i have to agree there is something fishy with the tigs t1karmans had when there in a tank with rays no one can blame water quality, and a uk mag practical fishkeeping did say tigs are now captive bred with hormones , tigs also won't get 36" in captivity and if thats true id love to see one.. ive seen some pics of tigs in well ovecrowded tanks especially in the monster fish keepers books, it must be something genetic, place of capture maybe some hardier than others due to maybe interbreeding brothers and sisters maybe some tigs get trapped in the same gene pool, obviously im no expert just speculating