VTechWorks Repository :: Browsing by Author "Jones, Jess W."

Browsing by Author "Jones, Jess W."

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Assessment of morphological and molecular genetic variation of freshwater mussel species belonging to the genera Fusconaia, Pleurobema, and Pleuronaia in the upper Tennessee River basin
Schilling, Daniel Edward (Virginia Tech, 2015-07-07)
Select freshwater mussels in the genera Fusconaia, Pleurobema, and Pleuronaia were collected primarily in the upper Tennessee River basin from 2012 to 2014 for phylogenetic and morphological assessments. Freshwater mussels in these genera are similar in appearance, hence the need for phylogenetic verification and morphological assessment. Phylogenetic analyses of the mitochondrial gene ND1 and the nuclear gene ITS1 revealed three unrecognized, phylogenetically distinct species. These species were separated from their closest congener by 2.85%, 3.17%, and 6.32% based on pairwise genetic distances of ND1. Gaps created from aligning ITS1 sequences were coded as fifth characters, which phylogenetically separated most closely related species. Analyses of ND1 agreed with previous literature on the phylogenetic distinctiveness of Pleuronaia species, with the exception of the DNA sequences of P. gibberum, which grouped outside this genus based on the analyses conducted in this study. Morphological variation was recorded for eight of the species to include quantitative and qualitative characters as well as geometric morphometric analyses. Three decision trees were created from quantitative and qualitative characters using classification and regression tree analyses. The best-performing tree used quantitative and qualitative characters describing shell-only scenarios and obtained 80.6% correct classification on terminal nodes. Canonical variates analysis on geometric morphometric shell data revealed large morphological overlap between species. Goodall's F-tests between pairs of species revealed significant differences (a=0.05) between all but one species pairs; however, examination of landmarks on shells concluded large overlap of landmarks between species pairs. Lack of morphologically distinct characters to readily identify these phylogenetically distinct species indicates large morphological overlap among these species. Biologists need to be cognizant that morphologically cryptic species may exist in systems often explored. Three dichotomous keys were created from classification trees to identify select individuals in the genera Fusconaia, Pleurobema, and Pleuronaia; two of these keys, one for shells and one for live mussels were tested by participants with varying mussel identification skills to represent novices and experts. Both keys used continuous (quantitative) and categorical variables to guide participants to identifications. Novices, who had no prior mussel identification experience, correctly identified mussels with a 50% accuracy using the shell key and with a 51% accuracy using the live key. Experts, who had at least three years of experience identifying mussels, correctly identified mussels with a 58% accuracy using the shell key and with a 68% accuracy using the live key; however one expert noted that they did not use the live key to correctly identify one mussel. Morphological overlap of variables between mussels likely resulted in failure to consistently identify mussels correctly. Important management decisions and project implementations require accurate assessment of species' localities and populations. Incorrect species identification could hinder species' recovery efforts or prevent projects that otherwise could have continued if species are misidentified. If a mussel collection is thought to be a new record or could affect a project, I recommend that molecular genetic identifications be used to verify the species identity.
Assessment of Mussel Declines in the Clinch and North Fork Holston Rivers Using Histological Evaluations of Vital Organs
Rogers, Jennifer J. (Virginia Tech, 2015-08-31)
The Clinch River (CR) and North Fork Holston River (NFHR) contain some of the most diverse freshwater mussel assemblages in the United States; however, both rivers are experiencing declines in mussel populations. The first component of this study used histological evaluations and water quality data to determine whether mussels were negatively impacted in the CR zone of decline (ZD) and to inform future management of freshwater mussels in the river. In the 91 kilometer (km) section from Carbo, Virginia (CRKM 431) downstream to Speers Ferry, Virginia (CRKM 340), referred to as the ZD, mussel density decreased >90% from 1979 to 2014 at key sites such as Semones Island (CRKM 378.3) and Pendleton Island (CRKM 364.2). Laboratory propagated mussels were placed in cages in the river for one year from June 2012 to May 2013 at four sites within the ZD and four sites in reaches where mussel populations remain stable or are increasing, a zone of stability (ZS). The survival, growth and histological results indicated that there are continuing impacts to mussels in the ZD. Research investigating impacts to the ZD and methods to improve water quality in this zone are needed. The laboratory component of this study examined sublethal effects of potassium (K⁺), chloride (Cl⁻), and un-ionized ammonia (NH₃-N) on mussel tissues at concentrations relevant to those found in the NFHR. Historical industrial activities at Saltville, Virginia, as well as continued pollution of the NFHR from chemical waste ponds at this location, are believed to be significant contributors to mussel declines. Contaminant seepages from the waste ponds that include Cl⁻, K⁺, and NH₃-N have been shown to be toxic to adult and juvenile mussels. A three-month laboratory study was conducted to assess impacts to organ tissues (gills, digestive glands, kidneys, and gonads) of adult Villosa iris exposed to environmentally relevant concentrations of K⁻ (4 and 8 mg/L), Cl⁻ (230 and 705 mg/L), and NH₃-N (0.014 and 0.15 mg/L) using histological evaluations. No detectable differences were observed among the histological endpoints from mussels held in treatments and control (p>0.05). The study design was modified and repeated using increased concentrations of K⁺ (8, 16, and 32 mg/L) and Cl⁻ (705, 1410, and 2820 mg/L) for a two-month exposure period. Due to issues with maintaining NH3-N in mussel holding chambers, the second study did not the second study did not include NH₃-N exposures. Control mussels in both studies had a higher abundance of lipofuscin in kidneys and degraded cytoplasm in the digestive gland diverticula compared to baseline mussels, indicating that captivity influenced mussel tissues. Future studies are needed to more thoroughly address these captivity effects. Both survival and histological data in the second test showed a significant negative effect of the increased concentrations of Cl⁻ and K⁻, which were representative of those found at some sites in the NFHR downstream of Saltville, Virginia.
