Megan Osborne

Megan Osborne
University of New Mexico | UNM · Department of Biology

PhD, La Trobe University

About

114
Publications
8,018
Reads
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765
Citations
Citations since 2017
19 Research Items
380 Citations
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Additional affiliations
January 2006 - present
University of New Mexico
Description
  • I conduct research that employs a comparative approach to evaluate intrinsic and extrinsic factors to understand the causes and consequences of metapopulation connectivity for maintenance of biodiversity and genetic integrity of species.
Education
March 1997 - March 2002
La Trobe University
Field of study
  • Systematics, phylogenetics of diprotodontid marsupials
March 1991 - November 1995
La Trobe University
Field of study
  • Genetics and Zoology

Publications

Publications (114)
Article
Full-text available
Studying the reproductive ecology of aggregate broadcast spawning fishes is difficult because it generally is not feasible to sample all potential parents and unambiguously assign their offspring. We used molecular‐based parentage analysis to gain insights into the reproductive ecology of the endangered Bonytail, and to evaluate whether protected o...
Article
Hatchery programs are critical for conservation and management of many imperiled fishes. Most traditional aquaculture programs negatively affect ecological performance, genetic, and phenotypic diversity of hatchery-origin fish compared with wild counterparts. Here, we synthesize outcomes of three conservation programs aimed at enhancing ‘wildness’....
Article
Full-text available
The Rio Grande drainage of the southwestern United States and Mexico has undergone intense anthropogenic alteration by water diversions, extraction and associated habitat changes. These alterations have disproportionately impacted the pelagic broadcast spawning guild of minnows (pelagophils). Several Rio Grande endemic pelagophils, including the co...
Article
Full-text available
Pelagic broadcast spawning cyprinids have declined throughout the North American Great Plains because of adverse habitat changes caused by river fragmentation and altered flow regimes. Despite losses elsewhere, a 218-river kilometer section of the South Canadian River maintains three of these imperiled species: Arkansas River Shiner, Peppered Chub...
Article
Full-text available
Many long-term genetic monitoring programs began before next-generation sequencing became widely available. Older programs can now transition to new marker systems usually consisting of 1000s of SNP loci, but there are still important questions about comparability, precision, and accuracy of key metrics estimated using SNPs. Ideally, transitioned p...
Preprint
Full-text available
Many long-term genetic monitoring programs began before next-generation sequencing became widely available. Older programs can now transition to new marker systems usually consisting of 1000s of SNP loci, but there are still important questions about comparability, precision, and accuracy of key metrics estimated using SNPs. Ideally, transitioned p...
Presentation
Full-text available
Sex determination systems and genetic sex differentiation across fishes are highly diverse and can be complex. A variety of sex determination systems have been described within the order Cypriniformes, but for most species, it remains unknown. One such species is Rio Grande silvery minnow (Hybognathus amarus) that like many cypriniform fishes is go...
Preprint
Sex determination systems and genetic sex differentiation across fishes are highly diverse but are unknown for most Cypriniformes, including Rio Grande silvery minnow (Hybognathus amarus). In this study, we aimed to detect and validate sex-linked markers to infer sex determination system and to demonstrate the utility of combining several methods f...
Article
Full-text available
Many salmonids exist in highly structured and isolated populations, and are susceptible to habitat fragmentation and disturbances. Gila Trout (Oncorhynhus gilae) is a threatened species found in the Southwestern United States, and is managed to preserve relict populations (i.e., lineages) distributed across a fragmented landscape. We evaluated geno...
Article
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Cyprinodon is renowned for localized endemism across the North American desert. Competing molecular studies have made elucidating timing of diversification across the desert controversial. Debate has focused on Mojave Desert species, with limited evaluation of other evidence. However, the Great Plains and Chihuahuan Desert harbor more taxonomic div...
Chapter
Full-text available
At its core, conservation genetics aims to characterize genetic diversity in space and time, to infer processes that change diversity, and to use that information to prescribe actions that maintain and enhance diversity and self-sustainability of imperiled species. The field of conservation genomics, fueled by rapid advances in DNA sequencing and g...
