Ecology, Biology and Genetics of Millepora Hydrocorals on Coral Reefs

Abstract

Coral reefs are one of the most productive and diverse ecosystems on Earth. However, climate warming is occurring at an unprecedented rate and has negatively affected coral reefs worldwide. Evaluating the life history of reef-building species carries important implications for coral reef conservation. This chapter examines the taxonomy, biogeography, ecology, symbiosis, morphology and reproductive biology of Millepora hydrocorals, an important but relatively unstudied component of coral reefs. An emphasis is also placed on the influence of variable reef environments on Millepora life history traits, providing a fascinating opportu-nity to study the interplay between ecology and evolution. Special attention is given to ecological and evolutionary benefits of asexual versus sexual reproduction in the maintenance of genetic and phenotypic diversity. Lastly, this chapter discusses whether life-history strategies of Millepora hydrocorals and tolerance to different stressors can influence their ability to adapt and survive to future climate change, and other natural and anthropogenic disturbances. heavily relies on asexual reproduction through fragmentation for local replenishment (80% of the colonies are clones), allowing population growth and the persistence of a genotype over time. M. cf. platyphylla population is sustained via a significant contribution from self-recruitment (8 – 36% of juveniles are self-recruits). Mosaicism and chimerism also contribute in creating novel genotypic diversity at the population and individual levels.