Taylor Ely1, Patrick Nichols1, Claire Lewis2, Peter Marko1, Cécile Vimond1
1University Of Hawai‘i At Mānoa, Honolulu, USA, 2Hawai‘i Institute of Marine Biology, Kane‘ohe, USA
Biography:
Cécile Vimond is a graduate student in the Zoology department at the University of Hawai‘i at Mānoa. Her research employs molecular techniques to explore ecological and evolutionary questions, with a focus on hidden diversity. Cécile’s use of eDNA metabarcoding aims to reveal cryptic coral diversity across the Hawaiian Islands, providing critical insights that can inform conservation and management strategies.
Abstract:
Knowledge of coral species diversity, community structure, and function has traditionally relied on morphological variation to differentiate species. Yet, coral morphology and its relationship to species boundaries are notoriously difficult to understand, leading to both under- and over-estimates of diversity. However, better molecular data have transformed our understanding of coral species boundaries. In the Agariciidae coral family, recent molecular studies have revealed numerous cryptic taxa within single widespread nominal species in the Indo-Pacific. This high diversity of morphologically-cryptic taxa, combined with the ecologically-cryptic nature of many agariciids, provides a unique opportunity to test an eDNA approach to assess diversity in taxa that are both difficult to visually identify and sample. We sequenced the mitochondrial cox1-1-rRNA spacer from water samples to evaluate agariciid diversity across four Main Hawaiian Islands. We detected 9 distinct clades of agariciids, including several cryptic lineages within the nominal Pavona varians. Our eDNA approach recovered more taxa than are known from visual surveys on shallow Hawaiian reefs. We also found significant differences in species richness and diversity across islands and sites. Environmental variation analysis revealed three key factors (rugosity, sedimentation, and temperature) shaping shallow agariciid community composition. Overall, this research demonstrates the power of eDNA to uncover hidden diversity and elucidate diversity patterns among agariciids in Hawai‘i.