How Leeches Are Helping to Save Endangered Species
HTML-код
- Опубликовано: 22 сен 2024
- Visit brilliant.org/... to get started learning STEM for free. The first 200 people will get 20% off their annual premium subscription and a 30-day free trial.
Leeches are bloodsucking parasites, and you wouldn't think they're great at protecting other species. Yet for some conservationists, these little vampires are one of the best tools available for conserving endangered and threatened species.
Hosted by: Hank Green (he/him)
----------
Support us for $8/month on Patreon and keep SciShow going!
/ scishow
Or support us directly: complexly.com/...
Join our SciShow email list to get the latest news and highlights:
mailchi.mp/sci...
----------
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever: Odditeas , Garrett Galloway, Friso, DrakoEsper , Kenny Wilson, Lyndsay Brown, Jeremy Mattern, Jaap Westera, Rizwan Kassim, Harrison Mills, Jeffrey Mckishen, Matt Curls, Eric Jensen, Chris Mackey, Adam Brainard, Ash, You too can be a nice person, Piya Shedden, charles george, Alex Hackman, Kevin Knupp, Chris Peters, Kevin Bealer, Jason A Saslow
----------
Looking for SciShow elsewhere on the internet?
SciShow Tangents Podcast: scishow-tangen...
TikTok: / scishow
Twitter: / scishow
Instagram: / thescishow
Facebook: / scishow
#SciShow #science #education #learning #complexly
----------
Sources: docs.google.co...
Visit brilliant.org/scishow/ to get started learning STEM for free. The first 200 people will get 20% off their annual premium subscription and a 30-day free trial.
Finally!
We will be able to find the famed Big Foot & put to rest that it does exist! Haha LoL
Back in the 70s (I'm old, be kind) I wrote a term paper for a Biology Class called "Our Friend, The Leech" which then turned into an even more unhinged Toastmaster speech. Thank you for backing up my assertions from decades ago. Our friend, indeed, is The Leech!
Now I want to hear your speech!
HA! old 🫵😂
Sorry I couldn't help myself
No one cares
@@MaekarManastormno one cares about you maybe, but obviously people cared enough to like this persons comment.
😂😉Did you have an accompanying film strip?
Got my start in Toastmasters, too.👍
- If you have blood, they will happily find you.
I see that we are starting the day with joyful existential dread.
Tbf, at least they aren't mosquitos.
Sounds like the advertisement of a new Dracula horror movie tbh
Position: Research assistant
Location: Outdoors
Experience Needed: None
Key Attributes: Must be hemogenic
Must have blood n stuff.
"tummies full of data"... this is why I love the writers for Sci Show
Possibly the first time the phrase "bitey little blood libraries" has ever been used.
I love how quickly eDNA has gone from hare-brained idea to practical utility.
yes! it still blows my mind that this can be done.
what specific applications of eDNA do you think the best?
TIL how to spell harebrained. Why did I think it was hair for almost 30 years of my life. 😂
"Bity little blood libraries"!
when my son was young [about 9 I think] he caught a leech in a jar in the local paddling ford.
He sat for ages, trying to get it to attach, but it was a fish leech, so he was disappointed.
I found a leach in my quarantine tank for a pair of new Oscar fish and it is definitely showing why it’s important to quarantine animals before adding them to something that in this case is a 325 gallon pond that has sail fin plecos in it and they could definitely get harmed by them
When I was a child and didn't know what leeches were I was swimming in a lake and I got one on my leg. I was really excited to have a friend and I was so upset when my parents said we had to remove it.
I hate it when leeches lobby for my sympathy. It's extortion
These leeches left scientists speechless.
The study of how far can a leach travel after eating is absolutely an IgNobel waiting to happen
With some brave scientists experimenting on themselves, of course 💪🤓
...TERRESTRIAL leeches! Thanks for unlocking a new fear, and another reason my next vacation will be somewhere cold. 😂
So true! ANOTHER reason why I continue to live where the air hurts my lungs for months at a time.
Great use of leeches other than reattaching fingers and whatnot.
Grats on 8mil Subscribers!
