757 research outputs found

    HS 159B: Health Promotion Program Planning for Community Change Textbook Alternatives

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    Poster summarizing cost saving textbook alternatives for HS 159B: Health Promotion Program Planning for Community Change.https://scholarworks.sjsu.edu/davinci_tap2014/1006/thumbnail.jp

    Perspectives on the Controlled Propagation, Augmentation, and Reintroduction of Freshwater Mussels (Mollusca: Bivalvia: Unionoida)

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    Controlled propagation, augmentation, and reintroduction (PAR) of rare and endangered aquatic organisms has become a priority action for recovery and delisting, and in many cases is an action of ‘‘last resort’’ to either restore or maintain existing populations. The guiding principle of PAR efforts should be to avoid harming existing populations of congeneric or nontarget species and also minimize risks to extant populations and habitats. Controlled PAR of freshwater mussels should not be a long-term management strategy conducted in perpetuity and should not be used as a substitute for recovery tasks such as habitat restoration or addressing the causes of endangerment. The determination to pursue controlled PAR for freshwater mussels should follow a thorough evaluation of the status of existing wild populations, an agreement that PAR in the historic range is needed, and a conclusion that suitable habitat for long-term success is present. The primary purpose of any efforts to augment or reintroduce animals should be to establish free-ranging wild populations. Concomitant with this goal is the distinct possibility that these activities can represent appreciable genetic or ecological risks to resident animals, both nontarget taxa and wild conspecifics. To maintain the integrity of the fauna, communities, and ecosystems it is imperative that these risks be carefully considered before conducting controlled PAR. In this paper we pose several questions that we believe are important to consider before initiating PAR of freshwater mussels. We also recommend actions, some already used at individual facilities or by agencies, that we believe will aid in developing a more uniform approach to controlled PAR and safeguarding the ecological and genetic integrity of freshwater mussel communities

    A comparison of genetic diversity and population structure of the endangered scaleshell mussel (Leptodea leptodon), the fragile papershell (Leptodea fragilis) and their host-fish the freshwater drum (Aplodinotus grunniens)

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    The larvae of freshwater mussels in the order Unionoida are obligate parasites on fishes. Because adult mussels are infaunal and largely sessile, it is generally assumed that the majority of gene flow among mussel populations relies on the dispersal of larvae by their hosts. The objective of this study was to compare the genetic diversity and the degree of congruence between the population structures of two related freshwater mussels Leptodea leptodon and Leptodea fragilis and their fish host, Aplodinotus grunniens. Host specificity in parasites has been shown to result in greater congruence between the population structures of the two interacting species, and assessing the congruence of genetic structure of the endangered L. leptodon with its sister species L. fragilis and their sole host is an important step in understanding the impact of host dispersal on population structure. Analysis of microsatellite data indicated that despite its imperiled status, L. leptodon displayed greater genetic diversity than the more common L. fragilis. However, the population structures of all three species were incongruent even in the presence of substantial gene flow. Other factors such as habitat specificity may play a role in generating the differences in population structure observed. This study indicates that barriers to gene flow or lack of available host fish are not the cause of decline of the federally endangered L. leptodon, and suggests that alternative explanations should be considered

    Incongruence between mtDNA and nuclear data in the freshwater mussel genus Cyprogenia (Bivalvia: Unionidae) and its impact on species delineation

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    Accurately identifying species is a crucial step for developing conservation strategies for freshwater mussels, one of the most imperiled faunas in North America. This study uses genetic data to re-examine species delineation in the genus Cyprogenia. Historically, Cyprogenia found west of the Mississippi River have been ascribed to Cyprogenia aberti (Conrad 1850), and those east of the Mississippi River were classified as Cyprogenia stegaria (Rafinesque 1820). Previous studies using mitochondrial DNA sequences indicated that C. aberti and C. stegaria were not reciprocally monophyletic groups, suggesting the need for systematic revision. We generated a novel dataset consisting of 10 microsatellite loci and combined it with sequence data from the mitochondrial ND1 gene for 223 Cyprogenia specimens. Bayesian analysis of the ND1 nucleotide sequences identified two divergent clades that differ by 15.9%. Members of these two clades occur sympatrically across most sampling locations. In contrast, microsatellite genotypes support recognition of three allopatric clusters defined by major hydrologic basins. The divergent mitochondrial lineages are highly correlated with the color of the conglutinate lures used by mussels to attract and infest host fishes, and tests for selection at the ND1 locus were positive. We infer that the incongruence between mtDNA and microsatellite data in Cyprogenia may be the result of a combination of incomplete lineage sorting and balancing selection on lure color. Our results provide further evidence that mitochondrial markers are not always neutral with respect to selection, and highlight the potential problems of relying on a single-locus-marker for delineating species

    Genetic Analysis of the Federally Endangered Winged Mapleleaf Mussel to Aid Proposed Re-introduction Efforts

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    The winged mapleleaf, Quadrula fragosa, historically occurred in the Mississippi, Tennessee, Ohio, and Cumberland river drainages, but has suffered severe population and range reductions. At the time that the species was federally listed as endangered, its range was thought to have been reduced to a stretch of the St. Croix River between northwestern Wisconsin and east-central Minnesota. Recently, morphologically “Q. fragosa-like” specimens were discovered at sites in Arkansas (Ouachita River and Saline River), Missouri (Bourbeuse River), and Oklahoma (Little River). Subsequently, a plan was proposed to re-introduce Q. fragosa into portions of its historic range where its been extirpated from within the upper Mississippi River basin. The project objectives were 1.) Recommend the number of “founder” individuals required to generate the same level of genetic diversity in a newly established population as seen in the original population; 2.) In addition, allow for the ability to identify newly recruited juvenile mussels using microsatellite genotyping, and link individuals from the founded population back to the St. Croix River source population

