The requirements concerning the organisation of the markets in fishery and aquaculture products are established in the Regulation (EU) No 1379/2013. 
According to this regulation certain type of fishery and aquaculture products which are marketed within the Union, irrespective of their origin or of their marketing method, may be offered for sale to the final consumer or to a mass caterer only if appropriate marking or labelling information are provided, among others: 
-  the commercial designation of the species, 
-  the production method,
-  the area where the product was caught/ farmed, and the category of fishing gear. 

Member States shall draw up and publish a list of the commercial designations accepted in their territory, together with their scientific names. 

In case of Poland, the list of commercial designations of fish species is published and updated by The Ministry of Maritime Economy and Inland Navigation. The food business operator, who wishes a new species (not included in these lists so far), to be placed on the market of the target country, is obligated to ask the proper authority in the target country to add that species to the list.

Source:Ministry of Maritime Economy and Inland Navigation of Poland