I need some info about my Black Calvus. Recently one of the smaller ones has taken up residence in a shell that was normally in the biggest ones area. She(I,m assuming it is a she) stays very close to the shell, and in it most of the time. He(again, I,m assuming it is a he) looks like he is guarding the shell. Is she guarding egg in the shell? She is only 2inches max., is she big enough to breed? He is about 31/2inches. How long until the eggs hatch and they become free swimmers? Will thy eat the fry? Thanks.