If you’re drawing digitally, you can create a new layer and refine the lines of your fish as you fill in more details. For example, Whitlatch adjusted the top of the tuna’s head above the eye. “I added the spines to that front part of the dorsal fin. Those are very sharp spines and the fish can raise and lower the dorsal fin using those spines,” Whitlatch says.
For her tuna, Whitlatch added more soft lines to give texture to the other fins and detail to the triangular spines. She also adjusted the fish’s mouth by adding detail to the lips and drawing another curved line to represent the cheek. For his Moorish idol, Braun extended the dorsal fin triangle to a long point trailing behind the fish. To represent the delicate, transparent fins, Braun lowered the opacity of his brush to around 40 or 50% to achieve that look.
If you want to capture the individual scales of a fish, study your reference images. You’ll find that fish scales vary in size, shape, and color. Remember that they overlap and follow the contours of the fish’s body, with scales near the head larger than those near the tail.