For Round Fish with Triangular Backbone

Place the fish on a board, the head facing your working hand, that is, to the right if you are right-handed or the left if you are left-handed. The dorsal fin of the fish will be facing you.

Place your second hand over the pectoral fin and the rounded part of the gill. Holding your knife steady, make a cut toward yourself, following the side of the gill-covering plate. As you do so and as you progress toward yourself and the nape of the fish, slowly and gradually raise the angle of your blade toward the left, pushing forward at the same time until you can feel the point of your knife hitting against the backbone and your blade is at an approximate 20-degree angle.