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Greg G Sass - One of the best experts on this subject based on the ideXlab platform.
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body condition wr and reproductive potential of bighead and Silver Carp hybrids postzygotic selection in the mississippi river basin
Ecology and Evolution, 2019Co-Authors: John M Epifanio, Michael A Mcclelland, James T. Lamer, Blake C Ruebush, Greg G SassAbstract:Invasive bighead (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix) are reproductively isolated in their native range, but form a bimodal, multigenerational hybrid swarm within the Mississippi River Basin (MRB). Despite observed F1 hybrid superiority in experimental settings, effects of postzygotic selection on bighead and Silver Carp hybrids have not been tested in a natural system. Individual parent and hybrid genotypes were resolved at 57 species-specific loci and used to evaluate postzygotic selection for body condition (Wr ) and female reproductive potential (presence of spawning stage gonads and gonadosomatic index [GSI]) in the MRB during 2009-2011. Body condition in the Marseilles Reach, Illinois River declined with a decrease in species-specific allele frequency from 1.0 to 0.4 for each species and early generation hybrids (F1, F2, and first-generation backcross) had lower mean Wr than late generation hybrids (2nd+ generation backcrosses) and parentals. Proportions of stage IV and stage V (spawning stage) female gonads differed between bighead and Silver Carp, but not among parentals and their early and late generation hybrids within the MRB. Mean GSI values did not differ between parentals and hybrids. Because reproductive potential did not differ between hybrids and parentals, our results suggest that early generation hybrids occur in low frequency either as a factor of poor condition (Wr ) and postreproductive survival, infrequent reproductive encounters by parental bighead and Silver Carp, or selection pressures acting on juvenile or immature life stages. Our results suggest that a combination of genetic and environmental factors may contribute to the postzygotic success of bighead and Silver Carp hybrids in the Mississippi River Basin.
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elements of concern in fillets of bighead and Silver Carp from the illinois river illinois
Chemosphere, 2014Co-Authors: Jeffrey M Levengood, Greg G Sass, David J Soucek, Amy Dickinson, John M EpifanioAbstract:Abstract Efforts to control invasive bighead ( Hypophthalmichthys nobilis ) and Silver Carp ( H . molitrix ) may include harvest for human consumption. We measured concentrations of arsenic (As), mercury (Hg), and selenium (Se) in fillets from Silver and bighead Carp collected from the lower Illinois River, Illinois, USA, to determine whether concentrations were of health concern and differed by species, size, and location. Concentrations of total As were below detection limits in most bighead (92%) and Silver (77%) Carp fillets, whereas inorganic As was below detection limits in all samples. Mean Hg concentrations were greater in bighead (0.068 mg kg −1 ) than in Silver Carp (0.035 mg kg −1 ), and were smallest in Carp from the confluence of the Illinois and Mississippi rivers. Mercury concentrations in fillets were positively correlated with body mass in both species. Concentrations of Hg were below the US Food and Drug Administration’s (USFDA) action level (1 ppm as methyl-Hg); however, concentrations in some bighead (70%) and Silver (12%) Carp fell within the range that would invoke a recommendation to limit meals in sensitive cohorts. Mean Se concentrations were greater in Silver (0.332 mg kg −1 ) than in bighead (0.281 mg kg −1 ) Carp fillets, and were below the 1.5 mg kg −1 limit for an unrestricted number of meals/month. The mean molar ratio of Se:Hg in fillets was lower in bighead (14.0) than in Silver (29.1) Carp and was negatively correlated with mass in both species Concentrations of Hg in bighead and Silver Carp fillets should be considered when assessing the risks associated with the use of these species as a protein source.
