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Animal Guide: Blue-Ringed Octopus

Blue-Ringed Octopus (Hapalochlaena maculosa)

  • Type: Cephalopod
  • Family: Octopodidae
  • Habitat: Shallow marine waters and tide pools
  • Location: Common off the coast of Australia and the western Pacific Ocean
  • Diet: Crabs, fish, and mollusks
  • Average lifespan in the wild: 2 years
  • Size: 5-7.8 in (12.7-20 cm)
  • Weight: .92 oz (26g)

With its fascinating coloring and delicate curling arms, the blue-ringed octopus may be a beautiful creature, but this small cephalopod is also deadly. The blue-ringed octopus appears grey or beige with light brown patches when it is at rest, but when agitated its 50 or 60 bright blue rings appear and pulsate with color, as a warning. Inside the salivary glands of the blue-ringed octopus live colonies of bacteria that produce tetrodotoxin, the potent neurotoxin found in pufferfish and other animals. A bite from a blue-ringed octopus can completely paralyze and kill an adult human in a matter of minutes. There is no known antidote. The octopus itself is not affected at all by the toxin-an evolutionary prerequisite for the symbiotic relationship that has developed between the blue-ringed octopus and the toxin-producing bacteria.

The blue-ringed octopus is commonly found in shallow, sandy areas surrounding the coastal reefs of Australia and the western Indio-Pacific. It is most active after dark, and spends most of its day hidden in its nest. Like all octopods, the blue-ringed octopus has no skeleton and is thus very flexible and maneuverable. It can squeeze into tiny crevices and make dens in bottles, aluminum cans, or mollusk shells. The blue-ringed octopus is also known to burrow into sand or gravel to conceal itself.

The blue-ringed octopus feeds primarily on crabs and mollusks, ambushing from behind and enveloping prey with its eight arms. Using its bird-like beak, the octopus bites a hole through its victim’s shell to inject toxic saliva. With its arms and beak, the creature tears soft pieces from the prey, sucking the rest of the meat from the shell once it becomes partially digested by the saliva.

Packets of sperm rest in the grooved tip of the male’s modified third arm, called a hectocotylus. When mating, the male slips this grooved tip under the mantle and into the oviduct of the female through a gill slit, and transfers multiple sperm packets, or spermatophores. The female lays her eggs in several unattached clumps, which she carries in her arms until they hatch. After the young emerge from their eggs, the mother dies.

Did you know: The blue-ringed octopus, like all octopuses, has three hearts and blue blood.

Related Episode: Encountering Sea Monsters

Photo © Gary Bell / Picture Quest

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50 responses
bob -- October 2nd, 2008 at 3:36 pm

it rocks!!

Johnny -- November 3rd, 2008 at 11:41 am

Totally Wicked

lashanda -- November 7th, 2008 at 12:01 pm

it sucked

tyler -- November 18th, 2008 at 10:43 am

that was the greatest article ever!!!

tucker -- November 20th, 2008 at 11:23 am

What the heck is a blueronged octopus

+

matt -- December 4th, 2008 at 9:16 pm

tucker, your an idiot…….the blue RINGED (not ronged) octopus is a type of octopus that is “commonly found in shallow, sandy areas surrounding the coastal reefs of Australia and the western Indio-Pacific” …which you would have know if u read the article before saying…..”what the heck is a blueronged octopus”………..how is it possible for anyone to be that ignorant

naners -- January 23rd, 2009 at 6:32 pm

i like matts comment da best! i luv matt!!!=P

bob -- January 28th, 2009 at 5:26 pm

yah um u guys are dumb its mabye 8 in

ashly -- January 30th, 2009 at 3:17 am

um nannars got some issues there yeah?

Tommy boy -- January 30th, 2009 at 1:02 pm

thts funny you ppl go from talking about the Blue Ringed Octopus to some kinda personal problems. I agree wit Matt on this as well. HAHAHA lol.

Tommy boy -- January 30th, 2009 at 1:10 pm

bob does size really matter?, its still cooly deadly!

Lane -- February 4th, 2009 at 6:18 pm

hello people

dj -- February 9th, 2009 at 12:58 pm

ya are spid

tub tub -- February 12th, 2009 at 12:36 pm

that is a cool

alexis -- February 25th, 2009 at 10:40 pm

Their SO cute! >.< imdoing an L.A project on them so this info is very useful! Ty.

Jayyne -- March 2nd, 2009 at 3:26 am

great information for marine studies assignment, thankksss. :)

babygurl -- March 3rd, 2009 at 10:18 pm

I sont think some of these paple even read the article, or really even care about, but Im doing a project on these things and they are SWEET! Did you know they have enough to kill 26 adult humans in minutes?! That is so cool!(but also kind of scary)

babygurl -- March 3rd, 2009 at 10:21 pm

its sad that the mommy dies after giving birth!