Uh, I didn’t know there are terrestrial leeches. That is mildly terrifying
I had zero clue leeches live on land
I knew there were land leeches in madagascar, but no clue they were on any mainland, let alone several.
I learned that pretty recently myself. Turns out they live anywhere things with blood live. I don't think any fly, but plenty live in trees and drop on animals passing underneath.
@@laser8389 I’d freak out if one fell from the sky and landed on me
@@laser8389 i used to dream about exploring jungle...
Love the shirt! Photosynthesis is dope!
Literal leeches are more important than Pandas… jeez
It really shows how being cute matters!
Ahahah! Was not expecting that
Why would them attaching to humans directly on the skin be a contamination issue? If they're able to determine species by DNA in the blood, couldn't they just say "Oh, there's human DNA here, either a human is in the jungle or it's from the person we picked it off of"? As I was typing this, I thought maybe there would be contamination from things (animals) the human has touched, but the same would still be true of their clothes, right?
*(Twilight Zone noises)*
Just more work.
which forests is it where you wandering about gets you attacked by leeches?
Surprisingly many, but I think Hank said the study he was talking about was in Vietnam.
In places like the rainforests of Southeast Asia, the Amazon Basin, or even some areas in Australia i think
@@AncientWildTVthank you, kind stranger, for telling me a few places I don't want to holiday.😂
@@wendymoyer782 yea i think no one wants leeches to suck their blood too 😂
Makes a lot of sense, very smart, I love it. Are there any leeches that feed off leeches? Mosquitoes that feed off leeches?
Leeches are so cool, I've been thinking about getting one as a pet. Super excited about this video!
the biggest perk is that you dont even need to buy pet food :D
Not even a minute in and this already reminds me of that new method they now use in lakes or bodies of water to see what species exist in that ecosystem. Now this might be a good way to do this on land.. interesting
I used to own a variety of scavenging leech (non-bloodsucking) as pets in an old aquarium. I had air-stones, Java ferns and small rocks in there for the leeches to hide in and around. I might get some of those leeches again sometime soon!
2:55 Can leeches feed off from dead animals? Could the bat have died and fallen to the ground?
I believe they don't prefer dead animals kinda like mosquitoes. Blood tends to go bad pretty quick
A sick or injured bat could also be on the ground unable to fly yet alive
They typically aren't even attracted to dead creatures, they are attracted by markers that will not usually be present in non-living material. They tend to hunt using vibrations in their environment.
Doubtful, blood isn't flowing in a corpse. It was probably an injured bat that fell.
Saying "bitey little blood-libraries" three times fast is HARD xD
You should do more videos about underappreciated, misunderstood species like wasps!
I'm gonna need a t-shirt that has a picture of a leech with "bitey little blood librarian" as a caption
i love leeches i’m gonna get some soon to keep as pets :3
I love sci show! And yet sometimes you do videos about emerging tech and i kind of dismiss it because the results are inconclusive or the studies are in the early stages. This video is not like that, this is amazing and it clearly demonstrated not just that this can be done but that it can be done in the real world and lead to real results. I was truly amazed and enthralled, this is how i most enjoy science news!
I used to have two pet leeches. It actually doesn't really hurt that much when you feed them, it's just like constant tiny stinging in your finger (that's where I fed them), it is a pretty cool feeling though, probably because of the shape of their jaws (it's a triangle).
Mmm, tummy data!
Leeches are amazing and helped us develop modern medications too :D
I remember helping as a lab assistant doing E-DNA studies at the University of New Mexico at Albuquerque (my degree is in Environmental Science). It was super cool! By sampling hte water in the northern Rio Grande (aka Rio Bravo), we were able to find small traces of DNA from the New Mexico Meadow Jumping Mouse _(Zapus hudsonius luteus)_ and the Rio Grande Silvery Minnow _(Hybognathus amarus)_ both of which are endangered. However, we did find lots and lots of domestic cattle DNA, likely from fecal runoff. That tracks with the nitrate levels of the water being something like 10 times the normal amount. Never ever swim in the Rio Grande if you can avoid it, unless your idea of a good time is an E. Coli or Salmonella hospitalization.
