Mondo Knows Facts
An octopus has three hearts and blue blood
Two hearts pump through the gills and one serves the body Its blood uses haemocyanin, a copper based pigment that carries oxygen well in cold water but is less efficient than haemoglobin. Two thirds of its neurons sit in the arms, so each arm can work with limited reference to the head. The main heart stops beating while it swims, which is why octopuses prefer crawling. It sits in Mondo's animals collection, one of 200 facts that each trace back to the reference below.
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Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.
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More facts like this
An octopus has three heartsTwo pump blood to the gills and one pumps it around the body.The mimic octopus imitates other sea creaturesIt flattens, spreads or curls its arms to resemble a flounder, lionfish or sea snakeA blue ringed octopus flashes a warning before it bitesThe rings brighten when the animal is disturbedThe blue-ringed octopus carries venom strong enough to kill humansA tiny blue-ringed octopus holds enough tetrodotoxin to paralyse 26 adults.An elephant trunk has about 40,000 muscle unitsThat flexibility lets it lift a log or pick up a single seedA blue whale heart weighs about 180 kilogramsIts aorta is wide enough for a small child to crawl through
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Tags: octopus, blood, anatomy
An octopus has three hearts and blue blood: the short answers
- Where does this come from, and can I check it?
- Two hearts pump through the gills and one serves the body. The figure is taken from NOAA Ocean, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
- Is this really a animals fact?
- Yes. It sits on the Animals shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
- What else can I read about it?
- The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.