The bastard sturgeon, fringebarbel sturgeon, ship sturgeon, spiny sturgeon, or thorn sturgeon (Acipenser nudiventris) is a species of fish in the Acipenseridae family.

Among these are an exceptionally high diversity of sturgeon, a total of six species (beluga, Russian sturgeon, bastard sturgeon, sterlet, starry sturgeon and European sea sturgeon), but these are all threatened and have largely-or entirely in the case of the European sea sturgeon-disppeared from the river.