It is from the family of salmonids and it is recognizable by its rather gray dress (sometimes turning blue gray / gray green), but especially by its dorsal fin where red and brown spots mingle. So much for the common shadow.
This fish has been introduced into our rivers, it is fished in Meurthe-et-Moselle and in the Vosges. When and how is it fished? François Rouillon, from the Meurthe-et-Moselle Fishing Federation (FP54) is on Laurent Pilloni’s France Bleu Lorraine microphone.