Cleaner shrimp mystery

[SkeptikalScabies]

Hi, I had a 4 or 5 year old scarlet skunk cleaner shrimp that died the other week. I found it with its back shell lifter up and it's hills exposed. The hermits had eaten most of it so I assumed it probably died milling due to its age.

Christmas Day, I got a new one. Its been pretty skittish, unlike the other shrimp. Today I found it dead with its back plate lifted up and it's gills exposed. The crabs hadn't found it so it was still in good shape. All my other inverts, fish, an coral seem healthy. And all my water parameters read optimal.
Can anyone help me troubleshoot what's killing my shrimp?

P.s. My pistol shrimp is still healthy and clicking away under his rocks.

 

[Wailua Boy]

What other fish and/or inverts are being kept?

 

[Wailua Boy]

My advice without knowing anything about your set up is be sure to supplement iodine; if you are not already. It seems to be the source of trouble for many invertebrate species.

 

[SkeptikalScabies]

What other fish and/or inverts are being kept?

I've just got a couple of various hermits, a ocellaris clown, a prawn goby, a pistol shrimp (who is alive, I saw him 20 minutes ago) a coral goby, a fire fish and some mushroom and hammer corals. Plus some cousin of Xenia corals.

Oh! I've also had an explosion of various pods and some very tiny pest snails.

 

[Wailua Boy]

On occasion pistol shrimp will kill other shrimps, a lot of times they do coexist though. Be sure you don't have a mantis shrimp that hitch hiked in on your live rock living in there, that could be a likely suspect, if so