Public domain photos

The image shows a freshwater mussel on a gray surface with a ruler next to it. The mussel is a light brown color and has a smooth, glossy texture. The ruler is a standard measuring tool with a black and white color scheme.

The image shows a freshwater mussel on a gray surface with a ruler next to it. The mussel is a light brown color and has a smooth, glossy texture. The ruler is a standard measuring tool with a black and white color scheme.Open in library