 Abstract corals are a diverse group of marine organisms that live in a variety of habitats ranging from near-surface waters to the deepest parts of the ocean. Despite their widespread distribution, little is known about how these animals have adapted to their different environments. In this study, researchers used a combination of genomics and phylogeny to investigate the role of mitochondria in the adaptation of coral species to different depths. They found that certain genes related to energy production were undergoing positive selection in some coral species living in deeper water, suggesting that these genes may play a key role in allowing corals to survive in these harsher conditions. This study provides valuable insights into the molecular mechanisms underlying the adaptation of corals to their environment and could help us better understand how these organisms can survive in such challenging conditions.