Characterization of the molecular genetic variation in wild and farmed Nile tilapia Oreochromis niloticus in Ghana for conservation and aquaculture development
Anane-Taabeah, Gifty (Virginia Tech, 2019-02-01)
The Nile tilapia Oreochromis niloticus is native to Africa and middle East, and is an important source of nutrition for many in sub-Saharan Africa. Understanding the genetic diversity within and differentiation among wild populations can help identify O. niloticus populations that are imperiled and require directed management, especially because of increasing threats to the species' long-term persistence in the wild, including habitat destruction, overfishing, climate change, and hybridization with farmed populations. Knowledge of the genetic variation among wild populations also can contribute to foundation and selection of genetically diverse populations for aquaculture. I assessed the genetic variation among tilapia populations using fin-clips collected between December 2014 and July 2017 from 14 farmed sources, mostly originating from cage farms on the Volta Lake, and 13 wild sources from nine river basins in Ghana. I also conducted a laboratory growth experiment in Ghana with two wild populations to evaluate the tolerance of different genotypes to high temperatures, to inform their development for aquaculture in West Africa. I found that pure O. niloticus populations persist in the wild but some have been extensively introgressed with the closely related species, O. aureus, which has not previously been documented in Ghana. Additionally, some wild populations appear to have recently declined significantly in numbers, likely due to overfishing and habitat modification, the latter primarily as a result of illegal alluvial mining ongoing in Ghana. Analysis of the farmed populations revealed that at least two farms were growing the unapproved genetically improved farmed tilapia (GIFT) and related strains, and that escaped individuals are admixed into some wild populations. The results of my laboratory experiment showed that O. niloticus populations occurring in northern Ghana already may be adapted to warmer temperatures and could be developed and used purposefully in aquaculture, taking advantage of their adaptation. To protect remnant pure O. niloticus populations in the wild, timely conservation decisions should be made and implemented. Protecting wild O. niloticus populations also would ensure that pure germplasms are available to develop aquaculture stocks from native populations.
Chronic Toxicity of Trace-Metal Mixtures to Juvenile Freshwater Mussels
Timpano, Anthony J.; Jones, Jess W. (Virginia Tech. Powell River Project, 2019)
Funding from Powell River Project in FY2019 provided partial support for completion of data analysis and communication of findings from a prior ecotoxicological study funded by The Nature Conservancy (TNC). Our communications included oral presentations at two scientific meetings, three webinar presentations to federal agency staff, preparation of a final technical report, and preparation of a manuscript for publication in a peer-reviewed journal. Completed analyses of study results and sharing of findings should aid efforts to conserve and restore mussel populations in the Clinch and Powell rivers, thus advancing the environmental science mission of the Powell River Project to enhance management and restoration of environmental resources affected by mining in the Appalachian coalfield. This Annual Report contains a summary of research findings from the study supported by TNC, followed by a summary of activities described above that were supported directly by Powell River Project.
Combined effects of copper, nickel, and zinc on growth of a freshwater mussel (Villosa iris) in an environmentally relevant context
Timpano, Anthony J.; Jones, Jess W.; Beaty, Braven; Hull, Matthew; Soucek, David J.; Zipper, Carl E. (Elsevier, 2022-01)
Trace metals rarely contaminate freshwaters independently, hence regulatory limits based on single-metal toxicity may be underprotective of aquatic life. This could be especially the case for rare and sensitive fauna like freshwater mussels, such as those suppressed in the Clinch and Powell Rivers in eastern USA where trace metals are long-term contaminants but at concentrations below regulatory limits. We hypothesized metal mixtures may be exerting combined effects on mussels, resulting in greater toxicity than would be predicted based on single-metal exposures. To test that hypothesis, we conducted two experiments exposing juvenile rainbow mussels (Villosa iris) for 42 days to dissolved copper, nickel, and zinc, individually and in three-metal mixtures, in an environmentally-relevant context of water with chemistry (hardness 155 mg/L as CaCO3, dissolved organic carbon 1.7-2.3 mg/L, pH 8.4) similar to that of the Clinch River, which receives alkaline mine drainage. We used a toxic unit approach, selecting test concentrations based on literature values for the lower of 28-day survival or growth (length) effect concentrations for Villosa iris or Lampsilis siliquoidea (fatmucket). Our first experiment confirmed survival and growth effects when acute and chronic water quality criteria, respectively, are approached and/or exceeded. Our second experiment, at lower concentrations, showed no effects on survival but combined effects on growth were evident: a mixture of Cu, Ni, and Zn (7.2 +/- 1.2, 65.3 +/- 6.1, 183 +/- 32 mu g/L, respectively) inhibited growth (dry weight) by 95% versus 73%, 74%, and 83% inhibition for single-metal exposures to Cu, Ni, and Zn of similar concentration (8.0 +/- 1.1, 63.5 +/- 4.8, 193 +/- 31 mu g/L, respectively). Furthermore, a mixture of Cu, Ni, and Zn with individual concentrations 21%, 29%, and 37% of their water quality criteria (3.4 +/- 1.2, 21.8 +/- 1.8, and 62.1 +/- 8.4 mu g/L, respectively) inhibited growth (dry weight) by 61% relative to controls. Our observation of combined effects suggests that regulatory limits based on single-metal toxicity may be underprotective of freshwater mussels when multiple metals are present.
