What are these bugs??!

[Tenaya]

Hey guys so I have a small 10 gallon fresh water shrimp tank. I have RCS and mischling shrimp along with another guy that I don't remember what he is. The RCS have been breeding like crazy and I haven't seen any dead shrimp but I am concerned about these little bugs in my tank. They seem to like to burry themselves in the debris and substrate or swim around in short rapid bursts. I have a very heavily planted tank so it impossible to clean the substrate. I don't think these bugs are harming my shrimp but I have recently spotted a hydra, which I am concerned about it stinging my shrimplets. I also saw a very small opaque white worm last night I believe it's a nematode but again I am worried about how it might affect my shrimplets. I haven't fed my tank in 5 days because I was hoping to reduce this pest population buti decided to put some food in today because the shrimp were getting aggressive with each other so I felt like they were really hungry because they are normally very gentle towards each other. As soon as the food hit the bottom all these bugs came back up through the substrate.
Do you know what these bugs are? Should I continue to starve the shrimp so they clear up more debris? Could this cause the bugs to attack my shrimp? Should I be worried about the hydra and nematode I found? Am I wrong about my identifications and are any of these tanks pests going to harm my shrimp? Please let me know what you guys think thanks!!

 

[Kazin]

I'm not quite sure what you have from the pictures, but I think you may have planaria. If you post some close ups I can confirm.

Fenbendazole is the only way to destroy them in my experience. You can cut down feeding, sure, but the planaria I have dealt with just start hunting shrimp when hungry. Fenbendazole will also kill off your hydra. Most people don't seem to like going the medicinal route, but I found that if you are careful with dosing there is no danger to shrimp. Cheap enough stuff online as well.

 

[Tenaya]

Thanks for the tip. I saw one of the worms on the glass the other day but I didn't have my phone on me for a picture. It was about 1-2mm in length. It was a opaque white and had a slightly darker, more tan like coloured middle. It was moving pretty fast and kept picking it's head up and moving it around like it was searching for something. I have also noticed more hydra in the tank it went from 1 to about 5 overnight. I'm not sure if one of my snails ran over one and broke it up but there is even a hydra on my snails shell! I haven't feed my shrimp since I last posted and I've noticed they are swimming around a lot and getting agressive towards each other. Do you think the aggression is related to the worms and hydra? I also might have too many shrimp in my tank. It's very hard to count how many I have because of how many hiding places they have but I think it's at least 20 now including 3 pregnant RCS. It's a 10 Gallon tank.

 

[Kazin]

Thanks for the tip. I saw one of the worms on the glass the other day but I didn't have my phone on me for a picture. It was about 1-2mm in length. It was a opaque white and had a slightly darker, more tan like coloured middle. It was moving pretty fast and kept picking it's head up and moving it around like it was searching for something. I have also noticed more hydra in the tank it went from 1 to about 5 overnight. I'm not sure if one of my snails ran over one and broke it up but there is even a hydra on my snails shell! I haven't feed my shrimp since I last posted and I've noticed they are swimming around a lot and getting agressive towards each other. Do you think the aggression is related to the worms and hydra? I also might have too many shrimp in my tank. It's very hard to count how many I have because of how many hiding places they have but I think it's at least 20 now including 3 pregnant RCS. It's a 10 Gallon tank.

Fast moving, moving its head around looking for something, opaque white - darker in the middle: You almost certainly have planaria! Does its head look an arrow point? Maybe type planaria into google images to confirm, but I think that's gotta be it.

If you do think you have planaria and hydra, I strongly recommend dosing fenbendazole, but do it cautiously. When you dose, the planaria take 3 days to fully die off while the hydra should die more quickly. The shrimp will be unaffected if you keep the dose down. There is a fenbendazole dosing regimen for RCS online somewhere.

As for the shrimp swimming around and getting aggressive, I'm guessing you saw males doing their frantic search around the aquarium looking for a female that had just molted. They will try and find the female for a few hours and then the aggression will die down. Check if there's a female that just molted next time you see them act that way and you may see them try to mate with her.

20+ in a 10 gallon isn't too many. You can fit 100 or so in there before it's a burden. Way more if it's heavily planted.

Here's a link for fenbendazole: https://www.amazon.com/Bendazole-250mg-Fenbendazole-Powder-packets/dp/B009TAQ4OI

 

[Tenaya]

Thanks for your help! Much appreciated, I was able to find some at a pet store and found directions for the product on google. Thanks again!