No one ever talks about the poor old damsel fish. But they are very important in the reef ecosystem, eating algae allowing for reef regrowth. Damselfish are one of the most abundant groups of coral reef fishes. They display remarkable diversity in habitat preferences, feeding habits, behaviour and colouration. Most species are highly territorial. Algal-eating species zealously defend their ‘plot’ against intruders, regardless of size. These algal feeders. These algal feeders generally have drab colour patterns whereas the plankton-feeding damsels are brightly coloured. Damselfish eggs are laid on coral rock and are guarded by the male until they hatch in 2-14 days. All damselfish, except the anemonefish (genus Amphiprion and Premnas), change sex from male to female. The anemonefish goes through a reverse sex change from male to female.