Yes they are, they are a mix of Marone saxitilis (this one, striped bass) and Marone chrysops (white bass) I believe they call them whiterock bass. I don't think M. saxitilis can live and breed in only freshwater, I'm pretty sure thats why they needed to hybridize them. While I don't know how big the hybrid can get, I do know that a pure M. saxitilis in the wild can reach 50lbs/50inches.