I am giving away my lizard and want some fish. I want easy-to-care-for fish but interesting ones. I found some sharks at Wall-Mart and like them a lot. I think they are called Balla Sharks they are Grey with dark black stripes on their body and their fins, and mouth are tipped black also. They get to about 8-9inches long I think. They are really interesting they are fresh water sharks they live in groups or that is how they are housed at wall-mart I am really wanting to get some I think my tank is big enough it is 15gallon wide and long and 30gallon tall. any help would be appreciated.