PEET: Sea Cucumbers on Coral Reefs: Systematics of Aspidochirotid Holothurians

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AbstractCoral reefs harbor the greatest diversity of marine life and are the most vulnerable marine habitats to human disturbances. Even the order of magnitude of reef biodiversity is poorly known, yet eutrophication, overfishing, and global warming threaten the very existence of reef ecosystems. Documenting reef biodiversity is thus of the utmost urgency, so that baseline information becomes available about the diversity, distribution, and ecological roles of reef biota, against which future changes can be compared, and management and conservation decisions made. Sea cucumbers are among the most poorly known large marine invertebrates, especially on coral reefs. Yet sea cucumbers are among the most common and diverse large invertebrates on reefs, and a cornerstone of reef detrital food webs. Likely as many species remain undiscovered as have been described. Our knowledge of these striking, large animals lags behind that of many other groups partly because few scientists specialize on them and most that do are near or past retirement age. Large aspidochirotids, the focus of this proposal, are harvested in a multimillion-dollar beche-de-mer industry and sold as a gourmet food item in Asian markets. As Asian economies grow, demand for beche-de-mer is increasing and overfishing is a reality or an imminent threat in much of the tropics.The objective of this project is to greatly improve our understanding of sea cucumbers through large-scale, collaborative phylogenetic efforts, revisions, and training. Three graduate and several undergraduate students will be trained in modern systematics and pursue research on holothurians. PEET trainees, PIs will work with other holothurian specialists to collaboratively document a large portion of sea cucumber diversity. Three major groups preferentially targeted by fishers (Stichopodidae, Bohadschia and Actinopyga, comprising ca. 110 species) will be revised. A web site will be developed to include a comprehensive database of all aspidochirotids, including copies of all original descriptions and figures, updated synonymies and lassification, species pages, interactive keys, image libraries, GIS maps, and pdfs of the taxonomic literature on sea cucumbers. The group will develop a robust phylogeny of aspidochirotids using molecular and morphological approaches, and explore hypotheses about their evolution, ecology, biogeography, and biology. Phylogenies and revisions will be used to address questions about major biotic transitions (between tropical - temperate, shallow - deep, off reef - reef zones), patterns of marine speciation, and evolution of holothurian morphology and ecology. The phylogenetic approach will also help delineate species complexes and identify geographic limits of stocks. Having a taxonomic understanding of the biota is essential foundation for work on the ecology, conservation, and management of megadiversity ecosystems like coral reefs. Understanding the species-level taxonomy of sea cucumbers will facilitate efforts to manage fisheries, especially as several fished taxa are in unresolved species complexes, and stock limits are poorly understood. The abundant photographic and other documentation will foster attention and study of these animals by divers, naturalists, fisherman, and others.