Shrimp diseased

[Maggie]

Last week I thought they were all fine, but were hiding more than normal. I haven't added anything but plants to this aquarium (plants were quarantined for 2 weeks). Today none of them can swim and they keep having sessions of jerkiness followed by sinking upside down to the bottom. All fish are fine, even my remaining danio fry.

Temp 73.5, pH 7.4, NH3/4 0, NO2 0, NO3 <10, GH and KH both 7. 

Is it possible they had this when I got them in October, and it's taken this long to show itself? I'm not sure what to do for treatment. It's very stressful to watch them try to swim and they can't. 

https://youtube.com/shorts/Be7AVs6jrJ4

 

[Hobbit]

Not sure what it could be but following to learn. It seems neurological... I wonder if it’s a genetic defect in their strain that takes some time to show?

[Maggie]

Here's another one - this is what they do if they try to swim. Shrimp videos on YouTube suggested a salt dip (1 TBSP in 1 cup of water for 20 seconds), so I did that on 3 I could catch. If it helps I'll be able to tell, as right now none are able to swim. 

[Ken]

Just shooting from the hip here. I wonder if there is such a thing as a whirling disease that infects invertebrates? If so an anti-parasite treatment might help. 

[Maggie]

It's very strange that today they are seemingly back to normal, but I think I lost a few. No idea what could have caused this.

[Hobbit]

Weird. Well, it will be interesting to see if it happens again. Maybe it was a pathogen just passing through?