    Boone River Watershed Stream Fish and Habitat Monitoring, IA

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    Historically, Iowa’s landscape consisted of prairies, forests, and wetlands with meandering streams integrated throughout (Hewes 1950). The arrival and subsequent settlement of European immigrants began a long process of altering the landscape to help meet human needs. Cultivating row crops in Iowa became a popular and successful venture for many as the flat, fertile ground of the Midwestern United States provided a great opportunity for farmers (Easterlin 1976). Early Iowa farmers began to drain wetlands, cut down forests, remove prairies, and replace them with crop fields (Gallant et al. 2011). As the technology of farming practices improved and operations became larger, streams were altered to aid in irrigation, removal of excess water from fields, and flood control (Iowa Department of Natural Resources 2015b). Portions of streams that once meandered through the forest were straightened and redirected between crop fields. Across Iowa, fast moving riffles and slow pools were replaced by stretches of run habitat (Iowa Department of Natural Resources 2015b). These habitat alterations negatively impacted many fish species (Hughes et al. 1990; Gallant et al. 2011)

    Freshwater bivalve (Unioniformes) diversity, systematics, and evolution: status and future directions

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    Freshwater bivalves of the order Unioniformes represent the largest bivalve radiation in freshwater. The unioniform radiation is unique in the class Bivalvia because it has an obligate parasitic larval stage on the gills or fins of fish; it is divided into 6 families, 181 genera, and ∼800 species. These families are distributed across 6 of the 7 continents and represent the most endangered group of freshwater animals alive today. North American unioniform bivalves have been the subject of study and illustration since Martin Lister, 1686, and over the past 320 y, significant gains have been made in our understanding of the evolutionary history and systematics of these animals. Here, the current state of unioniform systematics and evolution is summarized, and suggestions for future research themes are proposed. Advancement in the areas of systematics and evolutionary relationships within the Unioniformes will require a resurgence of survey work and reevaluation of all taxa, especially outside of North America and Western Europe. This work will require collection of animals for shell morphology, comparative anatomy, and molecular analyses. Along with reexamination of described taxa, a renewed emphasis on the natural history, host-fish relationships, ecology, and physiology of these animals is needed. Traditional conchological and anatomical characters should be reevaluated, new character suites should be added, and new morphometric methods should be applied. The fossil record of freshwater bivalves should be carefully reviewed, and phylogenetic hypotheses including fossil taxa must be developed. We will have to expand our set of molecular tools to include or develop additional markers, such as single-copy nuclear genes and microsatellites. Examination of double uniparental inheritance of mitochondrial deoxyribonucleic acid (DNA) is providing new insights into the evolution of this order. Mitochondrial gene order differs among genera but is still to be explored. Expansion of our understanding of the evolutionary relationships and history of unioniform bivalves will provide a solid foundation to study the zoogeography of these rather sessile, obligate freshwater organisms. The unique natural history of unioniform bivalves provides a fertile area for testing and developing evolutionary theories, and, as our understanding of the systematics of these animals improves, a better understanding of the evolution of this expansive radiation in freshwater will develop.This article is from Journal of the North American Benthological Society 27 (2008): 349, doi:10.1899/07-069.1. Posted with permission.</p

    Status of the Topeka Shiner in Iowa

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    The Topeka shiner Notropis topeka is native to Iowa, Kansas, Minnesota, Missouri, Nebraska, and South Dakota and has been federally listed as endangered since 1998. Our goals were to determine the present distribution and qualitative status of Topeka shiners throughout its current range in Iowa and characterize the extent of decline in relation to its historic distribution. We compared the current (2016–2017) distribution to distributions portrayed in three earlier time periods. In 2016–2017 Topeka shiners were found in 12 of 20 HUC10 watersheds where they occurred historically. Their status was classified as stable in 21% of the HUC10 watersheds, possibly stable in 25%, possibly recovering in 8%, at risk in 33%, and possibly extirpated in 13% of the watersheds. The increasing trend in percent decline evident in earlier time periods reversed, going from 68% in 2010–11 to 40% in the most recent surveys. Following decades of decline, the status of Topeka shiners in Iowa appears to be improving. One potential reason for the reversal in the distributional decline of Topeka shiners in Iowa is the increasing number of oxbow restorations. Until a standardized monitoring program is established for Iowa, periodic status assessments such as this will be necessary to chronicle progress toward conserving this endangered fish species

    Notes and Discussion Piece: Status of the Topeka Shiner in Iowa

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    The Topeka shiner Notropis topeka is native to Iowa, Kansas, Minnesota, Missouri, Nebraska, and South Dakota and has been federally listed as endangered since 1998. Our goals were to determine the present distribution and qualitative status of Topeka shiners throughout its current range in Iowa and characterize the extent of decline in relation to its historic distribution. We compared the current (2016–2017) distribution to distributions portrayed in three earlier time periods. In 2016–2017 Topeka shiners were found in 12 of 20 HUC10 watersheds where they occurred historically. Their status was classified as stable in 21% of the HUC10 watersheds, possibly stable in 25%, possibly recovering in 8%, at risk in 33%, and possibly extirpated in 13% of the watersheds. The increasing trend in percent decline evident in earlier time periods reversed, going from 68% in 2010–11 to 40% in the most recent surveys. Following decades of decline, the status of Topeka shiners in Iowa appears to be improving. One potential reason for the reversal in the distributional decline of Topeka shiners in Iowa is the increasing number of oxbow restorations. Until a standardized monitoring program is established for Iowa, periodic status assessments such as this will be necessary to chronicle progress toward conserving this endangered fish species
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