Neocaridina Parasites?

[KatieBug2k6]

I recently got six assorted neocaridina. I have had them for about four days now. Two days ago one of them died. He was perfectly fine outwardly and behaviorally. I was actually more concerned about one of the others because he wasn't moving much, but it turns out he just found something really good to eat. The shrimp are in a 3.5 gallon tank that has plants, and lots of hiding spots. Everyone has been eating and going about their business like normal. But today, I noticed little white worms. They are very active and are burrowing in the sand of the tank, and there are quite a few of them. I know they aren't detritus worms since a 10 gl tank my family has, has had them show up in the past. I do have some experience with shrimp and parasites. I have had some ghost shrimp with horse hair worms (that's what my family and I thought). These worms look similar to those but I don't think that's what they are. All my shrimp are behaving normally. If you need more information I will be happy to provide it if I can figure out what this is.

Bonus: Under a microscope

 

[richiep]

Thats got a segmentive body which I think is a type of Midg larvae

 

[KatieBug2k6]

I got my water tested and the worms checked out at the store where I got the shrimp. The employees told that they're nematodes! So basically, like detritus worms, they clean up the extra food. I'm not quite certain this is what they are, since they are segmented, and one of my shrimp has an unusual white spot inside of him, but hopefully that's what they are!
They most likely came in on some of the rocks I got from my backyard, and I just didn't boil them long enough.

 

[richiep]

They are not nematodes as far as I'm concerned
The only worm to get into a shrimp body is planaria

 

[KatieBug2k6]

You're right. I had another shrimp die today, and I have no idea what happened. He could have been old, since he was quite big, but bigger than the first shrimp to die. I've already done a 20% water change, and I'm cycling another container in case they need to be moved.