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Nasty Blue-ring


Haliphron Atlanticus
Staff member
Moderator (Staff)
Mar 17, 2003
There are currently four described species of blue-ringed octopus (Hapalochlaena). Norman in his book "Cephlapods: A World Guide" figures five additional undescribed species and I've seen a couple of others. While all blue-ringed species that have been examined appear to have TTX, species and even individuals vary considerably in the amount they contain. A blue-ring is not just a blue-ring. Some are definitely more dangerous than others.

One species confirmed to have been responsible for deaths is Norman's species #1 from Northern Australia. The largest of all Hapalochlaena with a mantle length of up to 6 cm, it definitely is toxic - and has the personality to match. While most H. lunulata that I deal with are quite shy and non-aggressive, this species seems much more bold and willing to stand its ground. While I don't recommend that anyone keep blue-rings in their home aquarium, this is definitely one to avoid. It is easy to spot because when excited it turns a deep maroon.



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Have you determined if the little guys lose some, if not all, of their toxicity when isolated in an aquarium? If my understanding is correct, the toxin is not produced directly by the animal but is symbiotic and it seems we would see far more deaths with careless keepers unless the toxin weakens or even disappears over time. I would never wish to keep one (part of my enjoyment of keeping octopuses is to interact with them) and would not encourage others but have always been curious about this possibility.
Very interesting D! I too would be interested in that.
Then if they were to be bred in captivity, the offspring would no longer be toxic? Thus making an excellent/safe addition to a nano, right? Becuase I seem to recall reading somewhere that the Blue Rings are much more active than any other Dwarf.
TO my knowledge, no one has looked at TTX titers in a second generation blue-ring although we have shown that paralarvae hatched in the lab contain TTX. We haven't even done the critical experiment to look at titers vs time in captivity. Nor are we sure that all of the TTX in blue-rings is derived from bacteria. It is possible that some might come from diet or that the blue-rings produce it themselves. There is a lot of work to do before I would put my hand into a tank of cultured blue-rings.

There is a lot of work to do before I would put my hand into a tank of cultured blue-rings.

LOL, the hand in the tank is why I would never keep one as I am way to much of a hand-on (in) person to keep anything that would hurt, let alone poison me. It did take one good (bad) hit from a lion fish in a bad location and a year for the finger to fully recover to teach me :oops: though and is why I wonder about the lack of incidences with blue rings in aquariums.

We first need to solve a way to fully culture any kind of small egg octopus before this can be studied but it is interesting that we don't even know if they produce it themselves. I was under the impression (I can't site the readings but have read it in several places, albeit so often once said and often quoted happens a lot) that this was already known not to be the case.
I wonder how many of these turn red like that. The one Ned DeLoach found (that you were unsure of being a bluering but Ned mentions seeing the rings that don't show in the picture) shows a similar coloration. Is the female chuncky like that too?
When I arrive by his side he was face-to-face with a strange little octopus perched on a white rock next to the rope. I have to stare, squint, blink and stare again before I finally see the faint outlines of blue rings scattered across the octopus’s mantle. I turn to show Johan, but he is off hunting again. I’ve been lucky enough to have seen several species of blue rings over the years and studied the photographs of hundreds more, but I have never seen another quite like this.


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That is what Ned said too (note they also found the elusive hairy octopus during this trip). Ned and Anna have done a lot of diving and exploring over Ned's years as an underwater photographer and have helped with a few new species so his observations are well schooled. Unfortunately, I don't believe they collected this oddity as they rarely collect animals themselves.

After looking at the picture a bit, I discovered you can actually make out some of the rings.


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