The Experts below are selected from a list of 1092 Experts worldwide ranked by ideXlab platform
Michael M. Gangloff - One of the best experts on this subject based on the ideXlab platform.
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Molecular systematics of the critically-endangered North American spinymussels (Unionidae: Elliptio and Pleurobema) and description of Parvaspina gen. nov.
Conservation Genetics, 2017Co-Authors: Michael A. Perkins, Nathan A. Johnson, Michael M. GangloffAbstract:Despite being common in numerous marine bivalve lineages, lateral spines are extremely rare among freshwater bivalves (Bivalvia: Unionidae), with only three known species characterized by the presence of spines: Elliptio spinosa, Elliptio steinstansana , and Pleurobema collina . All three taxa are endemic to the Atlantic Slope of southeastern North America, critically endangered, and protected by the US Endangered Species Act. Currently, these species are recognized in two genera and remain a source of considerable taxonomic confusion. Because spines are rare in freshwater mussels and restricted to a small region of North America, we hypothesized that spinymussels represent a monophyletic group. We sequenced two mtDNA gene fragments ( COI and ND1 ) and a fragment of the nuclear ITS-1 locus from >70 specimens. Bayesian and maximum-likelihood phylogenetic reconstructions suggest that the spinymussels do not comprise a monophyletic group. Elliptio steinstansana is sister to P. collina , forming a monophyletic clade that was estimated to have diverged from its most recent ancestor in the late Miocene and is distinct from both Elliptio and Pleurobema ; we describe a new genus ( Parvaspina gen. nov.) to reflect this relationship. Additionally, E. spinosa forms a monophyletic clade that diverged from members of the core Elliptio lineage in the mid-Pliocene. Furthermore, E. spinosa is genetically divergent from the other spinymussel species, suggesting that spines, while extremely rare in freshwater mussels worldwide, may have evolved independently in two bivalve lineages. Recognizing the genetic distinctiveness and inter-generic relationships of the spinymussels is an important first step towards effectively managing these imperiled species and lays the groundwork for future conservation genetics studies.
Michael A. Perkins - One of the best experts on this subject based on the ideXlab platform.
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Molecular systematics of the critically-endangered North American spinymussels (Unionidae: Elliptio and Pleurobema) and description of Parvaspina gen. nov.
Conservation Genetics, 2017Co-Authors: Michael A. Perkins, Nathan A. Johnson, Michael M. GangloffAbstract:Despite being common in numerous marine bivalve lineages, lateral spines are extremely rare among freshwater bivalves (Bivalvia: Unionidae), with only three known species characterized by the presence of spines: Elliptio spinosa, Elliptio steinstansana , and Pleurobema collina . All three taxa are endemic to the Atlantic Slope of southeastern North America, critically endangered, and protected by the US Endangered Species Act. Currently, these species are recognized in two genera and remain a source of considerable taxonomic confusion. Because spines are rare in freshwater mussels and restricted to a small region of North America, we hypothesized that spinymussels represent a monophyletic group. We sequenced two mtDNA gene fragments ( COI and ND1 ) and a fragment of the nuclear ITS-1 locus from >70 specimens. Bayesian and maximum-likelihood phylogenetic reconstructions suggest that the spinymussels do not comprise a monophyletic group. Elliptio steinstansana is sister to P. collina , forming a monophyletic clade that was estimated to have diverged from its most recent ancestor in the late Miocene and is distinct from both Elliptio and Pleurobema ; we describe a new genus ( Parvaspina gen. nov.) to reflect this relationship. Additionally, E. spinosa forms a monophyletic clade that diverged from members of the core Elliptio lineage in the mid-Pliocene. Furthermore, E. spinosa is genetically divergent from the other spinymussel species, suggesting that spines, while extremely rare in freshwater mussels worldwide, may have evolved independently in two bivalve lineages. Recognizing the genetic distinctiveness and inter-generic relationships of the spinymussels is an important first step towards effectively managing these imperiled species and lays the groundwork for future conservation genetics studies.
Nathan A. Johnson - One of the best experts on this subject based on the ideXlab platform.
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Molecular systematics of the critically-endangered North American spinymussels (Unionidae: Elliptio and Pleurobema) and description of Parvaspina gen. nov.