Lovin the hair Hank
I want your shirt, hank! Photosynthesis IS dope! Lololol
And here i thought leaches were aquatic swamp creatures
Beautiful
Environmental DNA seems to be found everywhere someone is looking for it. Like a month ago i heard an interview with a researcher from Copenhagen University talking about collecting environmental DNA from the air. If i remember correctly they found dna from the local zoo while testing their "DNA vacuum".
anyone see the Humphrey Bogart movie 'The African Queen'?
Or The Lost City with Sandra Bullock and Channing Tatum? A very important scene where Channing has to get naked to be checked for leeches by Sandra.
I thought the thumbnail was a BBD 😂😂😂
The one time I had a leech on me, I was 9 and I screamed. Haven't been back in a pond since.
Stripey lil bunnies!
Reminds me of a study tracking when and where early hominids lost their fur...via lice!
I live in north central Arizona, not much problem with leach's here.😆
Could y'all do a video about assistive reproductive technology (ART) for toads? Idk if it's a common thing but I stumbled on an article saying how somewhat recently they did "the first successful IVF on the Houston toad" and now I can't stop thinking about it 😆
How accurate is E-DNA at distinguishing between different animals? If two animals are 'close' relatives of each other, could that influence the accuracy of the results?
They said at the start they look for specific snippets that are unique
leeches are awesome!
It's basically the plot of Jurassic Park, just a bit leechier
LOVE FROM PUNE INDIA🇮🇳🇮🇳🇮🇳 ❤🥰🙂😘😀☺😊😍🥰❤🥰❤❤
So.... lets talk about what the thumbnail looks like
NO FOR REAL LIKE WTF
I confused... I always thought leeches only live in water. In movies they are always found in swamps or something like that. I didnt't know that they can also be found on the ground or on plants...
Hi Hank!
Have scientists measured how high leeches can jump? If they can jump pretty high, that may explain how they are able to connect with bats and birds.
Do not confuse Hirudo (a leech) with Hirundo (a swallow).
The timestamp covers up the end of the title in the thumbnail
Leeches can leech on other leeches?? Huh. That's like saying clowns hate clowns.
Woop
Annamite striped rabbit? I've never seen a rabbit with that kind of coloring anywhere else even anything like it even domestic rabbits.
Sure there's patchy black and white, grey, tan etc. and rabbits with black noses and ears but no strips like that. I wonder what rabbit breeders that show rabbits think? Do they want one. Do they wants to try with domestic rabbits to breed strips into a rabbit as a new breed?
The picture is of a taxidermied Sumatran striped rabbit, which is closely related. The Sumatran striped rabbit is so reclusive that the locals don't have a name for it and did not know it existed. The locals only know foreign rabbits. They are too distant from ordinary rabbits to breed with them, even if you could find any.
Did they find a Rock Ape (Batutut)?
Were they around with the dinosaurs? Jurassic Park remake?
How did a leech get into a bat? Flying leeches? I'm scared.
Nah, probably because the bat took a bath in the water where the leech lived. A lot of leeches have chemicals in their salive that make it impossible to feel a bite, so the bat probably just didn't notice.
@@sophiejones3554 Oh, that makes sense. Bats need to drink water too, yeah. My comment was half joking anyway (I know leeches don't fly) but this makes sense.
Forest leeches live in trees and underbrush and drop/"jump" on things passing nearby. Like ticks, only squishier.
Some bats will sleep in tree hollows (like many types of birds and squirrels)--caves simply aren't very common where the underlying geology isn't limestone. I imagine a tree leech might encounter such critters during the bat's daytime rest, though the pictures of arboreal leaches that I have seen usually have them out on the foliage (to better latch onto passing animals?) rather than on trunks where nesting holes are more likely to be found.
never knew there where NON WATER BASED leaches
I hope the research assistants were paid extra…
Leeches creep me out. There aren't many creatures that do, but I just can't with leeches.
goated leeches
Yea! Hank is back.
Can we potentially find out about the existence of a new species by finding unidentified DNA?
Also, mosquitoes are much more common than leeches, could they be used in this way too?
