New crabs look lethargic

[CrabbyMomma77]

We have a new tank, and had one crab died. Heartbreaking. The two, very active once I picked yesterday, are acting lethargic today. Temerature and humidity look fine... Please help!!

[Crabber85]

Sounds like Post Purchase Stress or PPS which is a common affliction of newly purchased hermitcrabs and is caused by the stress and malnutrition that the crabs faced in the months that it took them to find their way to you.PPS actually starts when the crabs are first harvested where they receive very harsh treatment and very bad care, they are then brought to holding facilities where they await distribution to the various stores that will be selling them and during this time they are live cram packed with hundreds sometimes thousands of other hermitcrabs in tiny holding rooms.Since they are in such tight overcrowded quarters and receive little in the way of nutritional care they tend be very stressed and as stress lowers their immune response they easily fall victim to bacterial and fungal infections that they would have otherwise been able to fight off.Add being sick from poor care and overcrowded conditions to the fact they have had to postpone molting for months because they haven't been able to find suitable conditions they are in very bad shape by the time they reach us and most newly purchased hermitcrabs don't last long once home with us.When a hermitcrab postpones a molt it produces a hormone in its eye stalks called poly peptide neurohormone this molt inhibiting hormone or MIH will continue to be secreted as long as the crab can't find suitable conditions to trigger the molt inducing hormone ecdy-steroid and the MIH will eventually build up to toxic levels saturating the crabs body either throwing it into a surface molt or just outright killing it.This is why a four week isolation period is so vital to improving the initial odds of survival for newly purchased hermitcrabs.During the four week iso period you should be hands off as much as possible only disturbing the crabs to change out their food and water but other than that no handling should be done this will give them the highest chance at being able to molt successfully and reduce any possible stress.It is important to note that during the first two months with us the crabs can succumb to PPS as it has long term effects on them that go way past their first molts with us so loosing newly purchased hermitcrabs even after two or three months is not at all uncommon and is unfortunately unpreventable as we can not reverse the damage that has been done to them before we got them.What size enclosure are you using?What kind of substrate do you have and is it dry or sandcastle consistency?What foods have you been feeding them?What kind of water have you been using for them if tap are you using a dechlorinator?