In the last decades, the invasive Prussian carp, Carassius gibelio, has been detected in most of the European countries. The Prussian carp has been undetected in many European countries since it is morphologically indistinct from the long-established goldfish Carassius auratus. In this study, genetic markers were used to identify the Prussian carp in several locations of the Iberian Peninsula (Portugal and Spai...