My giant leeches!

[Scythemantis]

As one of my top favorite animal groups I was pretty thrilled to learn just how easily leeches could be kept. Bloodsucking leeches can be fed congealed animal blood from the meat market, only *need* food a few times a year and thrive in nothing but standing spring water, in a jar or fishbowl with netting on top!

I have Hirudo manillensis, the "giant buffalo leech" capable of growing over a foot long. None of them got that massive since they do grow bigger and faster when they're fed directly on a live host, and that starts to get a little painful as they get larger...though I did do it for some of the babies, which gave them a massive size boost in only a week or two.

Video comparing their growth after one year:

My adults burrowing under gravel:

Some of my babies slinking, swimming and walking around their haunted house:

An adult exploring the more bioactive tank I made:

Genuinely the best pets I've ever had between their ridiculously low maintenance and how active they are. I love animals just as much if all they do is sit around all day, but leeches explore their enclosure more like very strange fish.

It took a couple years for me to start getting viable babies out of them, but I'm up from four leeches to twenty and just got another batch of live cocoons ready to hatch, I'll probably have too many this year and need to start sending them to new homes!

 

[basin79]

As one of my top favorite animal groups I was pretty thrilled to learn just how easily leeches could be kept. Bloodsucking leeches can be fed congealed animal blood from the meat market, only *need* food a few times a year and thrive in nothing but standing spring water, in a jar or fishbowl with netting on top!

I have Hirudo manillensis, the "giant buffalo leech" capable of growing over a foot long. None of them got that massive since they do grow bigger and faster when they're fed directly on a live host, and that starts to get a little painful as they get larger...though I did do it for some of the babies, which gave them a massive size boost in only a week or two.

Video comparing their growth after one year:

My adults burrowing under gravel:

Some of my babies slinking, swimming and walking around their haunted house:

An adult exploring the more bioactive tank I made:

Genuinely the best pets I've ever had between their ridiculously low maintenance and how active they are. I love animals just as much if all they do is sit around all day, but leeches explore their enclosure more like very strange fish.

It took a couple years for me to start getting viable babies out of them, but I'm up from four leeches to twenty and just got another batch of live cocoons ready to hatch, I'll probably have too many this year and need to start sending them to new homes!

I love leeches. For me they very much play on the whole "Hollywood sci-fi" thing. Or more accurately Hollywood has massively borrowed from the world of inverts.

I do know there's a leech (tiger?) that feeds on crabs. Are there any that would live off crickets/locust/roaches or do they not have enough liquids?

 

[Scythemantis]

I believe there may be some small leeches that would opportunistically attack some insects, but yeah, larger ones need large food! Predatory species also tend to be shorter lived with faster metabolisms, the bloodsuckers having adapted out of necessity to wait long periods between meals.

 

[basin79]

I believe there may be some small leeches that would opportunistically attack some insects, but yeah, larger ones need large food! Predatory species also tend to be shorter lived with faster metabolisms, the bloodsuckers having adapted out of necessity to wait long periods between meals.

This is going to sound odd but I have to ask now I've thought about a foot long leech. How many adult Hirudo manillensis would it take to drain a human of their blood?

 

[Scythemantis]

A lot of people wonder that actually, and we know someone can die after losing two to three liters of blood depending on their body size. Whether leeches could do it is a good question, because perhaps they'd get discouraged and stop feeding once the blood started to run to thin for them, but if they drank enough for it to get that bad perhaps it would already be too late? There's also the fact that their anticoagulants cause a bite wound to freely gush blood for up to 24 hours.

Maybe a dozen full size giant leeches could make you pass out I'd guess, and then even if they let go, you might bleed out from all the bites before you ever wake up.

 

[basin79]

A lot of people wonder that actually, and we know someone can die after losing two to three liters of blood depending on their body size. Whether leeches could do it is a good question, because perhaps they'd get discouraged and stop feeding once the blood started to run to thin for them, but if they drank enough for it to get that bad perhaps it would already be too late? There's also the fact that their anticoagulants cause a bite wound to freely gush blood for up to 24 hours.

Maybe a dozen full size giant leeches could make you pass out I'd guess, and then even if they let go, you might bleed out from all the bites before you ever wake up.

Thank you. Although I did know leeches possess anticoagulants I didn't realise the effect lasted that long. I wonder if this is so any bacteria is flushed out after they've fed so their blood banks are left healthy?

 

[BepopCola]

These are amazing.
How often do you change their water?

 

[Scythemantis]

Every couple weeks for the ones in jars or bowls, maybe only monthly cleaning for the bigger tanks. They can go a lot longer before it bothers them, in the wild they might hang out in just a mudhole

 

[Arthroverts]

Good to see you're still around @Scythemantis!

Impressive collection of leeches to be sure, I would definitely be interested in acquiring a specimen or two from you.
You mention cocoons...how exactly do these creatures reproduce?

Also, off-topic, but do you still keep slugs?

Thank for sharing,

Arthroverts

 

[Scythemantis]

I do still have several slug species, but still haven't perfected keeping banana slugs happy. Even living in an area where they're wild now, they don't like it indoors and begin to shrink in size. Currently trying a setup similar to poison dart frogs that stays misted and moist for them in an air conditioned room.

Anyway, leech reproduction! These are cocoons:



Each is formed from a frothy slime that eventually hardens, the spongy exterior the result of tiny bubbles in the slime breaking. Inside each is a dense blob of nutrient-rich mucus that works like an egg yolk and 3-10 developing embryos.

After mating only the larger of the two leeches will become "pregnant," and will only produce a cocoon out of the water in moist, dense substrate; in captivity what universally works is long fiber sphagnum moss, and it's easily accessible to them in a plastic soap dish:



The cocoons have to stay out of water in wet moss in a humid environment so I just put them in a smaller container with gauze on top in the same soap dish. The first viable one I ever got, I found partly hatched and put in water to encourage them further (not necessary but I wanted to film them)

Leeches are in fact air-breathing and can't remain completely submerged.

 

[schmiggle]

Predatory species also tend to be shorter lived with faster metabolisms

That's interesting, I wasn't aware.

I've always liked leeches, and these are great pictures and super cool individuals. I'm surprised they swim around so much. Have you ever had an issue with them attacking each other? I feel like I saw that once somewhere

 

[Scythemantis]

Leeches around the same size will almost never attack each other if they're all fed together, but a hungry one might attack one when it's still full of blood, and much smaller ones may mistakenly bite larger ones if they're fed at the same time!