Shrimp stuck in molt?

[tominator]

Hey there guys, I recently started to keep Opae Ula shrimp in a 3 gallon tank. I got 12 of them about a month ago and two weeks ago one shrimp seemed to be hunched over and deceased. Not wanting him to contaminate my tank I disposed of the body. All the other shrimp seemed fine, so I thought maybe he was a weak one and didn't think too much of it.
Yesterday I saw two more shrimp in the same position, but still somewhat mobile and today they are in the same position. They do not move, but if I put my long tweasers close to them they dart away. It almost seems that they are stuck in the middle of a molt. Again, all the other shrimp seem completely fine. Is there something I can do for them? Is there something going on in my tank? Any advice would be appreciated.

The Ph seems to be 7.8 (It's a high range freshwater ph but I believe it works for salt too)
Kh is 70mg/l (ppm)
Gh pretty high I stopped counting at 800 ppm (I guess this is never really measured for salt setups)
My hydrometer sucks, I don't trust it at all. I estimate my salt concentration to be between 1/2 and 1/3 full salt strength based off the instructions on the side of the reef salt I bought (InstaOcean).

All the other test chemicals I have are for freshwater. So I can't really test ammonia or nitrates.

P5030051 by modmyds, on Flickr

[Mustafa]

That position doesn't usually mean that they are dying or doing badly. If they are still moving around afterwards everything is just fine. Are you saying they are permanently like that? Can you shoot a video by any chance?

[tominator]

Thanks for the reply. Unfortunately one didn't make it and I removed him from the tank (completely limp and laid on his side). The other has disappeared (hopefully got over whatever was wrong with him) so unfortunately I can't take any videos of them. Those two, were stuck in the same position and in the same part of the tank for over a day and a half. I thought they were dead so I was going to use some long nose tweasers to remove them and they darted away, but would resume the same hunched over position soon afterwards.

[Mustafa]

Hmmm...that's really strange. Never seen anything like that before. As long as the rest of the shrimp act fine I guess we can simply look at it as a strange curiosity.