Orangespine Unicornfish

Photo: Matthew Bokach · CC BY-NC

Orangespine unicornfish graze algae from the lava flows in loose aggregations, their twin bright orange blade-like tail spines flashing warning to would-be attackers as they feed. As herbivores on volcanic substrate, they perform the critical function of removing algae from newly deposited lava, creating cleared surfaces where coral larvae can settle and begin reef-building. Their bright coloration and calm feeding behavior make them easy to observe and photograph in the shallow surge zones.