A Comparison of Systematic Quadrat and Capture-Mark-Recapture Sampling Designs for Assessing Freshwater Mussel Populations
Carey, Caitlin; Jones, Jess W.; Butler, Robert S.; Kelly, Marcella J.; Hallerman, Eric M. (MDPI, 2019-08-07)
Our study objective was to compare the relative effectiveness and efficiency of quadrat and capture-mark-recapture (CMR) sampling designs for monitoring mussels. We collected data on a recently reintroduced population of federally endangered Epioblasma capsaeformis and two nonlisted, naturally occurring species—Actinonaias pectorosa and Medionidus conradicus—in the Upper Clinch River, Virginia, over two years using systematic quadrat and CMR sampling. Both sampling approaches produced similar estimates of abundance; however, precision of estimates varied between approaches, years, and among species, and further, quadrat sampling efficiency of mussels detectable on the substrate surface varied among species. CMR modeling revealed that capture probabilities for all three study species varied by time and were positively associated with shell length, that E. capsaeformis detection was influenced by sex, and that year-to-year apparent survival was high (>96%) for reintroduced E. capsaeformis. We recommend that monitoring projects use systematic quadrat sampling when the objective is to estimate and detect trends in abundance for species of moderate to high densities (>0.2/m²), whereas a CMR component should be incorporated when objectives include assessing reintroduced populations, obtaining reliable estimates of survival and recruitment, or producing unbiased population estimates for species of low to moderate densities (≤0.2/m²).
Description of the mantle lure and novel mimicry of the endangered Cumberlandian Combshell (Epioblasma brevidens) in the Clinch River, eastern United States
Jones, Jess W.; Taylor, Zachary; Lane, Timothy (Wiley, 2023-03)
The Cumberlandian Combshell (Epioblasma brevidens) is an endangered freshwater mussel endemic to the Tennessee and Cumberland River drainages, major tributaries of the Ohio River of the eastern United States. We conducted mask and snorkel surveys in May and June of 2021 and 2022 to locate, observe, photograph, and video female E. brevidens to document their unique mantle lures at sites in the Clinch River in Tennessee and Virginia. The mantle lure is morphologically specialized mantle tissue that mimics prey items of the host fish. The mantle lure of E. brevidens appears to mimic four distinct characteristics of the reproductive anatomy of the underside (ventral) of a gravid female crayfish, to include: (1) the external apertures of the oviducts located on the base of the third pair of walking legs, (2) crayfish larvae still encased in the egg membrane, (3) pleopods or claws, and (4) postembryonic eggs. Surprisingly, we observed males of E. brevidens displaying mantle lures that were anatomically complex and closely resembled the female mantle lure. The male lure similarly mimics oviducts, eggs, and pleopods but is diminutive (2-3 mm smaller in length or diameter) to those same structures in females. We describe for the first time the mantle lure morphology and mimicry of E. brevidens, showing its close resemblance to the reproductive anatomy of a gravid female crayfish, and a novel form of mimicry in males. To our knowledge, mantle lure displays in males have not been previously documented in freshwater mussels.
Development and characterization of microsatellite loci in the endangered catspaw, Epioblasma obliquata (Bivalvia: Unionidae)
Ortiz, Katlyn; Jones, Jess W.; Hallerman, Eric M. (2022)
The endangered Catspaw, Epioblasma obliquata, is restricted to one known reproducing population in Killbuck Creek, Coshocton County, Ohio. Little is known about the genetic diversity of this small population, and such information is needed to help inform recovery planning. We nonlethally sampled 44 individuals of E. obliquata using buccal swabs, from which we developed and characterized 14 polymorphic microsatellite loci. Significant deviations from Hardy–Weinberg Equilibrium (HWE), showing deficiencies in heterozygotes, were observed at 6 of the 14 loci, and linkage disequilibrium (LD) was observed at 9 (~10%) of 91 possible pairwise comparisons among loci. Allelic diversity ranged from 2 to 15 alleles per locus and averaged 7.6 alleles per locus. Observed heterozygosity per locus ranged from 0.091 to 1.000 and averaged 0.674. Possible explanations for deviations from HWE and LD could be from loci located close together on the same chromosome, segregation of null alleles, family structure within the small population, population bottlenecks, inbreeding, hermaphroditic reproduction, or some combination of these factors. Managers can use these microsatellite markers to assess and monitor genetic diversity in the remaining wild population in Killbuck Creek, prospective broodstock, hatchery-reared progeny, and reintroduced populations founded to promote recovery of the species.
