What is the longest animal in the sea?

06 February 2017

Question

Ricky - What is the longest animal in the ocean?

Answer

Chris Smith put this question to Danni Green.

Danni - Well, although most people think it’s the blue whale and they can get to about 30 metres. The longest animal in the ocean, and indeed in the world, is actually the humble worm called the bootlace worm or Lineus longissimus, which it’s quite aptly named. It’s the longest recorded animal ever found and it washed up in about the mid 1800s after a big storm at St. Andrews, and it was about 55 metres long...

Chris S - This is just a worm?

Danni - … and about 10cms wide. And the thing about these ribbon worms is they a toxic proboscis that whips out and it has a neurotoxin in it that it uses to get its prey. So I don’t know what a 55 metre worm was preying on, but we don’t know what’s out there and how many more of these massive worms there are. It’s actually found
all round the UK as well these ribbon worms.

Chris B - I was wondering, does it have a nervous system that travels the whole lengths, so a nervous system that’s 55 metres long?

Danni - The smaller ones do yes, so I believe it would have. It’s amazing. Chris B - Wow! I wonder how long it takes for potentials to go from one end… Chris - Nerve impulses? Danni - That’s a good question.

Chris S - Because you’d think the sensory nerve information travels about one metre per second in small nerve fibres, doesn’t it? So it might take up to a minute to get your sensation. But motor information is 100 metres a second so movements might go a little bit faster. But that’s intriguing isn't it? Where do these worms hang out, they sound terrifying?

Danni - You find them all around the UK.

Chris S - Really?

Danni - Yeah. The bootlace worm - if you look it up there’s some really cool YouTube videos of them wriggling around. They awesome.

Chris S - What about land animals though Chris? You’re our Zoology/animal expert - biggest land animals?

Chris B - It would have to be a snake of some kind. So I wonder about the reticulated python

Danni - Was the question animal? Because if it was an organism it could be fungus. You know they those massive like - what are they called again?

Chris S - A mycorrhizal.

Danni - That’s a word a can never say, yeah. Those can be like hundreds and hundreds of metres, can’t they?

Chris S - They are literally hectares. I think they’re the biggest moving organism. It lives in America and it is a giant subserve fungal network which is hectares in size so that’s true. But in terms of land animals - how big is a giraffe in terms of its actual mass and that kind of thing? How much does one of those weight because they
don’t look like they would weigh much but they’re I guess actually quite big?

Chris B - Yeah. They vary from about 800 tons up to 1.2 tons sometimes. In terms of height, really, really tall giraffes are about 5 to 6 metres high. Chris S - Is this true Chris that they have special adaptations so they don’t explode their brain with their blood pressure becoming too high if they put their head down to drink? Is that true?

Chris B -Yeah, it’s a bit of problem. You’ve got to be able to push all this blood up to the head so you’ve got to work against gravity. But when giraffes lower their heads to drink, for example, they’ve got this problem of how do they actually stop their heads from exploding, their eyes popping out of their skulls? We think it’s because they’ve got a network of really find blood vessels that acts like a sponge. So it mops up this excess blood pressure when the head it is down and release it when the head is up.

Chris S - I was having a conversation, because medical people do this kind of thing, the other day about animals throwing up and we were speculating this might be a challenge for a giraffe. But then someone pointed out that they were ruminant animals, aren’t they, so they have a very good mechanism for regurgitating what’s in their stomach and chewing it back over again. So, in fact, they should be able to throw up without a problem.

Chris B - Yeah, it’s crazy. You can see food going down the neck and you can see it going back up as well. It’s really creepy when you watch it.

Chris S - Because someone said to me that you have to be careful with cows because if cows eat rhododendron this is very powerful as a mitogenic agent for them - it makes them throw up. And if you think the cow is the size of an oil drum, and a cow is an oil drum of liquid basically, just throwing up all in one go. And if a big field of cows eat rhododendron you can have a lot of cow vomit everywhere.

Chris B - If you see ruminants throwing up then you know something is seriously, seriously wrong. I’ve never seen a giraffe throw up and I hope I never do.

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