Blue-rings: How dangerous are they?

Neogonodactylus

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I think we need a visit from "Myth Busters" here. Those of you who know me understand that I have worked for over 10 years trying to keep people from buying and displaying blue-rings in their home aquaria. There is danger, particularly to a child, should a bite occur. On the other hand, the fear of these animals is getting way over blown. In all probability if you were to be bitten (which is very unlikely), you would not be dead in three minutes. In fact, you might not die at all. Our lab has shown that the amount of TTX contained in blue-rings is highly variable from individual to individual and probably from species to species. Some individuals have barely detectable amounts of TTX. Others certainly have enough to kill you. The problem is there is know way to tell without assaying for the toxin. If bitten, unless you were alone or did not know that you were envenomated, you would survive with prompt medical care as a few Australians do each year. In the medical literature, there are only four confirmed deaths known to be caused by blue-ring bites. (That does not include the deaths from the "seafood stew" in Vietnam a couple of years ago.)

Should blue-rings be kept in the home aquarium? No, in my opinion the risk of an accidental envenomation to an unsuspecting person, particularly a child, is too great.

Should they be sold in aquarium stores? No, there is too great a chance that someone will get an animal that they do not know is dangerous.

Are blue-rings endangered? Probably not, at least not the named species including H. lunulata, H. fasciatus and H. maculaosa. Some of the undescribed species seem to be rarer and perhaps deserve protection. However, if we don't know what is out there, it is difficult to know how to deal with it.

Will you die if you put your hand in a tank with a blue-ring? Probably not unless you try to touch one. There is probably a greater chance of being electrocuted by an electrical short. But why take the risk. We all have ground fault interrupters on our aquaria, don't we?

Roy
 
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Should blue-rings be kept in the home aquarium? No, in my opinion the risk of an accidental envenomation to an unsuspecting person, particularly a child, is too great.

It should be allowed to ask: Ist this really so? In particular if I live alone and dont have any children? Then is my own responibility. But even I would be a famly-guy with kids:
Do Blue-rings really crawl out of their tanks to hunt people? We know this is nonsense.
The chance for children to be killed by a big dog is much, much greater, and no one claims for the prohibition of dobermans or pitbulls.
 

Neogonodactylus

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The dog mauling analogy is a bit off. There are 10s of millions of dogs that come in contact with children. I suspect that if there were that many blue-rings in home aquaria, we would have some deaths.

And yes, blue-rings do crawl out of tanks. Obviously they are not on the hunt to attack, but when you find one crawling across the floor, the urge is to quickly pick it up and get it back into the tank.

Roy
 

monty

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In light of this, what do you recommend we say and do with respect to people who want to keep blue rings? I usually try to paint a picture of the "worst case scenario," but it sounds like you think that that has gotten out of hand... I know from my neurobiology coursework that TTX is one of nature's more impressive neurotoxins, so I certainly would not want any animal that can inject it anywhere near my own skin. I guess I feel that as a source of information, we have some obligation to make sure people are aware of the risks, since these are often downplayed by the people selling octos to hobbyists.

I usually try to say something like "if you are bitten, you may have relatively little time between the onset of symptoms and incapacitation in which to call for medical help. If you don't get that help, you could die from respiratory paralysis." Do you think that's an inappropriately dire warning?
 

cthulhu77

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They should be kept the same as you would a venomous serpent. Locked room, no access to the public.

I do like Blue Rings, and I find them to be intelligent and placid animals, but would never keep them in a standard tank.

I also feel that they should not be sold in local fish stores, but of course, I feel that way about all wild caught octopus.
 

spinycheek

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I like the analogy to venomous snakes. I think people should be allowed to risk their own lives, but must use extreme caution when others are at risk. I also am a big fan of factual science, I can't even begin to explain how irritated I get when people say daddy-long-legs are the most venomous spiders, especially since they aren't even spiders and have no venom glands! Do captive bred blue-rings maintain their toxin? I wonder if they must be in the wild to accumulate the microbes that produce it.
 

DWhatley

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Am I totally misled on the daddy-long-legs? It has been my understanding that they do have a stomach toxin (but no way to externally transmit it).
 

spinycheek

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Yep, I don't know why that myth was ever started, but they have absolutely no venom. Some can secrete a noxious odor as a defense, but this is of no danger to anyone. They're distantly related to spiders and scorpions, but they can only bite with their chelicerae (non-venomous mouth parts), which can indeed puncture human skin, but they rarely actually bite. Most just scavenge on dead stuff.
 

Scrounger

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I was asking about octopus availability at one of the local fish stores around here, and the dude I was talking to mentioned the Blue Ring as one type that they could get through their supplier. I told him that I wouldn't be interested in one of those, and we began talking about the dangers involved with them. He told me a story about a "guy he knew" who put his arm into the tank after his Blue Ring Octopus had died, and the skin on his arm immediately developed a terrible rash, just becasue some of the venom had seeped into the aquarium.

I'm pretty sure he likes to get hiiiiigh.
 

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