Development of Molecular and Morphological Resources for Identification and Monitoring of Freshwater Mussel Species in the Genera Fusconaia and Pleurobema in the Green River, Kentucky
Hyde, Miluska Olivera (Virginia Tech, 2021-01-11)
Freshwater mussel species in the genera Fusconaia and Pleurobema are particularly challenging to identify in the field. In this study, mussels from these genera were collected from the Green River, Kentucky for genetic and morphological analyses. I used molecular markers to detect any cryptic species within these genera and to test for genetic differentiation between two closely related nominal taxa P. rubrum and P. sintoxia using both mitochondrial (ND1, COI, 16S rRNA) and nuclear (ITS1) DNA sequences. After species identification, I used microsatellite DNA markers to estimate genetic diversity and effective population sizes (Ne) of species of Pleurobema. I used microsatellite primers that were developed for P. clava and P. pyriforme in previous studies, as well as microsatellites that I developed for P. plenum. Finally, I assessed morphological variation in my study species and developed dichotomous keys for the identification of both live mussels and shells. My results suggest that P. rubrum and P. sintoxia are the same species based on the mitochondrial DNA analyses, as there were few genetic differences between them. My results showed phylogenetically distinct lineages for F. flava, F. subrotunda, P. cordatum and P. plenum but no cryptic species were detected in the Green River. Current and contemporary Ne showed that these species have large population sizes that should allow for avoiding inbreeding and maintaining their evolutionary potential. Large genetic diversity as well as long-term effective population size could be the result of these species historically occurring as much larger assemblages that extended into the Ohio River and its numerous tributaries. The last objective was to assess morphometrical differences among these species. Using Canonical Variate Analysis, I found discernable morphological differences between the investigated species of Fusconaia and Pleurobema. The two Fusconaia species were morphologically different from the Pleurobema species. However, the Canonical Variate Analysis did not show differences among the Pleurobema species. I used decision tree analysis to develop a dichotomous tree, and random forest analysis was used to aid in the development of a dichotomous key by finding the most important diagnostic characters to distinguish these mussels. I then used the less subjective and easier to identify characters for the development of my dichotomous keys for live mussels and shells. However, both keys need to be tested in the field to determine their effectiveness. I could not separate P. rubrum and P. sintoxia mussels for morphometric analysis due to the lack of genetic differentiation and the inconsistent identification by the experts. However, I did describe a few individuals that look like P. rubrum and P. sintoxia to the eye of the experts. The description of these individuals matched previous descriptions of these mussels. Future studies need to assess taxonomic relationships among these species using genomics approaches, which might result in better node resolution. High genetic diversity and large effective population numbers for Pleurobema species suggest that these species' populations are genetically healthy. However, these results need to be interpreted carefully, and I therefore recommend additional studies to assess life history, habitat, host-fish availability, and current reproduction of these mussels in the Green River.
An Evaluation of Population Restoration and Monitoring Techniques for Freshwater Mussels in the Upper Clinch River, Virginia, and Refinement of Culture Methods for Laboratory-Propagated Juveniles
Carey, Caitlin (Virginia Tech, 2013-12-08)
From 2006-2011, four population reintroduction techniques were applied to three sites within a reach of the upper Clinch River in Virginia designated suitable for population restoration of the federally endangered oyster mussel (Epioblasma capsaeformis). These techniques were: 1) translocation of adults (Site 1), 2) release of laboratory-propagated sub-adults (Site 1), 3) release of 8-week old laboratory-propagated juveniles (Site 2), and 4) release of stream-side infested host fishes (Site 3). Demographic data were collected in 2011 and 2012 by systematic quadrat and capture-mark-recapture sampling to assess reintroduction success, evaluate reintroduction techniques, and compare survey approaches for monitoring freshwater mussels. Estimates of abundance and density of translocated adults ranged from 450-577 individuals and 0.09-0.11/m2 in 2011, and 371-645 individuals and 0.07-0.13/m2 in 2012. Estimates of abundance and density of laboratory-propagated sub-adults ranged from 1,678-1,943 individuals and 0.33-0.38/m2 in 2011, and 1,389-1,700 individuals and 0.27-0.33/m2 in 2012. Additionally, three recruits were collected at Site 1. No E. capsaeformis were collected at Sites 2 and 3. Capture-mark-recapture sampling produced similar mean point estimates as systematic quadrat sampling, but with typically more precision. My results indicated that the release of larger individuals (>10 mm) is the most effective technique for restoring populations of E. capsaeformis, and that systematic quadrat and capture-mark-recapture sampling have useful applications in population monitoring that are dependent on project objectives. Systematic quadrat sampling is recommended when the objective is to simply estimate and detect trends in population size for species of moderate to larger densities (>0.2/m2). Capture-mark-recapture sampling should be used when objectives include assessing a reintroduced population of endangered species or at low density, obtaining precise estimates of population demographic parameters, or estimating population size for established species of low to moderate density (0.1-0.2/m2). The ability to grow endangered juveniles to larger sizes in captivity requires improving grow-out culture methods of laboratory-propagated individuals. A laboratory experiment was conducted to investigate the effects of temperature (20-28 C) on growth and survival of laboratory-propagated juveniles of the Cumberlandian combshell (Epioblasma brevidens), E. capsaeformis, and the wavyrayed lampmussel (Lampsilis fasciola) in captivity. Results indicated that 26 C is the optimum temperature to maximize growth of laboratory-propagated juveniles in small water-recirculating aquaculture systems. Growing endangered juveniles to larger sizes will improve survival in captivity and after release into the wild. As a result, hatcheries can reduce the time that juveniles spend in captivity and thus increase their overall production and enhance the likelihood of success of mussel population recovery efforts by federal and state agencies, and other partners.