At first glance, this thumbnail does NOT look like a leech. I def saw a certain male appendage at first 😂
BBC baby! I thought was on the wrong site for a sec.
Your new hair is so cute! I'm so glad you are still with us to explain all this science!
All else aside leeches are at best mildly annoying for humans, but if a leech comes across a shrew does it just suck it dry in one go? Or are there smaller leeches that go for smaller animals?
At worst, old people have died from multiple leech attack when working in rice fields.
👍
you've proud hair now, you seem fine !
For months?!
I gotta tell ya, your hair just keeps getting better n' better.
btw, I did pay attention, I promise.
Save me, daddy.
Ah yes, the science every child dreams of doing: walking around so leeches stick to you 😂
I wonder if this process has uncovered DNA we were unfamiliar with leading us to find animals we didn't know lived there or existed.
Im kinda dumb, but red blood cells don’t have a nucleus so where is the DNA coming from?
Terrestrial leaches??!
I’ve heard leeches are good for hemorrhoids 🤔 interesting mental image for you
I think we should be careful looking at data like this. As is often said, correlation is not causation. For instance, researchers noticed fewer wild animal DNA in leeches near reserve borders and more livestock DNA. With that, they assumed wild animals must be denser farther from these borders. Although this very well may be the case, this is far from the only reason this could be. We know that parasites have a tendency to specialization, specifically to their host species. Just introducing a large population of any one animal, like thousands of sheep, will trend parasites to that more common species. Population numbers of wild species would not need to change. Perhaps, wild animals are better at avoiding leeches or just better at detecting them once on their bodies. Maybe the best grazing land is also the leech species preferred environment. There are so many other reasons beyond wild population declines that could bring these results, many being just as if not more plausible. To be additionally clear, I'm not saying their conclusion is incorrect. It may be correct, but the evidence provided so far doesn't actually say that. It just says in areas with more domestic animals, leeches eat more domestic blood. Anything beyond that, without looking into host preferences in the local populations, is just speculative of a correlation.
Absolutely, correlation is only the first step, but if they have a diverse sample in terms of types of leeches and locations gathered within an area, you can get a pretty whole picture. Also, I'm pretty sure leeches are pretty non-picky, at least as a whole, so while species A may have a slight preference for sheep over deer, species B-ZZ37 would probably balance it out.
Comments before me, commented first and then watched the video
Suggestion. Ad placards should probably be up high. Even though I can hear, I have closed captioning on and the placard overlays the CC.
Do leeches of different species feed on other leeches? I was picturing in my head a leech centipede but that's too wild.
Seems like thats a yes, he mentions it at 5:20
Yep, but not how you would first think. He noted "Predatory" leeches, which have a far more conventional "hunt, kill, eat" relationship with other leeches.
I think leeches are cool, I’d love to keep a few of them as pets.
How would you keep them fed, tgen?
Scientists: "Bat DNA? Wasn't expecting that!"
Leech (to its friends): "So I was feeding on this furry thing when, I kid you not, it just took off! There I was, just dangling along, getting my fill, and this thing's going all over the sky! Leech, I nearly fell off it. It finally landed and I was like, nope, not again, never biting one of these, no matter how hungry I am."
If there is any way to find Sasquatch...
Remember when this guy had straight hair? (If I'd a consistent job, SciShow is the one I'd subscribe to. )
Very clever...
...environmental DNA can be amazingly useful, but as it can hang about in colder environments for up to 50k years it doesn't say much about what's going on now.
A slightly silly "I wonder..?" Might this turn up any surprises? eg: suggesting unknown / presumed extinct species?
🤚
This could prove the Thylacine are alive.
We have to work with nature to protect nature
Do they have to kill them to derive the dna from the leech…?
I suspect that bat must have got either knocked out of the air, or maybe it was disabled/interfered with and smacked into branch, or just died and got made into food before the corpse cooled down.
I'm sorry, did you say *TERRESTRIAL* leeches?! WHAT?!?!
If leeches get blood from a diseased animal does it affect them the same or can they live through it?
So…are there terrestrial leeches in Tasmania? Because if there are, I’m seeing a new method for looking for the thylacines.