Arrow crab loves his snails

[reptifish]

i recently purched 12 turbo snails to help clean my tank. The next day i noticed mayn were not movieng i removed them from the tank noticing they were gone from their shells. that night i noticed my arrow crab moving another snail to his rock where he was eating all of my snails. is this common for them to do and is there any thing i can put in that he wont eat

 

[motohead]

i had an arrow crab that grew to the size of a softball(his leg spread).he was a murderer that took out three fish,a flasher wrasse,a firefish and a bar goby.watched him do the last one.murderin bastages they are.i suggest you get rid of it.lol

 

[reptifish]

lol if he hurts one of my fish hes meeting my puffer in the other tank