Evaluation of the Certus, Inc. and Lone Mountain Processing, Inc. Natural Resource Damage Assessment and Restoration Cases to Restore Mussels in the Clinch and Powell Rivers in Virginia and Tennessee
Hyde, John Murray (Virginia Tech, 2022-01-18)
Freshwater mussels are particularly susceptible to injury from exposure to hazardous substances due to their sessile nature and filter feeding biology. There have been various Natural Resource Damage Assessment and Restoration (NRDAR) cases in the United States involving injury to freshwater mussels due to releases of hazardous substances into rivers and streams. Restoration of mussels in these cases typically involves propagation of mussels at a hatchery facility and their subsequent stocking or release at restoration sites. However, determination of the services lost due to injury to mussel populations and the appropriate level of restoration (and associated costs) to recover those losses has varied among NRDAR cases. Standardized methods would facilitate injury determination and restoration planning for future cases involving injury to mussels. The purpose of this research was to use two of the earliest and largest NRDAR cases (Certus, Inc. and Lone Mountain Processing, Inc. (LMPI)) involving injury to mussels to: 1) determine whether restoration for these cases was sufficient and 2) analyze restoration efforts for application in future NRDAR cases (i.e., lessons learned and development of standardized methods). This study represents the first evaluation of mussel restoration efforts in a NRDAR context. In general, 4.8% to 6.1% of juvenile mussels that excysted from host fishes in the hatchery survived to be eventually released at restoration sites. Further, based on expected survival and recruitment rates of released mussels, monitoring of restoration sites found 43% to 15% of the expected number of mussels. Understanding reasons for this discrepancy between expected and estimated survival is critical for determining the level of restoration success. If released mussels are either establishing and/or recruiting outside of monitoring area but otherwise alive and breeding, then they should count towards successful restoration. In contrast, if released mussels have either high mortality over time or are dying shortly after release, then expected gains from these mussels should not count towards successful restoration. I developed a mussel-specific Resource Equivalency Analysis (REA) for use in future NRDAR cases that compares the loss of services, using Discounted Mussel Years (DMYs) as units, to the expected gain in services from restoration. Applying this analysis to the Certus and LMPI NRDAR cases suggests that mussel restoration was successful (i.e., expected DMYs gained are greater than those lost), even when it was assumed that 75% of released mussels were dying after being released at restoration sites. Finally, a cost analysis of two mussel propagation facilities found that the yearly cost per mussel released at a restoration site ranged from $4.36 to $96.48. The suite of species propagated each year varied. As some species are more difficult to propagate than others, the cost per mussel varied widely. These data will facilitate the determination of restoration costs in future cases. Together, this information provides a starting point for consistently estimating restoration effort and costs for future NRDAR cases involving freshwater mussels.
Evaluation of the Effects of Mining Related Contaminants on Freshwater Mussels (Bivalvia: Unionidae) in the Powell River of Virginia and Tennessee
Phipps, Andrew Thomas (Virginia Tech, 2019-06-10)
The Powell River is located in southwestern Virginia and northeastern Tennessee, USA and supports a diverse freshwater mussel assemblage of 29 extant species. Throughout the river major ion and trace element concentrations have increased over the last several decades due to extensive surface coal-mining in the headwaters in Virginia. As watershed area affected by mining has increased, mussel populations have declined, especially in Virginia where populations have been severely reduced or extirpated. The upper watershed now has been extensively mined for coal, causing widespread effects on water and sediment quality. To investigate how mining may be affecting mussel populations, I first conducted a laboratory bio-assay to assess the effects of elevated major ions and the trace element nickel (Ni) on growth and survival of juvenile mussels, including one common species (Villosa iris) and one endangered species (Epioblasma capsaeformis). No significant differences in overall survival between treatments and control were observed for either species over a 70 day test period. Total growth was not significantly different between treatments and control for either species. However, overall growth varied significantly (p=0.009) between species, with V. iris (2.49 mm) exhibiting greater growth compared to E. capsaeformis (1.97 mm). Results suggest that major ion chronic toxicity alone or in combination with Ni at or below my test concentration is not a likely source of toxicity to juvenile mussels in the Powell River. Secondly, I conducted a field study in the Powell River using two cohorts of juveniles of Villosa iris to assess the effects of trace elements and PAH contamination related to mining on mussel survival and growth. Specific conductance was elevated throughout the Powell River, where site means ranged from 450 to 900 µS/cm. While mortality was high at all eight sites it was not significantly different among these sites (p>0.28); however, growth of juvenile mussels was significantly higher (p<0.001) in the lower river in Tennessee. Regression analysis showed significant relationships (p<0.001) of river kilometer with temperature, specific conductance, and aqueous major ion concentrations. A principal component analysis (PC) was conducted on all trace element data. Growth of Cohort 1 on Day 106 was best explained by the PC dominated by aqueous major ion concentrations (p<0.0001, R2= 0.65) and growth of Cohort 2 on Day 106 was best explained by specific conductance (p<0.0001, R2= 0.68). Growth of Cohort 2 at Day 423 was best explained by tissue trace element concentration PC1 and PC2 (p<0.0001, R2= 0.73). This study suggests major ions and select trace elements (Ba, Ni, Fe, Se, and Sr) in the Powell River are negatively affecting the growth of freshwater mussels and that the source of these contaminants is primarily from mining in the headwaters.
