17 research outputs found

    A novel widespread cryptic species and phylogeographic patterns within several giant clam species (Cardiidae: Tridacna) from the Indo-Pacific Ocean

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    Giant clams (genus Tridacna) are iconic coral reef animals of the Indian and Pacific Oceans, easily recognizable by their massive shells and vibrantly colored mantle tissue. Most Tridacna species are listed by CITES and the IUCN Redlist, as their populations have been extensively harvested and depleted in many regions. Here, we survey Tridacna crocea and Tridacna maxima from the eastern Indian and western Pacific Oceans for mitochondrial (COI and 16S) and nuclear (ITS) sequence variation and consolidate these data with previous published results using phylogenetic analyses. We find deep intraspecific differentiation within both T. crocea and T. maxima. In T. crocea we describe a previously undocumented phylogeographic division to the east of Cenderawasih Bay (northwest New Guinea), whereas for T. maxima the previously described, distinctive lineage of Cenderawasih Bay can be seen to also typify western Pacific populations. Furthermore, we find an undescribed, monophyletic group that is evolutionarily distinct from named Tridacna species at both mitochondrial and nuclear loci. This cryptic taxon is geographically widespread with a range extent that minimally includes much of the central Indo-Pacific region. Our results reinforce the emerging paradigm that cryptic species are common among marine invertebrates, even for conspicuous and culturally significant taxa. Additionally, our results add to identified locations of genetic differentiation across the central Indo-Pacific and highlight how phylogeographic patterns may differ even between closely related and co-distributed species

    Impact of Ocean Warming and Ocean Acidification on Larval Development and Calcification in the Sea Urchin Tripneustes gratilla

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    Background: As the oceans simultaneously warm, acidify and increase in P-CO2, prospects for marine biota are of concern. Calcifying species may find it difficult to produce their skeleton because ocean acidification decreases calcium carbonate saturation and accompanying hypercapnia suppresses metabolism. However, this may be buffered by enhanced growth and metabolism due to warming.Methodology/Principal Findings: We examined the interactive effects of near-future ocean warming and increased acidification/P-CO2 on larval development in the tropical sea urchin Tripneustes gratilla. Larvae were reared in multifactorial experiments in flow-through conditions in all combinations of three temperature and three pH/P-CO2 treatments. Experiments were placed in the setting of projected near future conditions for SE Australia, a global change hot spot. Increased acidity/P-CO2 and decreased carbonate mineral saturation significantly reduced larval growth resulting in decreased skeletal length. Increased temperature (+3 degrees C) stimulated growth, producing significantly bigger larvae across all pH/P-CO2 treatments up to a thermal threshold (+6 degrees C). Increased acidity (-0.3-0.5 pH units) and hypercapnia significantly reduced larval calcification. A +3 degrees C warming diminished the negative effects of acidification and hypercapnia on larval growth.Conclusions and Significance: This study of the effects of ocean warming and CO2 driven acidification on development and calcification of marine invertebrate larvae reared in experimental conditions from the outset of development (fertilization) shows the positive and negative effects of these stressors. In simultaneous exposure to stressors the dwarfing effects of acidification were dominant. Reduction in size of sea urchin larvae in a high P-CO2 ocean would likely impair their performance with negative consequent effects for benthic adult populations

    Comparative phylogeography of the Coral Triangle and implications for marine management

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    Extreme concentration of marine biodiversity and exploitation of marine resources in the Coral Triangle pose challenges to biogeographers and resource managers. Comparative phylogeography provides a powerful tool to test biogeographic hypotheses evoked to explain species richness in the Coral Triangle. It can also be used to delineate management units for marine resources. After about a decade of phylogeographical studies, patterns for the Coral Triangle are emerging. Broad connectivity in some species support the notion that larvae have maintained gene flow among distant populations for long periods. Other phylogeographic patterns suggest vicariant events resulting from Pleistocene sea level fluctuations, which have, at least occasionally, resulted in speciation. Divergence dates ranging back to the Miocene suggest that changing land configurations may have precipitated an explosion of species diversification. A synthesis of the marine phylogeographic studies reveals repeated patterns that corroborate hypothesized biogeographic processes and suggest improved management schemes for marine resources. © Copyright 2011 Kent E. Carpenter et al

