The genus Porites is one of the most important scleractinian genera in terms
of species diversity and panmictic tropical distribution. However, Porites is
notorious for challenging taxonomic identification based on colony gross
morphology, micromorphology, and single gene analyses, suggesting that
the current classification poorly represents real evolutionary relationships.
This research integrates skeletal morphology data and single locus
genetic evidence with genome-wide analyses and alternative line of
evidence to taxonomy (i.e. symbiotic association data), with the aim of
clarifying biodiversity, biogeography, and taxonomy of Porites from the
Arabian Peninsula.
In this dissertation, I evaluated the diversity of Porites in the Red Sea
and the Gulf of Aden, providing a basic morpho-molecular background to
the taxonomy of Porites in the region, and highlighting that a) the current
taxonomic and phylogenetic position of 15 Porites morphological species
needs to be reassessed, and that b) coral biodiversity in the Arabian region
needs to be re-evaluated. To address this, I reconstructed the complete
mitochondrial genomes of two endemic Red Sea species, contributing a
solid framework for clarifying the phylogeny and taxonomy of Porites in
future molecular studies. I implemented the morpho-molecular results with
high-throughput sequencing data, generating a comprehensive
hypothesis of species boundaries and biogeography of Porites in the seas
surrounding the Arabian Peninsula. These results suggested that 15
morphological species from this region, were clustered into eight molecular
lineages, two of which previously unknown. Finally, using the nuclear
Internal Transcribed Spacer II (ITS2) marker in a high-throughput sequencing
framework, I presented evidence derived from symbiotic association of
Porites with dinoflagellates in the family Symbiodiniaceae. Symbiont
diversity showed patterns of geographic-specific association at multiple
levels, including at the level of Symbiodiniaceae genera, majority ITS2
sequences, and ITS2 type profile levels. Specific associations with host
genotypes were also recovered, providing a further line of evidence that
the current taxonomy of Porites is in need for revision.
This dissertation highlights the utility of an integrated approach to
taxonomy in elucidating species boundaries and phylogenetic
relationships in Scleractinia and represents a framework that could be
applied to other taxa awaiting revision.
Date of Award | Dec 2019 |
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Original language | English (US) |
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Awarding Institution | - Biological, Environmental Sciences and Engineering
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Supervisor | Michael Berumen (Supervisor) |
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- Systematics
- Corals
- Species Delimitation
- Biodiversity,