[A-CG40] Coastal Ecosystems 2. Coral reefs, seagrass and macroalgal beds, and mangroves

[ACG40-06] Prediction of genetic lineages using coral colony morphology

*Guinther Hiromu Mitushasi¹, Yuko Kitano², Benjamin C C Hume³, Eric Armstrong⁴, Barbara Porro⁵, Emilie Boissin⁶, Julie Poulain⁴, Quentin Carradec⁴, David A. Paz-García⁷, Didier Zaccola⁸, Eric Röttinger⁹, Clementine Moulin¹⁰, Guillaume Bourdin ⁸, Guillaume Iwankow ⁸, Sarah Romac ¹¹, Tara Pacific Consortium ¹, Serge Planes⁶, Denis Allemand ⁸, Christian R Voolstra ¹², Didier Forcioli¹³, Sylvain Agostini¹ (1.Shimoda Marine Research Center, University of Tsukuba, 2.National Institute of Environmental Science, 3.University of Konstanz , 4.Genoscope-Centre National de Séquençage , 5.Université Côte d'Azur , 6.CRIOBE-University of Perpignan, 7.Centro de Investigaciónes Biológicas del Noroeste, 8.Centre Scientifique de Monaco , 9.Centre National de la Recherche Scientifique, 10.Tara Ocean Foundation, 11.Station Biologique de Roscoff , 12.King Abdullah University of Science and Technology , 13.Université de Nice Sophia Antipolis)

Keywords:Pocillopora meandrina, Porites lobata, Millepora platyphylla, morphometric analysis, Random Forest

Reef-building corals show high morphological variation within and among species. This variability can be associated with species plasticity and hybridization, phenotypic polymorphism, geographic distribution, and environmental factors hindering taxonomic identification. Recent studies have demonstrated the relevance of combining landmark skeleton morphometry and genetic analysis to identify coral species and the populations within. However, accurate and less destructive sampling methods are required for field studies. Therefore, robust and reproducible approaches are necessary for coral identification in the field. The Tara Pacific expedition collected more than 3000 coral samples from 32 different islands across two transects spanning the Pacific Ocean East-West and South-North. Three species, Pocillopora meandrina, Porites lobata and Millepora platyphylla were chosen based on their relative abundance and presence across the whole Pacific. Here, we tested whether it is possible to predict genetic lineages within these three genera from in situ photos. We used colony morphometric analysis and SNPs based genotyping combined with unsupervised and supervised machine learning random forest algorithm. We showed that only a limited number of genetic lineages could be predicted based on colony morphology with low error rates. Furthermore, discuss the potential effects of environmental factors such as temperature and wave intensity in determining the colony morphology. This study shows the potential and limitations of in situ photographs for the identification of genetic lineages in reef-building corals.