Factors Affecting Survival and Growth of Juvenile Freshwater Mussels Cultured in Recirculating Aquaculture Systems
Jones, Jess W.; Mair, Rachel; Neves, Richard (North American Journal of Aquaculture, 2005)
Seasonal differences in glochidial maturity, substrate, and diet were studied to determine how these factors affect the survival and growth of juvenile freshwater mussels. Comparisons were made between juveniles produced in the fall and spring of the year; cultured in sediment, sand, or without substrate; and fed either of two species of small (5–10-mm) green algae. The survival and growth of endangered juveniles of oyster mussel Epioblasma capsaeformis were compared with those of a common, seemingly more robust species, the rainbow mussel Villosa iris. The growth of rainbow mussel juveniles was significantly greater than that of oyster mussel juveniles (P , 0.001). The survival and growth of oyster mussel juveniles were significantly greater when propagated in the spring, that is, when glochidia were mature and would normally be released, than in fall (P , 0.001). Survival and growth of juveniles of both species were significantly greater when they were cultured in a sediment substratum rather than sand or no substratum (P , 0.001). No differences (P . 0.05) were observed in survival and growth of juveniles fed algal species Neochloris oleoabundans or Nannochloropsis oculata. In the spring of the year, juvenile oyster mussels achieved a survival of 29.6% and mean length of 664 micrometers at 60 d of age, whereas at the same age rainbow mussel juveniles exhibited a survival of 25.1% and a mean length of 1,447 micrometers.
Genetic and morphological characterization of the freshwater mussel clubshell species complex (Pleurobema clava and Pleurobema oviforme) to inform conservation planning
Morrison, Cheryl L.; Johnson, Nathan A.; Jones, Jess W.; Eackles, Michael S.; Aunins, Aaron W.; Fitzgerald, Daniel B.; Hallerman, Eric M.; King, Tim L. (Wiley, 2021-10-20)
The shell morphologies of the freshwater mussel species Pleurobema clava (federally endangered) and Pleurobema oviforme (species of concern) are similar, causing considerable taxonomic confusion between the two species over the last 100 years. While P. clava was historically widespread throughout the Ohio River basin and tributaries to the lower Laurentian Great Lakes, P. oviforme was confined to the Tennessee and the upper Cumberland River basins. We used two mitochondrial DNA (mtDNA) genes, 13 novel nuclear DNA microsatellite markers, and shell morphometrics to help resolve this taxonomic confusion. Evidence for a single species was apparent in phylogenetic analyses of each mtDNA gene, revealing monophyletic relationships with minimal differentiation and shared haplotypes. Analyses of microsatellites showed significant genetic structuring, with four main genetic clusters detected, respectively, in the upper Ohio River basin, the lower Ohio River and Great Lakes, and upper Tennessee River basin, and a fourth genetic cluster, which included geographically intermediate populations in the Ohio and Tennessee river basins. While principal components analysis (PCA) of morphometric variables (i.e., length, height, width, and weight) showed significant differences in shell shape, only 3% of the variance in shell shape was explained by nominal species. Using Linear Discriminant and Random Forest (RF) analyses, correct classification rates for the two species' shell forms were 65.5% and 83.2%, respectively. Random Forest classification rates for some populations were higher; for example, for North Fork Holston (HOLS), it was >90%. While nuclear DNA and shell morphology indicate that the HOLS population is strongly differentiated, perhaps indicative of cryptic biodiversity, we consider the presence of a single widespread species the most likely biological scenario for many of the investigated populations based on our mtDNA dataset. However, additional sampling of P. oviforme populations at nuclear loci is needed to corroborate this finding.
Genetic Structure of Maryland Brook Trout Populations: Management Implications for a Threatened Species
Morgan, Raymond P. II; Kazyak, David C.; King, Tim L.; Lubinski, Barbara A.; Sell, Matthew T.; Heft, Alan A.; Jones, Jess W. (2021-03-23)
Brook Trout Salvelinus fontinalis have declined across their native range due to multiple anthropogenic factors, including landscape alteration and climate change. Although coldwater streams in Maryland (eastern United States) historically supported significant Brook Trout populations, only fragmented remnant populations remain, with the exception of the upper Savage River watershed in western Maryland. Using microsatellite data from 38 collections, we defined genetic relationships of Brook Trout populations in Maryland drainages. Microsatellite analyses of Brook Trout indicated the presence of five major discrete units defined as the Youghiogheny (Ohio), Susquehanna, Patapsco/Gunpowder, Catoctin, and Upper Potomac, with a distinct genetic subunit present in the Savage River (upper Potomac). We did not observe evidence for widespread hatchery introgression with native Brook Trout. However, genetic effects due to fragmentation were evident in several Maryland Brook Trout populations, resulting in erosion of diversity that may have negative implications for their future persistence. Our current study supplements an increasing body of evidence that Brook Trout populations in Maryland are highly susceptible to multiple anthropogenic stresses, and many populations may be extirpated in the near future. Future management efforts focused on habitat protection and potential stream restoration, coupled with a comprehensive assessment framework that includes genetic considerations, may provide the best outlook for Brook Trout populations in Maryland.
Genetics, demography and modeling of freshwater mussel (Bivalvia: Unionidae) populations in the Clinch River, U.S.A.
