The Blue Green Damsel Fish (Chromis Viridis) is native to the coral reef systems of the Indo-Pacific Oceans. They live in large shoals of up to one thousand members living in and around branching corals like Acropora which they use for protection from predators even sleeping among the coral branches at night. When predators threaten or snorkelers get too close the whole shoals move as one into the safety of the coral head. They swim facing the current to catch zooplankton which forms the basis of their diet. They are the most numerous fish in the Aroa Marine Reserve and live to around 15 years old and can grow to a length of 9 cm. They breed on the sand and rubble. Males prepare the nest for spawning at dawn with several females. The male then protects the nest keeping the fertilized eggs ventilated with its fin and eating any eggs that do not fertilize.