This micrograph shows blood vessels at the back of a fish’s eye. There are larger vessels at the top left and many smaller vessels at the bottom right. They contain blood cells that either supply oxygen to the underlying retinal cells (rods and cones) or help fight off infections. The diagonal rows of round dark dots are pigment granules that absorb stray light and stop it from leaving the eye.
During dry periods, many freshwater fish retreat to water holes and damp areas where they remain until rain replenishes the rivers and creeks.

The widest part of the pigment granule layer is about 2 micrometres (1 micrometre is one thousandth of a millimetre).

Image: Shaun Collin

The painting is about a dry river bed. The big red area at the bottom is our camp – it is alive. The red water holes still have life. The red is the life blood.

Artist: Kurun Warun