Conservation Genetics, 2017Co-Authors: Michael A. Perkins, Nathan A. Johnson, Michael M. GangloffAbstract:Despite being common in numerous marine bivalve lineages, lateral spines are extremely rare among freshwater bivalves (Bivalvia: Unionidae), with only three known species characterized by the presence of spines: Elliptio spinosa, Elliptio steinstansana , and Pleurobema collina . All three taxa are endemic to the Atlantic Slope of southeastern North America, critically endangered, and protected by the US Endangered Species Act. Currently, these species are recognized in two genera and remain a source of considerable taxonomic confusion. Because spines are rare in freshwater mussels and restricted to a small region of North America, we hypothesized that spinymussels represent a monophyletic group. We sequenced two mtDNA gene fragments ( COI and ND1 ) and a fragment of the nuclear ITS-1 locus from >70 specimens. Bayesian and maximum-likelihood phylogenetic reconstructions suggest that the spinymussels do not comprise a monophyletic group. Elliptio steinstansana is sister to P. collina , forming a monophyletic clade that was estimated to have diverged from its most recent ancestor in the late Miocene and is distinct from both Elliptio and Pleurobema ; we describe a new genus ( Parvaspina gen. nov.) to reflect this relationship. Additionally, E. spinosa forms a monophyletic clade that diverged from members of the core Elliptio lineage in the mid-Pliocene. Furthermore, E. spinosa is genetically divergent from the other spinymussel species, suggesting that spines, while extremely rare in freshwater mussels worldwide, may have evolved independently in two bivalve lineages. Recognizing the genetic distinctiveness and inter-generic relationships of the spinymussels is an important first step towards effectively managing these imperiled species and lays the groundwork for future conservation genetics studies.
Michael Perkins - One of the best experts on this subject based on the ideXlab platform.
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Phylogeny of the critically endangered North American spinymussels (Unionidae: Elliptio and Pleurobema)
2015Co-Authors: Michael PerkinsAbstract:Lateral spines are uncommon among freshwater bivalves. The North American freshwater mussel fauna includes three taxa that exhibit spines: Elliptio spinosa, Elliptio steinstansana, and Pleurobema collina. All three taxa are endemic to the Southeastern US, and critically endangered. Currently, these species are recognized in two genera and are a source of taxonomic confusion within the unionid tribe Pleurobemini (Elliptio and Pleurobema). Because freshwater mussels exhibit phenotypically plastic shell morphology, morphologically-based diagnoses are problematic. I sequenced two mtDNA gene fragments and a fragment of the nuclear ITS-1 locus from >70 spinymussel specimens. Bayesian phylogenetic reconstructions suggest that the spinymussels do not comprise a monophyletic group. Elliptio steinstansana is sister to P. collina and these taxa form a monophyletic clade that possibly diverged from its nearest ancestor in the late Miocene. Additionally, E. spinosa forms a monophyletic clade that diverged from members of the core Elliptio lineage in the mid Pliocene, >1.5 million years before multiple radiations within the Elliptio clade. Furthermore, E. spinosa is divergent from the other spinymussels, suggesting that spines have evolved separately in two distinct bivalve lineages endemic to this region. These findings suggest a need to revise the taxonomy of this highly imperiled mussel group.
Paul H. Lord - One of the best experts on this subject based on the ideXlab platform.
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Reproductive Phenology of Elliptio complanata in an Upper Susquehanna River Tributary of New York
Northeastern Naturalist, 2019Co-Authors: Thomas P. Franzem, Mark L. Kugler, Paul H. Lord, Robin Larochelle, Daniel S. Stich, Andrew Gascho LandisAbstract:Elliptio complanata (Eastern Elliptio) is typically an abundant species in lotic systems throughout the northeastern US; however, as with many other freshwater mussel species, some populations of Eastern Elliptio are in decline. Freshwater mussels have complex life cycles, which are important to understand for their conservation and management. The goal of this study was to determine the timing of Eastern Elliptio spawning, brooding, and glochidia release. Throughout the spawning season, we used gonad and gill extracts and drift nets to track the timing of reproduction in Otego Creek, NY, a tributary to the Susquehanna River. Females began brooding fertilized eggs by mid-May, and by early June, all females collected were brooding fertilized eggs or d-shaped glochidia. The temperature was 18 °C when all females contained glochidia. Peak glochidia-drift occurred ∼1 week after we recorded the highest levels of brooding and continued at low levels for several weeks. Phenology modeling helped us to determine that accumulated thermal units was the best predictor of reproductive activity. Our work highlights the environmental cues responsible for spawning, brooding, and glochidia release in a population of Eastern Elliptio. This empirical approach to predicting reproductive activity has great potential as a tool for timing the collection of brood stock for propagation or other important conservation measures.
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Populations on the brink: predictive estimates of time since recruitment for Elliptio complanata by thin-section aging of deceased individuals
2017Co-Authors: Mark L. Kugler, A.m. Gascho Landis, Paul H. LordAbstract:The population of Eastern Elliptio (Elliptio complanata) in the Susquehanna Watershed consists of older individuals that are not successfully reproducing. Recruitment failure often occurs before adult mortality, which can result in relict populations that persist for decades (Strayer & Malcolm, 2012).