Jones, Jess W. (Virginia Tech, 2009-02-06)
Genetic variation was examined in two endangered mussel species, Epioblasma brevidens and E. capsaeformis, and a common species Lampsilis fasciola, in the Clinch River, TN, by screening mitochondrial DNA (mtDNA) sequences and nuclear DNA microsatellites. These species use fish hosts with varying dispersal capabilities, ranging from low, moderate, and high, respectively. Patterns of mtDNA polymorphism exhibited different trends for long-term population sizes for each species during the Holocene (~10,000 ya to present); namely, E. brevidens has declined over time, E. capsaeformis has remained stable, and L. fasciola has expanded. Long-term effective population size (Ne) was smallest in E. brevidens, intermediate in E. capsaeformis, and highest in L. fasciola. Moderately diverged mtDNA lineages, perhaps indicative of secondary contact, were observed in E. brevidens and E. capsaeformis. High levels of gene flow (Nm) were estimated among demes of L. fasciola using traditional F-statistics and likelihood estimates of Nm, whereas such metrics were lower in E. brevidens and E. capsaeformis. Data are consistent with population dynamics and life history traits of each species and their fish hosts. Age, shell growth, and population demography of Epioblasma brevidens, E. capsaeformis, and Lampsilis fasciola were studied from 2004-2007 in a 32-km reach of the Clinch River, TN. Observed maximum age and length of E. brevidens was 28 y and 71.5 mm for males and 11 y and 56.6 mm for females; of E. capsaeformis, 12 y and 54.6 mm for males and 9 y and 48.6 mm for females; and of L. fasciola, 45 y and 91.3 mm for males and 13 y and 62.6 mm for females. For all three species, observed maximum age and length was greater among males than females. Estimated population size in this river reach was approximately 43,000 individuals for E. brevidens, 579,000 individuals for E. capsaeformis, and 30,000 individuals for L. fasciola. Mean recruitment y-1 of 1 y-old E. brevidens ranged from 7.1% to 20%, of E. capsaeformis from 4.0% to 32.4%, and of L. fasciola from 5.8% to 25.6%. Population growth rate y-1 was 24.9% for E. brevidens, 34.6% for E. capsaeformis, and -22.4% for L. fasciola. Mortality rates of females were higher than for males of E. capsaeformis and L. fasciola, but not E. brevidens. Juvenile mussels were collected but temporally and spatially variable in occurrence, and a significant component of the age-class structure of all three species. Recruitment was very high during 2006-2007 for E. capsaeformis and other species, likely due to low river discharges in the spring-summer of 2005-2007. Surplus individuals of E. brevidens and E. capsaeformis are currently available to conduct translocations for restoration purposes. Population modeling of Epioblasma brevidens and E. capsaeformis in the Clinch River was conducted to determine suitable harvest levels for translocation of sub-adults and adults, and to determine quantitative criteria for evaluating performance and recovery of extant and reintroduced populations. For both species, the recommended annual harvest was <1% of local population size to minimize risk of decline. Reintroduction modeling indicated that size of the initial population created during a 5 y build-up phase greatly affected final population size at 25 y, being similar to size at the end of the build-up phase, especially when expected growth rate was low, (e.g., 1-2%). Excluding age-0 individuals, age-1 juveniles or recruits on average comprised approximately 11% and 15% of a stable population of each species, respectively. The age-class distribution of a stable or growing population was characterized by multiple cohorts, to include juvenile recruits, sub-adults, and adults. Molecular genetic and demographic data indicated that the ratio of Ne/Nc was ~5% for both species. Based on this ratio and predicted declines of genetic variation at different population sizes, target sizes for reintroduced or recovered populations of each species should be ≥5,000 individuals (Ne=250) and ≥10,000 individuals (Ne=500), respectively, and should be comprised of multiple smaller demes spread throughout a river. Populations of both species are currently large enough to sustain harvest for translocation and reintroduction purposes, offering an effective species recovery strategy.
Histological evaluations of organ tissues reveal sublethal effects in a freshwater mussel (Villosa iris) exposed to chloride and potassium concentrations below benchmark estimates
Rogers, Jennifer J.; Henley, William F.; Weberg, Amanda G.; Jones, Jess W.; Cope, W. Gregory (Elsevier, 2023-05)
Salinization of freshwater ecosystems due to anthropogenic sources will increasingly impact biodiversity. An example of point-source industrial salinization has occurred from historical activities at a U.S. Environmental Protection Agency Superfund Site near Saltville, Virginia USA and its associated chemical waste ponds adjacent to the North Fork Holston River. These point source discharges are documented contributors to mussel declines, partially due to high concentrations of chloride (Cl-, <= 26,000 mg Cl-/L) and potassium (K+, <= 97 mg K+/L). During a chronic 61-day laboratory study, Rainbow mussels, Villosa iris, were exposed to concentrations of Cl-(0, 416, 831, and 1,663 mg/L) and K+ (0, 4, 8, and 17 mg/L) to determine effects on survival and organ tissues. All test mussels died by day-2 in the 1,663 mg Cl-/L exposure, and 50% of mussels died by day-13 in the 17 mg K+/L concentration. Significantly greater abundances of tissue abnormalities were observed in digestive glands and kidneys with exposures to the 4 and 8 mg/L concentrations of K+ versus the control, and significantly greater abundances of lesions in kidneys were observed in the 416 and 831 mg Cl-/L concentrations compared to the control. The sublethal effects to digestive glands and kidneys were below reported effect (EC50, 20, 10 and LOEC) concentrations. Significant histological differences between control and baseline (day-0 sample) mussels were observed, suggesting the need for further study on the effects of captivity during longer-term laboratory experiments.