Article
Full-text available
Rio Grande Sucker is continuously distributed in parts of its range, but occurs in geographically isolated populations at the periphery. We used ten microsatellites and DNA sequence data from the mitochondrial cytochrome-b gene to characterize genetic diversity and reconstruct evolutionary relationships of five peripheral populations in the southwe...
Article
Full-text available
Gila elegans, Hybognathus amarus, and Tiaroga cobitis (Family Cyprinidae, Order Cypriniformes) are endemic and endangered fishes in the southwestern United States. We present complete mitochondrial genomes for each species. Each mitochondrion consisted of 13 protein-coding genes, 2 ribosomal (rRNA) genes, 22 transfer RNA (tRNA) genes, and a single...
Article
Simultaneous management actions often are used to improve the status of imperiled species yet the effects of these actions can be difficult to determine. The endangered Rio Grande Silvery Minnow is a short‐lived fish with a dispersive life history and thus requires‐ but does not occupy‐ unfragmented habitat for recruitment and survival. We used Rio...
Article
We report results from a 3-year field investigation to limit hybridization between native and nonnative suckers in 2 small tributaries of the Gunnison River basin, Delta County, Colorado. Upstream movement to spawning habitat was selectively impeded by picket weir in intermittent Cottonwood Creek. There, native suckers were identified based on morp...
Preprint
Full-text available
In the late 1940s, Rio Grande Sucker Pantosteus plebeius was reported in tributaries of the Gila River in the Colorado Basin and presumed to be introduced because of its absence in mid-19th century surveys. We assayed genetic variation at 10 microsatellite loci and two mtDNA genes (cyt b and ND4) to test the hypothesis of human-mediated introductio...
Article
Full-text available
The Sacramento Mountain Salamander (Aneides hardii) is a fully terrestrial plethodontid endemic to mountains in south-central New Mexico. Aneides hardii is a species of conservation concern in New Mexico but there is scant knowledge regarding the degree of genetic divergence among populations. This information is vital for developing an appropriate...
Article
Full-text available
Climate change will strongly impact aquatic ecosystems particularly in arid and semi-arid regions. Fish-parasite interactions will also be affected by predicted altered flow and temperature regimes, and other environmental stressors. Hence, identifying environmental and genetic factors associated with maintaining diversity at immune genes is critic...
Article
Full-text available
A local hybrid swarm between Etheostoma radiosum and Etheostoma spectabile, found in June 1985 in a short reach of Little Glasses Creek, southern Oklahoma, consisted by eye of 35% phenotypic E. radiosum, 18% phenotypic E. spectabile, and 47% hybrids. In July 1985, investigation of an additional longer reach downstream of the initial discovery site...
Article
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Thorough sampling is necessary to delineate lineage diversity for polytypic ‘species’ such as Cyprinella lutrensis. We conducted extensive mtDNA sampling (cytochrome b and ND4) from the Pecos River, Rio Grande, and South Canadian River, New Mexico. Our study focussed on the Pecos River due to its complex geological history and potential to harbour...
Article
We used comparative landscape genetics to examine the relative roles of historical events, intrinsic traits, and landscape factors in determining the distribution of genetic diversity of river fishes across the North American Great Plains. Spatial patterns of diversity were overlaid on a patch-based graphical model, and then compared within and amo...
Article
Full-text available
In desert streams, fishes and other organisms that depend on surface water are predicted to inhabit smaller and more isolated wetted reaches, while the frequency and severity of disturbance is expected to increase under most climate change models. Together, these factors should reduce population genetic diversity and persistence probabilities. In t...
Article
Biodiversity in stream networks is threatened globally by interactions between habitat fragmentation and altered hydrologic regimes. In the Great Plains of North America, stream networks are fragmented by >19,000 anthropogenic barriers and flow regimes are altered by surface water retention and groundwater extraction. We documented the distribution...
Article
Full-text available
The Arkansas River Shiner is a threatened species that has been extirpated throughout much of its native range (Arkansas River drainage) and remaining populations are imperiled. Prior to 1978, this species was accidently introduced to the Pecos River (Rio Grande drainage) via bait bucket, and has since persisted for over 30 years. Genetic data show...