ChelseyAnn -- March 4th, 2009 at 9:39 pm

okay why in the world are you ppl having conversations on this article discussion board?

Anyways, the fact that this tiny little creature is so deadly is quite shocking, in my opinion. I would not want to step on one of those things :)

sophie;) -- March 12th, 2009 at 9:29 pm

hey i am doing i report and i hope i get an a++++ and if i dont then it will not be a happy day well bye gyes I LOVE ANIMALS!!!!

Wats it 2 ya -- March 16th, 2009 at 10:08 am

Im doing a report on this creature too! but I need to know what it’s predators are??? Please, someone respond IT’S DUE TOMOROW (TUES)!!!!

Sarah :-) -- March 16th, 2009 at 10:12 am

Sory im not sure. I really wish i could help! Someone please help her!!!

madasynnn -- March 16th, 2009 at 4:42 pm

Wow.I’m impressed. These things are really cool, actually. And I’m not a nerd or anything(no offense)but i sort of like this stuff. And i think a predator is what eats it like the predator of the shark is the killer whale. Yeah that’s it.

marcus dukes Md3 -- March 17th, 2009 at 10:33 am

This is like super cool. The facts about this cephalopod is very interesting.It can kill u witin 10 seconds. Did u kno dat?CHECK IT OUT. BYE!!!!!!!!

Sebastion -- March 21st, 2009 at 9:28 pm

the blue ronged octopus is pretty but deadly and i am doing a projet on it to so i hope i get an a++++!!!!

Anthony -- March 30th, 2009 at 11:13 am

Also doing a project on it, so I need to know the predator and the gestation period which I cant find on here. And Madasynn that person wants to know what the Blue ringed-Octopus’ predators are not the definition of it.

coen -- April 8th, 2009 at 9:59 pm

Whats the uses for it

Carl -- April 14th, 2009 at 7:22 pm

My mom says that they are the most poisonus thing in the world.

Victoria -- April 17th, 2009 at 5:20 pm

heyy Matt if you know so much about the Blue Ringed Octopus maby you could help me with a report i have on it. That would be very nice, cuz i can’t find anything on it almost at all. And + our school has blocked google, so i can’t use that! Thank You!!!!

Jane -- April 21st, 2009 at 7:25 pm

I’ve never know about the blue ring octopus untill now!

will -- April 27th, 2009 at 5:08 pm

it is so toatly wicked:I also never knew it could kill that many people with just its spit

dylan -- April 29th, 2009 at 10:58 am

its rocks

who wants to know -- May 4th, 2009 at 5:09 pm

cool cool ya i have a project du 2maro and really need info so this was grate tanks ;) <3madalyn

brittney -- May 6th, 2009 at 2:33 pm

i have project due next fri an thizzz helped alot thanx
luv ya!!!!!<3

vicster -- May 7th, 2009 at 12:38 pm

the predator of the blue-ring octopus is the moray eel

Amber -- May 12th, 2009 at 11:31 am

thanks! this helped alot :]

Alexa -- May 14th, 2009 at 8:13 pm

Really helped! This is an amazing species! Great to know more information :)

ashley -- May 15th, 2009 at 4:22 pm

matt you are so mean the blue ringed octopus is poinous so you think you know everything well think again loser

vicster -- May 16th, 2009 at 12:54 am

yeah what ashley said

tenchi -- May 17th, 2009 at 10:48 pm

Wow guys, most of these comments helped me out alot, as did the article. I also have a project due on the Blue Ringed Octopus, and I have been putting it of for a while so it helps when I can find fast sites like this. ;DD

billy -- May 19th, 2009 at 12:05 am

thnxs for information i needed it for an assighnment

Meenu -- May 31st, 2009 at 2:16 pm

this site was pretty useful for my marine project

phoebe -- June 23rd, 2009 at 4:18 am

this octopus is pitty cool i want see one live
and this site is really good for my report

patti -- June 30th, 2009 at 6:13 am

i love pbs..just when i thought i saw it all with the planet earth series pbs has equal intrest…great job

David -- September 1st, 2009 at 11:48 pm

i have a project on it too. i think its pretty funny how everyone is saying how they have a project on it tommorow. It probably cause they only decided to start researching what the octupus is the day before its due. lol

Amy -- September 11th, 2009 at 12:39 am

This is the best website I have found for the Blue Ringed Octopus! It will really help with my assighnment. Thankyou!

teijhan -- September 14th, 2009 at 3:13 pm

all of you are ignoring dont you know your wasting time

frank -- September 21st, 2009 at 6:04 pm

THIS IS AWESOME

emma -- September 22nd, 2009 at 8:23 pm

i hav a poject due 2morrow (wednsday) this helped so much thanx what else can you find out for me <;-D

mikey -- October 5th, 2009 at 2:54 pm

they reproduce oddly

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