08 March 2010

Heartless leeches

After last Saturday's MAM meeting at the Delaware Museum of Natural History, Megan P. and I stopped by the museum's ongoing exhibition Attack of the Blood Suckers. Megan had heard that there were leeches.

We found the leeches in a large aquarium tank. In the dimly lit hall, they looked rather drab. But the flash of my camera revealed their true colors.


Here is another one that was mostly out of the water. Despite being aquatic creatures, leeches apparently do leave the water occasionally and voluntarily. Is this one a different species than the previous one?


According to the information panel below the tank, leeches don't have hearts. But they have an anus.


Leeches are, of course, sanguivorous; they feed on the blood of other animals. We left wondering what they were feeding the ones at the exhibit. There were lots of little kids around.

Note added 24 March 2010: I have now identified the leech in the photo as Hirudo verbana. See this post for details.


Julia said...

Wow, what a great sounding exhibit, and what cool leeches. I looked at the website, and there's a video about how they make blood sausages out of cow blood for the leeches. http://www.youtube.com/watch?v=RLHnkahdWiA Yum!

Megan said...

Thanks for the video link, Julia! I was curious about how they could feed leeches (without personal sacrifice), although now I feel squidgy.

Anonymous said...

Oooo, pretty! I am no leech expert but yes, I think they are the same species. The top one shows the pale green underside of the animal, and the bottom image shows the colorful top side of another individual. I think these are big ole Medicinal Leeches, but whether they are the European ones or the North American ones I don't know.

Anonymous said...

Ooops, that last message was from was me.

Susan J. Hewitt

Coyote said...

There are terrestrial leeches that do not feed on blood but instead are predators of worms, snails and insect larvae. I have a few living in the leaf litter and damp soil of my back yard.

Paul said...

I worked with leeches during my grad work, and I am quite familiar with these guys. The two images you show are the same species of leech: Hirudo verbana or Hirudo medicinalis. There's still some confusion about whether they are separate species. At any rate, the top picture shows the leeches light green underside, with the head facing down. The lower image shows the leeches back side. I think the head is facing up, but it's a bit tough to tell without comparing the two suckers. These are "medicinal leeches" used popularly throughout the victorian age, and making a comeback in modern medicine as well. Both are European.

In the lab I worked in, we fed our leeches sheep blood, which we would pour into sausage casings. The leeches would bite into the casings and suck the blood out.

I should point out that while the common perception of leeches are the bloodsucking ones, a vast majority of leech species are predatory. There are aquatic, marine, and terrestrial species, but people aren't familiar with them, because you won't find them hanging from your back after swimming.


Paul, thanks for all that info. I knew there were terrestrial leeches, but I had assumed they all fed on blood.

siobhan said...

Hello, I tried to "click" on Paul to ask a leech question, but help from anyone would be great. I have a leech that was left over from a class we did at my work place. They were bought through Carolina Biological as Medical Leeches, but seem to be Hirudo verbana. Anyway, I feed them both last December (on my leg) and one got "kinks" in its body, shriveled up a bit, and died a week or so later [talk about feeling rejected]. The other leech, Brom, is doing well, but has developed a kink, too. It seems that there is a band constricting its body, but I can't see any obstruction or feel a abnormality. Any help/advice would be great, I can't find much information. He is a pretty cool creature, swimming around and such. Thanks, Sean