Article
Full-text available
Captive breeding and rearing are central elements in conservation, management, and recovery planning for many endangered species including Rio Grande Silvery Minnow, a North American freshwater cyprinid. Traditionally, the sole purpose of hatcheries was to produce as many fish as feasible for stocking and harvest. Production quotas are also an impo...
Technical Report
Full-text available
It is widely known that the health of fish can be adversely affected by exposure to water pollution. In 2005, the Middle Rio Grande Endangered Species Act Collaborative Program (Collaborative Program) requested proposals for monitoring the health conditions of Rio Grande silvery minnow (Hybognathus amarus; RGSM) in the mainstem of the Middle Rio Gr...
Article
Full-text available
Genetic drift is expected to be the predominant evolutionary force in small, fragmented peripheral populations, which can lead to divergent allele frequencies and lowered diversity compared to the core population. Peripheral populations are not considered a high priority for conservation for this reason. However, peripheral populations may possess...
Article
Full-text available
The endangered Rio Grande silvery minnow persists as a remnant population in a highly fragmented and regulated arid‐land river system. The species is subject to dramatic annual fluctuations in density. Since 2003, the wild population has been supplemented by hatchery‐reared fish. We report on a 12‐year (1999–2010) monitoring study of genetic divers...
Article
Full-text available
Genetic monitoring tracks changes in measures of diversity including allelic richness, heterozygosity and genetic effective size over time, and has emerged as an important tool for understanding evolutionary consequences of population management. One proposed application of genetic monitoring has been to estimate abundance and its trajectory throug...
Article
Full-text available
We developed 10 polymorphic microsatellite markers for the federally endangered razorback sucker, Xyrauchen texanus. PCR optimization and cross-species amplification experiments indicated that these markers will be useful for analysis of fine-scale population structure in razorback and two other sucker species; the white sucker, Catostomus commerso...
Article
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The Pecos bluntnose shiner recovery plan (U.S. Fish & Wildlife Service 1992) includes reintroductions of the species into suitable habitat within its historic range and the development of a broodstock and/or refugial population. Furthermore, it states that the broodstock / refugial population size and spawning methods should seek to minimize the lo...
Article
Full-text available
We used 991 bp of mtDNA (D-loop/ND4L/ND4) and eight microsatellite loci to examine population structure and genetic diversity of Catostomus plebeius from nine localities across the northern part of its range in New Mexico. Two phylogeographic regions (Mimbres and Rio Grande) were defined by phylogenetically distinct collections of mtDNA haplotypes....
Article
Full-text available
Successful recovery and sustainability of threatened and exploited species depends in part on retention and maintenance of genetic diversity. Theory indicates that genetic diversity is lost at a rate inversely proportional to the genetically effective population size (N(e)), which is roughly equal to one-half the adult census size (N) in many organ...
Article
Full-text available
The Rio Grande silvery minnow, Hybognathus amarus , is a federally endangered cyprinid now confined to the middle Rio Grande, New Mexico, in a fraction of its former range. The precipitous decline of the remaining wild population and lack of recruitment in the summer of 2000 prompted collection and placement of eggs and wild fish in propagation fac...
Article
Full-text available
A sweepstakes–mismatch process whereby reproduction is poorly coordinated with appropriate resources for larval development and recruitment can result in large variance in reproductive success among individuals and spawning aggregations. This process has been proposed to explain low ratio of genetic effective population size (Ne) to adult census si...
Article
Full-text available
Museum records indicate that Hybognathus placitus was introduced into the Pecos River, New Mexico during the early 1960s. Approximately 10 years later, a congener, Hybognathus amarus, was extirpated from the system. We used microsatellite and mtDNA data, ecological data and modelling, and a computer simulation approach to reconstruct the history of...
Article
Full-text available
Mitochondrial ND2 sequences were used to investigate the phylogenetic relationships amongst 31 diprotodontid marsupials (kangaroos, wombats, koala, possums, and allies). ND2 sequences were analyzed separately and in conjunction with available 12S rDNA sequences for 22 diprotodontid taxa. Phylogenetic analyses consistently identified monophyly for t...