Well a few weeks back i set up a brackish tank for my fiddler crabs. I put a bunch of crushed coral in it. I just noticed that their is about a 1.25cm little fish their. I put some fresh hatched brine shrimp. I am not sure what I should do I wanna keep him. But I gess that he is a saltwater. I gess that their must of been an egg in the coral or on my fiddler crab. What else can I feed him.