Bryozoan skeleton

Bryozoa are tiny aquatic animals that form colonies, each measuring a few millimetres in length. The living animal is gone but the hard, calcium carbonate compartment of its skeleton is shown here. The holes allowed food to get through to the Bryozoan that once lived inside.

Imaged using scanning electron microscopy by David Salt, Australian National University. This image has been colour enhanced.

Size: about 500 micrometres wide.