrodotoxin causes severe and often total body paralysis. Tetrodotoxin envenomation can result in victims being fully aware of their surroundings but unable to breathe. 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, however, 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. |
|||
=== Treatment === |
|||
[[First aid]] treatment is pressure on the wound and [[artificial respiration]] once the paralysis has disabled the victim's respiratory muscles, which often occurs within minutes of being bitten. Because the venom primarily kills through paralysis, victims are frequently saved if [[artificial respiration]] is started and maintained before marked [[cyanosis]] and [[hypotension]] develop. Efforts should be continued even if the victim appears not to be responding. Respiratory support, together with reassurance, until medical assistance arrives ensures the victims will generally recover well. |
|||
It is essential that rescue breathing be continued without pause until the paralysis subsides and the victim regains the ability to breathe on their own. This is a daunting physical prospect for a single individual, but use of a [[bag valve mask]] respirator reduces fatigue to sustainable levels until help can arrive. |
|||
Definitive [[hospital]] treatment involves placing the patient on a [[medical ventilator]] until the toxin is removed 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. Victims who survive the first 24 hours usually recover completely.<ref>Lippmann, John and Bugg, Stan, "DAN S.E. Asia-Pacific Diving First Aid Manual", J.L. Publications, Australia, May 2004. ISBN 0-646-23183-9</ref> |
|||
Definitive [[hospital]] treatment involves placing the patient on a [[medical ventilator]] until the toxin is removed by the body. |
|||
Efforts should be continued even if the victim appears not to be responding. Tetrodotoxin envenomation can result in victims being fully aware of their surroundings but unable to breathe. Because of the paralysis that occurs, they have no way of signaling for help or any way of indicating distress. Respiratory support, together with reassurance, until medical assistance arrives ensures the victims will generally recover well. |
|||
Victims who survive the first 24 hours usually recover completely.<ref>Lippmann, John and Bugg, Stan, "DAN S.E. Asia-Pacific Diving First Aid Manual", J.L. Publications, Australia, May 2004. ISBN 0-646-23183-9</ref> |
|||
| ⚫ | 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 [[Envenomation|envenomated]] until [[respiratory depression]] and [[paralysis]] start to set in.<ref>{{cite web | url = http://www.barrierreefaustralia.com/the-great-barrier-reef/blueringedoctopus.htm | title = Dangers on the Barrier Reef | accessdate = 2006-12-06 |archiveurl = http://web.archive.org/web/20061205092145/http://www.barrierreefaustralia.com/the-great-barrier-reef/blueringedoctopus.htm <!-- Bot retrieved archive --> |archivedate = 2006-12-05}}</ref> |
||
==References==<!-- Pacific Science (2002), vol. 56, no. 3:255–257 --> |
==References==<!-- Pacific Science (2002), vol. 56, no. 3:255–257 --> |
||
Revision as of 21:04, 24 June 2015
| Blue-ringed octopus | |
|---|---|
| |
| Greater blue-ringed octopus (Hapalochlaena lunulata) | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Order: | |
| Family: | |
| Subfamily: | |
| Genus: | Hapalochlaena Robson, 1929
|
| Species | |
The blue-ringed octopuses (genus Hapalochlaena) are three (or perhaps four) octopus species that live in tide pools and coral reefs in the Pacific and Indian Oceans, from Japan to Australia. Their primary habitate is around southern New South Wales, South Australia, and northern Western Australia).[1][2] They are recognized as one of the world's most poisonous marine animals.[3] Despite their small size, 12 to 20 cm (5 to 8 in), and relatively docile nature, they are dangerous to humans if provoked and handled, because their venom is powerful enough to kill humans.
They can be identified by their characteristic blue and black rings, and yellowish skin. When the octopus is agitated, the brown patches darken dramatically, 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.
They hunt small crabs, hermit crabs, and shrimp.
Classification
The genus was described by British zoologist Guy Coburn Robson in 1929.[4] There are four confirmed species of Hapalochlaena, and six possible species still being researched:[5]
- Greater blue-ringed octopus (Hapalochlaena lunulata)
- Southern blue-ringed octopus or lesser blue-ringed octopus (Hapalochlaena maculosa)
- Blue-lined octopus (Hapalochlaena fasciata)
- Hapalochlaena nierstraszi was described in 1938 from a single specimen from the Bay of Bengal, with a second specimen caught and described in 2013.[5]
Behavior
An individual blue-ringed octopus tends to use its dermal chromatophore cells to camouflage itself until provoked, at which point it quickly changes color, becoming bright yellow with blue rings or lines. The blue-ringed octopus spends much of its life hiding in crevices. Like all octopuses, it can change its shape easily, which helps it to squeeze into crevices much smaller than itself. This helps safeguard the octopus from predators and it may even pile up rocks outside the entrance to its lair. In common with Octopoda, the blue-ringed octopus swims by expelling water from its funnel in a form of jet propulsion.
