Beware the Leapin' Leech
Aw yeah, they jump now. Maybe.
White men can’t jump. But leeches? Leeches got this. Sort of.*
Most people I talk to about leeches are only familiar with the kind that attach themselves to your ankles when all you want to do is hang out in a pond on a hot summer day. Others might be aware that leeches were, and ARE, used in medical practice (great for trying to re-attach fingers, for example).
But did you know that leeches live on every continent except Antarctica? Did you know that leeches live in the sea? In fresh water? On land?
And did you know that land leeches can jump?
If you think hard about what a leech is, it becomes clear why exactly they can do so well in so many different environments. Leeches are worms with a blood fetish (as in they are in fact both annelids), and worms do well in all these environments. They need warm, wet spaces, and those can be land, sea, or lake.
If you’re a leech on land— nice, moist land—when it comes time to hunt, you need to move toward your prey. Leeches are slow, so the options are few. Hide somewhere high up and wave your little leech neck out toward the prey and latch on. Hide higher and try to drop down on them. Hide somewhere animals are likely to rest for a while.
Or take a leap, as Mai Fahmy documented on two occasions in Madagascar.
The video is even better, you can almost hear the “wheee!” The best part is how they don’t even TRY to stick the landing it’s just a tumble.
You would think that if a leech literally up and jumped on someone, they would notice. And indeed, people have. A lot of places cite Haeckel’s tale of jumping leeches on his trip to Sri Lanka in the 19th century, but Ibn Battuta talked about them in the 14th century as well. Other naturalists have talked about leeches “falling” from high up leaves onto people.
But is it jumping? Leaping? Bouncing?
That part is controversial. What IS it to leap? What IS it to jump? A jump requires an explosion of force to propel yourself. We do this with our legs. Leeches, obviously do not have legs (if they ever get them, we are screwed) but they do have muscle. So ARE they using an explosive force of that muscle to propel themselves forward?
The scientists say yes, but others aren’t quite sure. Maybe it’s just a “controlled” fall? No one doubts that leeches can fall with nefarious intent onto a host. But is this enough effort to be a jump? We’d have to ask the leech.
Anyway, watch out in Sri Lanka and Madagascar. I hear they have leaping leeches.
Other Leapin’ Leech coverage:
Other Leech facts!
Citation: Fahmy, M., & Tessler, M. (2024). A jumping terrestrial leech from Madagascar. Biotropica, 00, e13340. https://doi.org/10.1111/btp.13340
Where have you been?
Is it looking that is fabulous beautiful amazingly preserved trilobite fossil? Scientists can even learn how they chewed, which was along the whole length of their bodies! We can all but aspire.
Is it reading this delightful physiological breakdown about how Dr. Who’s two hearts work? The worst thing about this piece is that I didn’t think of it and write about it FIRST.
Maybe it’s reading about a giga-goose. Because like, sure you think geese are scary now? Make it 6 feet tall and 500 lbs, and thank everything you don’t live in the Pleistocene.
Maybe it’s looking at the LOVELY things that result when you turn electron microscopy into art. Rotifers look like tiny muppets, a mosquito’s foot is a flower. So lovely.
Maybe it’s reading Charlotte Clymer’s newsletter, this quote resonated with me so hard:
You can be thoroughly correct—morally, ethically, spiritually, whatever—but unless you’re willing to meet people where they are and engage in tough but necessary conversations and exercise patience with those who may not see the world exactly as you do, simply being correct and having a nickel is worth exactly five cents.
Or maybe it’s reading this piece about why yes, gun violence is a public health crisis? It’s predictable. It’s preventable. And it hurts the health of people and their communities.
Where have I been?
I’m back in Scientific American with a story about a rock. It’s a rock I picked up in the Sahara. Is it a geode? A dinosaur egg? A meteorite?
As you all may know, freelancers get their income from many places. One of mine? I produce podcasts. I’m very proud to be able to produce podcasts that work for meaningful change, like this one! It’s called Diversity Dialogues and it’s from the National Academy of Engineering. And it’s about promoting better inclusion in engineering spaces. Because inclusive teams make better decisions, and engingeering as the data to prove it.
Anti-Discourse Actions
Sometimes I feel so defeated you guys. Scrolling makes me feel like everything is wrong, and all the Discourse makes me feel that nothing I can do is the right thing to do. Thank goodness for anti-discourse actions. I’m doing my best to BE change. And maybe it’s small change. And maybe it’s incremental change, and maybe The Discourse says these changes shouldn’t be celebrated as wins at all, but you know what? My action > > your flailposting.
I contacted my reps about an issue I’m passionate about.
I’ve realized I need to devote my time and effort to one major issue. Just caring and posting leaves you powerless. So I have thrown my energy into one thing I really care about, found an opportunity to move the needle, and I’m taking action regularly.
But I’m still making dog sweaters. Up to 7 in the last two months!
*Many, MANY thanks to Kelly Hills for helping me get the paper, because Wiley is just determined to keep leaping leeches from the public.