(Don't) Hail Hydra!
So I've never had hydra before but today I realized they're in at least two of my tanks, hanging off the pre-filter sponge. The way they move is... creepy. I read they can get up to an inch big but these are still small. However, I'm worried about possible shrimp fry in my one tank. In that one I have betta, a nerite, chopstick snail, and wild type neocaridina. Are any of them in danger? Will they sting/harm my tank occupants? In the other tank I have a betta and chopstick snail, no shrimp. Both are medium-moderately heavy planted tanks. I'm not sure how these creatures got in both tanks, though I'm concerned if they got in more, since one of my other tanks is a shrimp breeding colony.
I know dewormer will kill them, or one can wait for them to die out when their source of micro-organism food is gone (unless they're herbivores or photosynthetic?). Though I also read they're a natural part of an established ecosystem like nematodes, seed shrimp, and planaria. Do I keep or react?
Edit: One of them has tentacles half an inch long. Can these actually sting me? ..Okay, it's actually extended its tentacles to an inch long.
Last edited by Ryan Mosby; 11-01-2019 at 09:58 AM.
Reason: terrifying edits