This doesn't sound good to me. Stomatopods do not usually lie around on their backs for days prior to molting. With a healthy molt, you typically see increases in digging and aggression a few days prior to molting and the last day or two they can't strike, but not the behavior you describe. If it were me, I would tend to the tank with a partial water change being careful not to stir things up and matching the salinities between the old and new water.
Roy
|