dead cray fish

Question
my cray fish turned whitish and stayed put in one spot for a day or two then was totally devoured the next day i have three silver tipped sharks about eight inches long two plecos four inch long two koi three inchs long two cory two inchs long and had two cray fish down to one now in a one hundred gallon tank a week ago i found the first shell but both were alive so then i found the second cray fish shell on  bottom of tank but along with the shell he was dead and the koi pecking at the remains my question is is this going to be my cray fish demise

Answer
There is no way to tell for sure.  Your fish could rightly kill the crayfish, esepcially since the sharks are so big.  But also remember that your crayfish shed their shells as they grow, so is that what happened maybe?  After they shed their shells, they usually hide until they harden back up.  If he is in fact dead though, I can bet it's the fish doing it, and you may not be able to house the crayfish in that tank anymore.

Good luck!!!    ;o)