Brazilian flathead is a coastal species distributing from Southern Brasil 23ºS to 47ºS in southern Argentina. In the Bonaerense region, there is enough evidence for differentiating two biological stocks separated by paralel 39ºS (Rico 2010):

• Bonaerense north stock at the ZCP of the CTMFM between 34ºS and 39ºS
• Bonaerense south stock at "El Rincon" in the province of Buenos Aires, between 39ºS and 42ºS

The current profile focuses on the northern stock, which is within the CTMFM jurisdiction, and it is assessed and managed by this agency (CTMFM 2020).