Hitchhiker on plant id

[Mississippi fish guy]

I recently found a few of these on some plants I collected from a pond. I was wondering what this is and would it be a problem if I’m colony breeding pigmy sunfish? Also are water mites a problem because I found those in the tank as well.

[GoofyGarra]

Those are Hydras, a freshwater cnidarian micro-predator. They can be an issue with shrimplets and small invertebrates but I think fish will eat them.

[Guppysnail]

There are many types of hydra. Most are not an issue even in my hatch tanks. However there are 2 varieties I’ve dealt with that can be a problem once they become populous.  One is white the other a brownish. The tentacles are longer on those and they generally get larger. 
Your potentially look like the brown ones.  Those can nab new hatches. 1/10 (.1) gram per 10 gallons if fenbendazole clears them right up. I use it often as those become overzealous with my daily live bbs feeding. Shrimp and fish safe but not snail safe and it will be a few months until the tank is again snail safe. 
water mites=great food. 

[Solstice_Lacer]

A while ago when i had hydra on my glass i put a tiny bit of hydrogen peroxide on a sponge and wiped them off. They never came back

[DavinCantu]

Thanks for answering, I also want to know it.