A Holistic Approach to Taxonomic Evaluation of Two Closely Related Endangered Freshwater Mussel Species, the Oyster Mussel (Epioblasma capsaeformis) and Tan Riffleshell (Epioblasma florentina walkeri) (Bivalvia: Unionidae)
Jones, Jess W. (Virginia Tech, 2004-03-19)
Primers for 10 polymorphic DNA microsatellite loci were developed and characterized for the endangered oyster mussel Epioblasma capsaeformis from the Clinch River, TN. Microsatellite loci also were amplified for individuals collected from the following additional populations or species: (1) E. capsaeformis from Duck River, TN; (2) E. florentina walkeri from Indian Creek, upper Clinch River, VA; (3) E. florentina walkeri from Big South Fork Cumberland River, TN; and (4) E. torulosa rangiana from Allegheny River, PA. Allelic diversity ranged from 9-20 alleles/locus, and averaged 13.6/locus for all 5 populations investigated. Average expected heterozygosity (HE) per locus ranged from 0.78-0.92, and averaged 0.86. A genetic characterization of extant populations of E. capsaeformis and E. florentina walkeri was conducted to assess taxonomic validity and to resolve conservation issues related to recovery planning. These mussel species exhibit pronounced phenotypic variation, and are difficult to characterize phylogenetically using DNA sequences. Monophyletic lineages, congruent with phenotypic variation among species, were obtained only after extensive analysis of combined mitochondrial (1378 bp of 16S, cytochrome-b, ND1) and nuclear (515 bp of ITS-1) DNA sequences. In contrast, analysis of variation at 10 hyper variable DNA microsatellite loci showed moderate to highly divergent populations based on FST values, which ranged from 0.12-0.39. Quantitative genetic variation was observed in fish host specificity, with transformation success of glochidia of E. capsaeformis significantly greater (p<0.05) on the greenside darter Etheostoma blennioides, and that of E. f. walkeri significantly greater (p<0.05) on the fantail darter E. flabellare. Lengths of glochidia differed significantly (p<0.001) between species, with sizes ranging from 241-272 μm. Underwater photographs of mantle-pads and micro-lures of female mussels documented fixed phenotypic variation between species. The texture and color of the mantle-pad of E. capsaeformis is smooth and bluish-white, while that of E. f. walkeri is pustuled and brown, with tan mottling. Based on extensive molecular, morphological, and life history data, a population of E. capsaeformis from the Duck River, TN is described and proposed as a separate species, and a population of E. f. walkeri from the upper Clinch River, VA is described and proposed as a separate subspecies. Genetic management guidelines were developed to assess taxonomic status, genetic variation of donor-recipient populations targeted for augmentation, and field and laboratory protocols to maximize genetically effective population size, minimize genetic changes in captive-reared progeny, and prevent the release of juvenile mussels into non-native drainages. A pragmatic approach to species recovery is advocated; one that incorporates the principles of conservation genetics into breeding programs, but prioritizes the immediate demographic needs of critically endangered mussel species.
Integrative Science and Solutions for Freshwater Systems Concept Paper - A plan to build a signature-strength in Freshwater Systems
Benham, Brian L.; Czuba, Jonathan A.; Hession, W. Cully; Krometis, Leigh-Anne H.; Scott, Durelle T.; Stephenson, Stephen Kurt; Thompson, Theresa M.; Bork, Dean R.; Hester, Erich T.; Polys, Nicholas F.; Ivory, James Dee; Angermeier, Paul L.; Castello, Leandro; Dolloff, C. Andrew; Emrick, Verl III; Jones, Jess W.; McLaughlin, Daniel L.; Meyers, R. B.; Orth, Donald J.; Schoenholtz, Stephen H.; Snodgrass, Joel W.; Hotchkiss, Erin R.; Smith, Eric P. (Virginia Tech, 2017-05-15)
Virginia Tech is poised to become a global leader in the pursuit and application of new knowledge to inform management and restoration of waterbodies and their watersheds. Despite our notable strengths in specific disciplines, we have not yet facilitated nor nurtured an interdisciplinary program whereby a holistic perspective of freshwater systems can permeate into VT-shaped students and bridge the gaps among water-relevant biophysical, social sciences, and the arts. We know of no other major research university with a signature-strength in integrated freshwater systems science...
Magellan mussels Aulacomya atra from the South African coast show high diversity within populations but a lack of geographic differentiation
Grobler, J. P.; Zhao, Z.; Jones, Jess W.; Kotze, A. (Taylor & Francis, 2023-01-02)
The Magellan mussel Aulacomya atra is a bivalve mollusc found along parts of the South African and Namibian coastline. Its numbers were low historically compared with other indigenous species but have decreased further since the 1970s owing to habitat invasion by Mediterranean mussels Mytilus galloprovincialis. We studied sequences of the mitochondrial cytochrome oxidase subunit 1 (CO1) and the nuclear internal transcribed spacer (ITS1) of A. atra to determine patterns of differentiation among three localities on the South African coastline and the phylogenetic position of these populations relative to other populations of Aulacomya species in the Southern Hemisphere. Results from both mitochondrial and nuclear genes revealed a high level of diversity within South African populations from the west and south coast, with little to no geographic differentiation among these populations. Phylogenetic trees constructed using maximum likelihood and haplotype network analysis show that individuals from all three regions sampled are intermingled in groups with low bootstrap support. Our CO1 sequences exhibited a phylogeographic structure concordant with the spatial distribution in South Africa, Argentina, Chile and New Zealand. However, results for ITS1 showed a lack of differentiation over a large spatial scale stretching from South Africa to New Zealand. Future studies should include additional samples from across the species' distributional range and the examination expanded to include genetic markers with adaptive significance.

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