Crab molted above substrate and died

[shugoryuu]

My crab which I've had for 6 years recently molted and died almost immediately.

I have had the same depth of substrate in the tank (mix of sand and coconut fiber) for the entire time I've had him and he has molted successfully several times before. Though I've been reading that he should have had 6 inches of substrate and I only had 3 in the tank. I have a glass lid, 30 gal tank, high humidity, temp typically 80-85 degrees, fresh and salt water available, and he has been eating the same hermit crab food pellets for all six years I've had him plus occasional supplemental foods. He has never had any problems before this.

I noticed after he molted that he turned almost bright white. He seemed okay at first and I didn't touch him to avoid harming him, but I did see him move his legs. There is a shed exoskeleton next to him and when I looked at him today he has shriveled up like all the water has evaporated from his body and looks quite dead.

Any idea why his molt might have killed him this time?

[Hermiesguardian]

I'm so sorry for your loss. Sometimes even though all the conditions are right, they had damage done before we get them that eventually kills them. And as you said your conditions and his diet weren't perfect. And the effect builds up.

[curlysister]

It could be an accumulation of less than ideal conditions and improper food. In the six years, he must have grown quite a bit, so would need increasingly deep substrate to molt properly. Six inches is the minimum, or at least three times as deep as your largest crab. Pellets (ie- commercial food) is not safe for crabs. What brand of dechlorinator and salt do you use for water? Is your substrate sand castle consistency?
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