TIL: The World's Longest Animal Is Over 50 Meters Long and It's A Worm!

in #steemstem3 years ago (edited)

If you hadn't read the title of the post and I asked you to guess what's the world's longest animal what would your answer be? Well, if you are like me you might have said blue whale or some kind of snake like anaconda. Blue whale is a good answer. After all, blue whales get to be almost 30 m long. As for anacondas, contrary to what the 1997 film would have you think, they are much, much smaller than that, with the biggest verified specimen being about 5.2 meters long.

So, you can imagine my suprise when I stumbled upon this press release today, mentioning that the world's longest animal is actually a worm and it gets to be a whooping 50 something meters long! The scientific name of the worm is  Lineus Longissimus and the press release is all about a new study on the species that found how it produces neurotoxins that can kill crabs and cockroaches. But more on the study later. Let's first get to know this worm a bit better. 

The species is commonly known as the bootlace worm and it belongs to the Nemertea phylum, a group of worms known as "ribbon worms" or "proboscis worms". The common name "proboscis worm" is due to an internal organ they have (called proboscis, duh!) that comes out of their mouth and helps them to eat and kill prey. Here's a video of another species, if you are curious how this proboscis thing looks in real life. Just jump to 00:55 for the good part! The content is a bit disturbing, you have been warned:

Although bootlace worms have the potential to grow extremely long, they have a width of only 5 to 10 mm. Their body is brown with lighter (longitudinal) stripes and like other ribbon worms they use their proboscis to immobilize prey. Most adults are 5-15 m long, with the record belonging to a specimen discovered back in 1864. That specimen was... 55 fucking meters long! 

Here's a photo to give you a better idea of how they look like:

Lineus longissimus, picture taken in Grevelingen near Scharendijke (the Netherlands)  (CC BY 3.0 ,credit)

And here's a really cool video, showing a Lineus longissimus specimen swallowing in hole a bunch of dead annelids:

Individuals are usually found at depths of 10m or deeper, on sandy and muddy shores and in tide pools. Their  distribution ranges from Iceland eastwards to the Atlantic, North Sea and Baltic Coasts of Europe and it is the most commonly recorded nemertean in Britain.

Like with most ribbon worms, there is really not much we know about these creatures and the published scientific literature is very limited. Now, let's see what the new study found out.

The New Study

As aforementioned, a new paper on these creatures came out a few days ago, appearing on the Scientific Reports journal. The name of the paper is "Peptide ion channel toxins from the bootlace worm, the longest animal on Earth." and no academic access is required to read it. The study was conducted by a research team from three Swedish universities and colleagues from Belgium and Australia, led by Ulf Göransson, Professor of Pharmacognosy, Department of Medicinal Chemistry in Uppsala University.

The too long didn't read version of the paper is that this is the first study to show that these worms produce, when threatened, a mucus containing a potent mix of neurotoxins. The researchers then isolated the most abundant toxin in the mixture and tried it on two model organisms, green crabs (Carcinus maenas) and Blaptica dubia cockroaches. In both cases, the toxin caused paralysis and death. 

Toxins often often work by affecting ion channels, which are pore-forming membrane proteins that allow ions to pass through the channel pore. In this case, the toxin messes with the sodium channels of crustaceans and insects. However, further testing showed that this reaction appears to be significantly less potent on mammals.

In their paper, the authors note that these findings are very encouraging and could be used to develop potent yet safe for humans insecticides:

Strong selectivity for insect over human sodium channels indicates that α-nemertides can be promising candidates for development of bioinsecticidal agents.
 These data are encouraging for the further exploration of α-1 as a bioinsecticide. [credit]

And that's pretty much the dumbed down version of the paper. It's a bit technical but if you have a  background in chemistry and/or life sciences you can check it out if you want to read all the technicalities.

Here's what  Prof. Göransson had to say about the study:

"This peptide toxin is the most poisonous substance to have been found in Sweden's animal kingdom and the fact that it may be possible to use it makes the discovery even more exciting. We already know that peptide toxins are found in, for example, cone shells that live in tropical waters. These ribbon worms live in colder waters, for example, the coastlines of Great Britain and Norway and the west coast of Sweden.
The peptide toxin has a very powerful effect on crustaceans and cockroaches, which is why it could serve as a very effective insecticide.  From a research point of view, it's exciting to have discovered a new toxin in our own fauna, in a group of animals that has basically never been explored. Moreover, the whole chain of research can be attributed to our team's effort, from discovering the substance in the bootlace worm to describing the structure of the toxin and studying its effect." [source

Reportedly, Prof. Göransson  even once tried to touch  a specimen bare-handed and didn’t feel much of anything. Still, he says he plans to use gloves routinely in future research. 

