If feeding a freshwater fish to a mantis can cause liver problems, what about brakish fish? A lot of brakish fish are fairly cheap & do well in salt tanks. Take Molly's for instance. Great fish to cycle a new salt tank with & cheap enough to get 5 to 7 for the same price as 1 damsel. If a brakish fish living in salt water is fed to a mantis, would this decrease the chance of liver damage?