r/leeches Jul 28 '26

ID Request Leech ID? Came with live blackworms from my local fish store.

Thanks in advance!

These were bought in Miami, FL if that matters. And were being held in a freshwater tank full of blackworms. I bought some worms and found these guys.

What do I do with them? Will they harm my fish, shrimp, and/or snails?

I found a total of 8

Upvotes

7 comments sorted by

u/iFafnir Jul 29 '26

This would be Helobdella serendipitosa (described as Helobdella serendipitous). It was described from black worms sold at a pet store in NJ. If the black worms near you come from the same source (California, supposedly) this would likely be the same species.

u/chingandoporahi Jul 29 '26

Thank you for the name!

u/irradiatedsnakes Jul 28 '26

thatd be a snail leech, not harmful to fish, definitely harmful to snails, probably to shrimp as well.

u/chingandoporahi Jul 29 '26

I suspected snail leech. Thank you!!

u/RandyButternubber Jul 28 '26

I’ve seen these guys! Usually it’s a specific species of leech that eats blackworms which is why they’re in the blackworm orders. I don’t think this species eats snails as I used to have a lot and they never touched them. As for shrimp, the opposite seemed to be true. I saw two of my neocardina tearing one apart.

To be safe you can put it in the freezer which is generally how you euthanize invertebrates as it basically knocks them out before killing them. Personally I just throw them in with the worms, my fish will eat them/they’ll live in the tank as oart of the little artificial ecosystem

u/chingandoporahi Jul 29 '26

I think I may start a feeding frenzy, then when they’re all at the front of the tank throw them in one by one so I can make sure they get eaten. Feels like a waste to just kill them if they can be extra protein for my fishies

u/RandyButternubber Jul 31 '26

They might escape and reproduce in the tank but luckily that just means more food for them too. Plus they’re often hidden too so you won’t see five billion leeches everywhere either