Easter Island Chromis (endemic)

Photo: Maibe Hermoso · CC BY-NC

Randall's chromis is an Easter Island endemic found nowhere else in the world, forming dense schools around the upper pinnacle and reef structure in water as shallow as 5 m. It is a planktivore that feeds in the water column above the reef and retreats to shelter among coral branches when threatened. Its presence is a biological signal of Easter Island's remarkable isolation — the island has the highest proportion of endemic marine fish species of any location in the Pacific.