The End

So, today you learned that Lineus longissimus worms are the world's longest animals and they produce toxins that show very promising results for pesticide use in agriculture. Unfortunately, like with most "promising" research I doubt we will ever see any real life applications :)

Lately I am making a habit to close my posts with cool but totally unrelated animal videos and you seem to enjoy them, so here's another one, this time of a young mantis being preyed by a jumping spider.. Will it manage to escape? The ending might surprise you:

Oh yeah, here's another interesting fact I learned today. Apparently, a man in 2017 successfully received a penis transplantation after losing his own, 17 years prior to the surgery. There was a small problem though. He was black. And the donor was white! So, he had to receive medical skin darkening tattoos in order to correct the skin tone differences XD

Ok, I will stop now before getting more sidetracked!

See you tomorrow!

References & Further Reading

 - All references are provided in the form of clickable links in the main body of the post :) 



Great post @trumpman! It would be pretty amazing if we were ever able to develop a type of pesticide that would not be as harmful to us humans. In the developed world we don't often worry about the consequences due to good filtration masks, but there are so many people in developing countries who suffer from the damages caused by applying pesticides without a gas mask.

Prof. Göransson even once tried to touch a specimen bare-handed and didn’t feel much of anything

Haha, that's a pretty interesting way to test if something is harmful!

Yeah that would be nice but I guess its not happening anytime soon :(

And another problem would be that this unharmful pesticide would probably be more expensive, which again means that it's not something that would be used in the developing countries due to the cost. I guess I'm a bit pessimistic about this, despite the nice potential.

That mantis was one cool looking dude!


Those guys are creepy. Still pretty cool though.

Hello! Long worms are cool, but turn your attention to this little bastard. He is worthy of your attention Acanthaspis petax. Perhaps you already wrote about him?

Hehe, I have actually briefly mentioned this insect in a post but never dedicated a whole post to it? Why don't you give it a try? Rumors are thatbgood science posts with proper references get nice rewards! ;)

You are an expert, you have a huge experience, it's difficult to compete with you. I can not take your bread from you. It will be dishonest. )))

lol, just give it a try, it's not like I am the only guy posting about stuff like this XD Don't worry !

But this bug is even steeper. Apparently, he avenges frogs for mosquitoes and flies

Do you also know him? )))

FUCK! THATS FUCKING AMAZING! I am definitely making a post on this one if you don't 😂😂

I will not claim co-authorship )))

Aman me auta ta skoulikia re file ! xD

Σε επόμενο άρθρο θα βάλω και το δικό σου το σκουλήκακι ;)

Perimenw loipon ! Eukola trending kai 4 digit payout ! xD

Many people had believed that the blue whale is the longest animal. I guess they were very wrong.

About the penis transplant; why didn't he just get a bionic penis? :D

Is there such a thing? 😂

Lol. Of course there is. I once read a story of a man the was born without penis, but had a penis created for him. :)
I can dig up the link for you if want to view and have fun :p

"Promising"... In other words, we don't care to test because even we don't believe it's possible

Holy!! mother I thought it was the blue whale too hahaha good post!

We both got it wrong :D

Poor fella. A black guy having to live with a white guy's penis.

I could live with a black man's penis. As long as the stereotype is true!

It is scientifically proven that all stereotypes are 100% accurate.

I like worms! They're rich in protein!

Are you rich in protein ?

IDK, you're the one biting pieces of me off :P

Why is it so long??.. Looks irritating too.

Anacondas would have been my first thought

As for anacondas, contrary to what the 1997 film would have you think, they are much, much smaller than that, with the biggest verified specimen being about 5.2 meters long

I think you just destroyed one scary part of my childhood

My apologies :p

You're right, I never would have thought! Lineus LONGissimus... I bet they have the LONGest name as well... If you know what I'm sayin'. :P

Can't get myself to believe this, a worm 50m long? Damn, that is like more than 20 times the length of my bed. Well, it's alright, nature won't stop surprising us.

About the penis, I would have said something but let me hold my peace before some people would start saying I have a bad mind.

What would you have said? :D

Before this post I would argued, fought and even kill against the motion of a worm taking the price of being the longest living animal, damn it's quite long, nice one trumpman,you just added to the knowledge.

Yep! Thats a really unexpected winner!

his post is very good,
can add to my scientific treasures., I like the same post you

some say naked mole rats look like wrinkled dicks. do you agree? dick.jpg

It's worth checking your posts several times

I mean where my friend .., I do not understand and please guidance

Please guidance :O

wow very exactly .., definitely looking for prey

That 'proboscis' squirt scene at 55th second did not only bother me but also caused the places of my stomach and alimentary canals to change. 🤣You posted a really nice post. Thank you. I've been aware of the presence of a brand new creature in our ecosystem.

LOl, really. This is sick...I would bet a fortune had i not read this post about Lineus LONGissimus ( as @lordneroo noted)..The toxins emission is hell irritating!

Thanks for this funnyman. Trump indeed