    Advancing biodiversity research in developing countries: The need for changing paradigms

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    The world is in the midst of a biodiversity crisis, threatening essential goods and services on which humanity depends. While there is an urgent need globally for biodiversity research, growing obstacles are severely limiting biodiversity research throughout the developing world, particularly in Southeast Asia. Facilities, funding, and expertise are often limited throughout this region, reducing the capacity for local biodiversity research. Although western scientists generally have more expertise and capacity, international research has sometimes been exploitative parachute science, creating a culture of suspicion and mistrust. These issues, combined with misplaced fears of biopiracy, have resulted in severe roadblocks to biodiversity research in the very countries that need it the most. Here, we present an overview of challenges to biodiversity research and case studies that provide productive models for advancing biodiversity research in developing countries. Key to success is integration of research and education, a model that fosters sustained collaboration by focusing on the process of conducting biodiversity research as well as research results. This model simultaneously expands biodiversity research capacity while building trust across national borders. It is critical that developing countries enact policies that protect their biodiversity capital without shutting down international and local biodiversity research that is essential to achieve the long-term sustainability of biodiversity, promoting food security and economic development.© 2014 Rosenstiel School of Marine and Atmospheric Science of the University of Miami

    Lobster aquaculture development in Vietnam and Indonesia

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    Development of spiny (rock) lobster aquaculture is of special interest because market demand continues to increase while capture fisheries production remains static and with little likelihood of any increase. This chapter provides a synopsis of information about the history, development, status and future of tropical spiny lobster aquaculture with a particular focus on Vietnam and Indonesia, where considerable development has already occurred. Vietnam is the only country in the world where farming of lobsters is fully developed and commercially successful. The Vietnamese industry is based on a natural supply of seed lobsters – the puerulus stage, as hatchery supply is not yet available due to the difficult technical demands of rearing spiny lobster larvae in captivity. Vietnam currently produces around 1,600 tonnes of premium grade lobsters, primarily of the species Panulirus ornatus, that are exported to China where price is greatest. The industry is valued at over $US120 million. That success led to significant interest in Indonesia where a fishery for seed lobsters has become well developed, with a catch 10 to 20 times greater than that of Vietnam. However, growout of lobster in Indonesia remains insignificant due to adverse government policy and lack of farmer knowledge and skills. The seed lobsters available in Indonesia are primarily Panulirus homarus, a species with excellent production characteristics like P. ornatus, although with lesser value. Extraordinarily high abundance of naturally settling seed lobsters is apparent in selected areas due to a confluence of suitable conditions that create a high concentration of late stage larvae near the coast. These areas have been termed hotspots, as the availability of settling seed is much higher than other areas. Such hotspots are now recognized for the central northern coast of Vietnam – supplying their growout industry and the central southern coast of Indonesia. Natural mortality of the seed lobsters in these areas is correspondingly high due to insufficient settlement habitat and fish predation. Consequently, responsible fishing of these seed is sustainable, providing a valuable resource that can be on-grown for benefit of impoverished coastal communities. Innovative and inexpensive techniques have been developed to effectively catch the seed as they swim towards the coast seeking suitable habitat. In Vietnam, the seed are typically sold by fishers to dealers, who aggregate supplies and then on-sell to nursery farmers. Nursing consists of rearing the seed lobsters in small suspended or submerged cages, with a diet of fresh seafood – crabs, mollusc and fish. Advanced juvenile lobsters are produced that are in turn on-sold to growout farmers who stock them to larger floating cages, suspended from simple floating frames. The economics involve relatively low capital and operating costs, and production of high value product, that provides significant economic and social benefit to the communities involved. Although several health and disease issues have impacted spiny lobster farming, they can be effectively managed through good nutrition and husbandry. Market demand for spiny lobster from China is strong and growing, far exceeding supply. There appears to be great scope for much larger farm production of spiny lobsters with little impact on price. The future for tropical spiny lobster aquaculture appears to be very positive, particularly for developing countries in the Asian region, where seed are available, suitable growout locations are present and where costs of production are relatively low. It is expected that lobster aquaculture will continue to develop in the region, expanding beyond Vietnam and Indonesia
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