Four things happen in this step. Firstly, the leading edge of the right side fin (top left image inset) is drawn – note how there are two thin bands of highlights along either side of the dark band. Secondly, another small tail fin is added to the rear section of the body. Because of the perspective, we can only see the leading edge and the whole thing looks kind of strange (bottom centre inset). Thirdly, we start to shade the gills (bottom right inset). Leave thin bands of highlights at the bottom and top of each gill, but not in the centre. You should also define the gill borders at the bottom and top of the gills, but again not so much in the centre. Finally, darken the outline of the eye (top right inset) and shade it as shown. Note the small oval of paper that is not shaded at the top of the eye.