What is this plant?

What is this plant? The guy at the fish store gave it to me for free. It was in water crystals (in a tube) and I have no clue what it's name is. I have been doing some research but there are too many plants that look like this one. If you know please help.

It has been changed for the better

I have changed the way my blog looks. I hope you like it as well as I do. Please don't let all the black change the way you think of me. I just think that black made every thing light up.