Feeding
The blue-ringed octopus diet typically consists of small crabs, and shrimp, but they may also feed on 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
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. A male mates with a female by grabbing her, which sometimes completely obscures the female's vision, then transferring sperm packets by inserting his hectocotylus into her mantle cavity repeatedly. 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.[6]
Blue-ringed octopus females lay only one clutch of about 50 eggs in their lifetimes towards the end of autumn. Eggs are laid then incubated underneath the female's arms for about six months, and during this process she does 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.
Poisoning
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.[7] No blue-ringed octopus antivenom is available yet, making it one of the deadliest reef inhabitants in the ocean.
Venom
The octopus produces venom containing tetrodotoxin, histamine, tryptamine, octopamine, taurine, acetylcholine, and dopamine. 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, if it occurs, is usually from suffocation due paralysis of the diaphram.
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,[8] a neurotoxin also found in pufferfish, and in some poison dart frogs.[9] Tetrodotoxin is 1,200 times more toxic than cyanide.[10] Tetrodotoxin blocks sodium channels, causing motor paralysis, and respiratory arrest within minutes of exposure. The tetrodotoxin is produced by bacteria in the salivary glands of the octopus.[11]
A person has to be in contact with the octopus to be poisoned. The octopus's first instinct is to flee. If the threat persists, the octopus will go into a defensive stance, and show its blue rings. Only if cornered, and touched, will a person be in danger of being poisoned.
Effects
Tetrodotoxin causes severe and often total body paralysis. Tetrodotoxin envenomation can result in victims being fully aware of their surroundings but unable to breathe. 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, however, 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.
Treatment
First aid treatment is pressure on the wound and artificial respiration once the paralysis has disabled the victim's respiratory muscles, which often occurs within minutes of being bitten. Because the venom primarily kills through paralysis, victims are frequently saved if artificial respiration is started and maintained before marked cyanosis and hypotension develop. Efforts should be continued even if the victim appears not to be responding. Respiratory support, together with reassurance, until medical assistance arrives ensures the victims will generally recover well.
It is essential that rescue breathing be continued without pause until the paralysis subsides and the victim regains the ability to breathe on their own. This is a daunting physical prospect for a single individual, but use of a bag valve mask respirator reduces fatigue to sustainable levels until help can arrive.
Definitive hospital treatment involves placing the patient on a medical ventilator until the toxin is removed by the body.
Victims who survive the first 24 hours usually recover completely.[12]
References
- ^ Surf Lifesaving Training Manual, 32nd edition
- ^ CBS News http://www.cbsnews.com/8301-202_162-57591718/tiny-but-deadly-spike-in-blue-ringed-octopus-sightings-sparks-fear-of-invasion-in-japan/
- ^ "Ocean's Deadliest: The Deadliest Creatures -- Greater Blue-Ringed Octopus". Animal Planet.
- ^ Robson, G. C. (1929). "Notes on the Cephalopoda. - VIII. The genera and subgenera of Octopodinae and Bathypolypodinae". Annals and Magazine of Natural History: Series 10. 3 (18): 607–608. doi:10.1080/00222932908673017.
- ^ a b Rudramurthy, N.; Sethi, S. N. (November 2013). "Blue ring Octopus, Hapalochlaena nierstraszi, from the Bay of Bengal along the Chennai Coast". Fishing Chimes. 33 (82–83).
{{cite journal}}:|access-date=requires|url=(help) - ^ Cheng, M.W. & R.L. Caldwell 2000. Sex identification and mating in the blue-ringed octopus, Hapalochlaena lunulata. Anim Behav. 60(1): 27-33.
- ^ "Dangers on the Barrier Reef". Archived from the original on 2006-12-05. Retrieved 2006-12-06.
- ^ Sheumack DD, Howden ME, Spence I, Quinn RJ (1978). "Maculotoxin: a neurotoxin from the venom glands of the octopus Hapalochlaena maculosa identified as tetrodotoxin". Science. 199 (4325): 188–9. doi:10.1126/science.619451. PMID 619451.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Daly, J.W., Gusovsky, F., Myers, C.W., Yotsuyamashita, M., and Yasumoto, T. (1994). "1st Occurrence of Tetrodotoxin in a Dendrobatid Frog (Colostethus-Inguinalis), with Further Reports for the Bufonid Genus Atelopus". Toxicon. 32 (3): 279–285. doi:10.1016/0041-0101(94)90081-7. PMID 8016850.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Furlow, Bryant. "Tetrodotoxin and the Life Tree". Retrieved 2011-04-22.
- ^ Dr. Roy Caldwell. "What makes blue-rings so deadly?". Retrieved 2007-03-19.
- ^ Lippmann, John and Bugg, Stan, "DAN S.E. Asia-Pacific Diving First Aid Manual", J.L. Publications, Australia, May 2004. ISBN 0-646-23183-9
