“I found this in my swimming pool in Mobile, Alabama and I’m wondering if it’s a leech?”, asks Dean in his submission regarding the glossy, black, worm-like creature pictured below. Right off the bat, we have to agree with Dean that this does look like a leech. That said, when we zoomed in on the photo, we saw what looked like part of the creature’s underside, which was a lighter gray color. This made us think about slugs, and the possibility of this being one, though leeches also typically have lighter-colored undersides.

Between the two, we do think it more likely that this is a leech. While there are over 200 species of mollusks in Alabama, including slugs and snails, there shouldn’t be any black slugs in Alabama. Black slugs are native to Europe, and while they can be found in the United States (and are considered an invasive species), they are found in the Northwest, which obviously does not include Alabama. Besides, this creature doesn’t have any of the characteristic vertical stripes down its back like slugs do. Of course, leeches are segmented creatures, and this organism doesn’t seem to be visibly segmented. However, the segmentation on leeches is much finer, and maybe that just isn’t showing up on the photo.

Assuming these are leeches, we strongly urge Dean to avoid physical contact. Besides the fact that leeches are ectoparasites that attach themselves to one’s skin and drink your blood, they are capable of spreading viruses like HIV and Hepatitis B, and infectious diseases like malaria. If possible, we suggest fishing it out of the pool with a fishing net or something oblong that will allow Dean to avoid touching it, and moving the leech somewhere else. In this case, we would even suggest killing it. We rarely do recommend this option, but given the danger that leeches pose, we think it is justifiable in this case.

In conclusion, we agree with Dean that this is probably a leech. How it got in the pool is a mystery, though it has happened before that leeches come up through drains. We hope this helps, and we wish Dean the very best.