it doesn't look aquatic to me either. sometimes non-aquatic plants can survive under water for a couple or even a few months before they melt away. looks more like a terrarium plant to me and also like the fern i have hanging in my front window.
either way, you may want to remove the browning leaves as they will pollute your water.
they sell fake bamboo and several other non-aquatic plants as aquatic in many pet stores, the workers there aren't always educated on what they are selling. they just get paid to move product. petsmarts are notoriously bad for this.