Plaque in the shape of a fish

The image shows a gray-scale photograph of a metal plaque in the shape of a fish. The plaque is curved with the head on the top right and the tail on the bottom left. The fish head features two circular eyes and an open mouth with two holes. The body of the fish has diagonal lines running along its length on both sides. A small ruler or measuring scale is placed at the bottom. The background is a plain gray surface. The plaque appears to be made of a weathered metal.