What have you seen

Just had a weird thing happen - still not 100% sure.

I have had two emerald crabs in my tank for 3 months - on Wen I noticed that both crabs turned white and stayed in one spot. Very close to each other. So I was thinking they both molted - but the next day one of the crabs were on the sand and about ten nusaruiss snails were going to town. I have one molt (almost positive) the other don't know. I have not seen any crabs since.

The real question is what creatures are most sensitive in our tanks.
anemone
cleaner shrimp
snails
hermit crabs?

Parameters
0 ammonia
0 nit
420 cal
mag 1210
ph 8.1 (day time)
ph 8.0 (before lights)

Any insight? No other creatures are dead or any noticeable issues

 

Anemone is most sensitive. I don't know about the crabs though

 

In my opinion, hermits, crabs and snails are more sensitive to the common issues like swings in pH and SG.

An established anemone like a LTA or BTA seem to be less bothered by those swings, if they are within reason.

 

Hmmm... I could be wrong, but I don't understand why they would turn white unless the crab was no longer in the shell. IME, when a crustacean molts, it usually hides in the rockwork for a few days. If you're uncertain, remove the "crabs" and check whether or not they're just the molts.

 

so if hermits and crabs start to die - chances are things are not good