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Documentation of biodiversity and its geographical distribution is necessary to understand the processes and drivers of evolutionary diversification as well as to guide conservation and management initiatives. Among the most emblematic patterns of biodiversity in the world’s oceans is the Coral Triangle (Indo-Australian Archipelago), widely recognized to be the center of species richness for a variety of marine life forms. The distribution of biodiversity remains incompletely documented, however, for a majority of reef-associated invertebrate taxa, including the zooxanthellate soft corals (Octocorallia) that dominate hard substrate on many Indo-Pacific reefs. We used a genetic approach to document the diversity of Indo-Pacific soft corals, sequencing two single-locus barcoding markers for > 4400 soft coral specimens and assigning individuals to molecular operational taxonomic units as proxies of species. We document two centers of species richness for zooxanthellate soft corals, one in the Indo-Australian Archipelago and a second, equally diverse center in the Western Indian Ocean. Centers of endemicity for soft corals are coincident with these centers of species richness, although the peripheral Red Sea and Hawaii also support high proportions of endemic taxa. The patterns documented here suggest that biogeographic distributions of soft coral families may be driven in part by larval dispersal potential: taxa with benthic larvae are absent from most oceanic islands of the central Pacific and are represented by higher proportions of endemic taxa in other geographic regions. Our findings demonstrate the distinct biogeographic patterns among reef taxa and underscore the need to document and analyze species distributions of more reef-associated invertebrate groups to derive a complete picture of reef biogeography.
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Diversity squared: New insights into patterns of heterobranch species richness and diversification of lineages
Expeditionary field work still remains the most fundamental tool to discover novel species and repetitive sampling in high diversity portions of the Indo-Pacific tropics continues to provide large numbers of previously undocumented taxa. Multidisciplinary collaborative teams and large expeditions are an immense source of novel biodiversity. Micro-scale temporal changes in diverse ecosystems provide a catalyst for new species discovery, as well as insights into the discovery of patterns of trophic and symbiotic divergence. Additionally, phylogenetic analyses of large samples of diverse taxa across geographical gradients have increasingly detected cryptic and pseudo-cryptic species complexes that have dramatically altered our view of species richness. Aposematic and extreme camouflaged colour patterns within the context of fish predatory behaviour provides an evolutionary framework for divergence and convergence of colour patterns. Similarly, recent studies of temperate nudibranch assemblages in temperate waters in Europe, southern Africa and the Pacific coast of North America also demonstrate previously undetected diversity and the presence of colour patterns that likely reflect similarity derived from both common ancestry and convergence. Combining these approaches has documented astonishingly high levels of previously undetected diversity, has huge implications to our knowledge of global biodiversity with a likely 3-5x increase in global species richness, and has developed more appropriate regenerative conservation strategies.
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- Award ID(s):
- 1856407
- PAR ID:
- 10349314
- Date Published:
- Journal Name:
- Spixiana Supplement
- Volume:
- 30A
- ISSN:
- 0177-7424
- Page Range / eLocation ID:
- 33
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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