Hybridisation and introgression of eukaryotic genomes can generate new species or subsume existing ones, with direct and indirect consequences for biodiversity. An understudied component of these evolutionary forces is their potentially rapid effect on host gut microbiomes, and whether these pliable microcosms may serve as early biological indicators of speciation. We address this hypothesis in a field study of angelfishes (genus Centropyge), which have one of the highest prevalence of hybridisation within coral reef fish. In our study region of the Eastern Indian Ocean, the parent fish species and their hybrids cohabit and display no differences in their diet, behaviour, and reproduction, often interbreeding in mixed harems. Despite this ecological overlap, we show that microbiomes of the parent species are significantly different from each other in form and function based on total community composition, supporting the division of parents into distinct species, despite the confounding effects of introgression acting to homogenize parent species identity at other molecular markers. The microbiome of hybrid individuals, on the other hand, are not significantly different to each of the parents, instead harbouring an intermediate community composition. These findings suggest that shifts in gut microbiomes may be an early indicator of speciation in hybridising species.
|Original language||English (US)|
|State||Published - May 18 2023|
Bibliographical noteKAUST Repository Item: Exported on 2023-05-22
Acknowledgements: This work was supported by ARC Linkage Projects (LP160100839 and LP160101508) to M.S., M.B. and J.D.D. as well as a Curtin University Early Career Research Fellowship to J.D.D. We would like to thank the staff of Parks Australia, in particular Max Orchard, Rob Muller, Azmi Yon and Eddly Johari for their enthusiasm and support over many years of fieldwork. We would also like to thank the Christmas Island community for assisting our research, especially T. Hamanaka. We also thank Shannon Ellery, Grinnell College USA, who assisted with the lab work during a student internship and Corey Wakefield, Senior Research Scientist, Department of Fisheries Western Australia who assisted with otolith aging.