The Diversity Of Microbe And Zooxanthellae In Favia Favus At Different Developmental Stages

Coral reefs are the most biologically diverse ecosystems in the oceans.Reef-building corals are the fundament of coral reefs and have the most important ecological function.Favia favus is one of the most important reef-building corals in the South China Sea.The sexual reproduction of Favia favus was investigated in this study.We recorded the embryonic development process and the major changes in the process of larvae attachment.The fertilized egg developed to the larvae in 25 hs.The larvae began to attach on the 8th day.During the attachment period,the larvae experienced two major deformations,firstly the formation of the mesentery,and finally the formation of tentacles.These results revealed the early development of larval attachment in Favia favus,which helps us to understand the developmental changes in the early life of reef-building corals and provides a theoretical basis for the ecological restoration of coral reefs.Corals are complex assemblies of coral hosts,symbiotic zooxanthellae,microbe,and fungi.Coral symbiotic microbe communities are closely related to coral health.Symbiotic zooxanthellae is the main source of energy for building coral reefs.We compared the diversity of symbiotic microbes in the egg,larva and adult of Favia favus,and explored the acquisition strategies of microbe and zooxanthellae.The results showed that the symbiotic microbe and zooxanthellae may be obtained by horizontal transmission from seawater,rather than vertical transmission.The 4-d larval larvae of Favia favus have relatively high microbial diversity,but no symbiotic zooxanthellae.The community of microbe in the adult of Favia favus is significantly different from the larvae,which may have changed during the later development of larvae.The symbiotic zooxanthellae in Favia favus is C1 clade zooxanthellae,which is probably obtained from seawater during its development stages.This study revealed the diversity of symbiotic microbe and zooxanthellae in different developmental stages of Favia favus and helps to better understand the relationship between corals and microbes...