Damselfishes (Pomacentridae) are highly conspicuous, diurnal inhabitants of mainly reef areas, capturing the attention of many scientists. Their high diversity and the many interesting characteristics dealing with their way of life (sound production, breeding biology, sex change, farming and gregarious behavior, settlement, diet, habitat) easily explain how this group is continually kept in the limelight and is the subject of numerous studies. This book gathers the data dealing with damselfish morphology, physiology, behavior, ecology and phylogeny.It contains 14 chapters written by renowned scientists.