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Invasive bighead and Silver Carp effects on zooplankton communities in the Illinois River, Illinois, USA
Journal of Great Lakes Research, 2014Co-Authors: Greg G Sass, Collin Hinz, Anthony C. Erickson, Nerissa N. Mcclelland, Michael A Mcclelland, John M EpifanioAbstract:Aquatic invasive species introductions are a global environmental concern. Negative effects of invasive species are often manifested in alterations of food web structure and through competition with and predation upon native species. The Illinois River, Illinois, USA harbors invasive, planktivorous bighead, Hypophthalmichthys nobilis, and Silver Carp, Hypophthalmichthys molitrix, and can be a model ecosystem to test for their effects on zooplankton communities. We tested for bighead and Silver Carp effects on zooplankton communities pre- and post-establishment within one reach of the Illinois River and among river reaches that varied in abundances of these invasive fishes. The establishment of bighead and Silver Carp was associated with increased rotifer abundances, while cladoceran and copepod abundances were reduced relative to pre-establishment. Cladoceran and copepod abundance and biomass were negatively associated with bighead and Silver Carp abundances among reaches. Total zooplankton and rotifer abundance and biomass were positively associated with bighead and Silver Carp abundances. Our results suggest that bighead and Silver Carp have changed the zooplankton community of the Illinois River which may have implications for the food web, native species, and other ecosystems poised to be invaded, such as the Laurentian Great Lakes.
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a mark recapture population estimate for invasive Silver Carp hypophthalmichthys molitrix in the la grange reach illinois river
Biological Invasions, 2010Co-Authors: Greg G Sass, Nerissa N Michaels, Matthew T Ohara, Michael A Mcclelland, Kevin S Irons, Thad R Cook, Matthew R StroubAbstract:Invasive Silver Carp (Hypophthalmichthys molitrix) populations have expanded greatly in the Upper Mississippi River System (UMRS) since their introduction in the early 1970s. We conducted a Chapman-modified, continuous Schnabel mark-recapture population and biomass estimate for Silver Carp (106–901 mm) in the La Grange reach, Illinois River during 2007–2008. We estimated a total of 328,192 (95% CI 231,226–484,474) Silver Carp (2,544 per river km 1,792–3,756) comprising 705 (95% CI; 496–1,040) metric tons of biomass (5.5 metric tons per river km 3.8–8.1). Long Term Resource Monitoring Program (LTRMP) data from the La Grange reach showed an exponential increase in Silver Carp catches since 1998, with an intrinsic rate of increase approaching 84%. In 2008, Silver Carp comprised about 51% of the total LTRMP annual fish collection. To our knowledge, this large river reach may contain the greatest ambient densities of wild Silver Carp in the world. Our findings provide a target for reduction efforts and also emphasize the importance of the La Grange reach as a source population for potential expansion of the species to the Laurentian Great Lakes.
James T. Lamer - One of the best experts on this subject based on the ideXlab platform.
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body condition wr and reproductive potential of bighead and Silver Carp hybrids postzygotic selection in the mississippi river basin
Ecology and Evolution, 2019Co-Authors: John M Epifanio, Michael A Mcclelland, James T. Lamer, Blake C Ruebush, Greg G SassAbstract:Invasive bighead (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix) are reproductively isolated in their native range, but form a bimodal, multigenerational hybrid swarm within the Mississippi River Basin (MRB). Despite observed F1 hybrid superiority in experimental settings, effects of postzygotic selection on bighead and Silver Carp hybrids have not been tested in a natural system. Individual parent and hybrid genotypes were resolved at 57 species-specific loci and used to evaluate postzygotic selection for body condition (Wr ) and female reproductive potential (presence of spawning stage gonads and gonadosomatic index [GSI]) in the MRB during 2009-2011. Body condition in the Marseilles Reach, Illinois River declined with a decrease in species-specific allele frequency from 1.0 to 0.4 for each species and early generation hybrids (F1, F2, and first-generation backcross) had lower mean Wr than late generation hybrids (2nd+ generation backcrosses) and parentals. Proportions of stage IV and stage V (spawning stage) female gonads differed between bighead and Silver Carp, but not among parentals and their early and late generation hybrids within the MRB. Mean GSI values did not differ between parentals and hybrids. Because reproductive potential did not differ between hybrids and parentals, our results suggest that early generation hybrids occur in low frequency either as a factor of poor condition (Wr ) and postreproductive survival, infrequent reproductive encounters by parental bighead and Silver Carp, or selection pressures acting on juvenile or immature life stages. Our results suggest that a combination of genetic and environmental factors may contribute to the postzygotic success of bighead and Silver Carp hybrids in the Mississippi River Basin.
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using pharyngeal teeth and chewing pads to estimate juvenile Silver Carp total length in the la grange reach illinois river
North American Journal of Fisheries Management, 2017Co-Authors: Eli G. Lampo, Brent C. Knights, Jon M. Vallazza, Cory A. Anderson, Will T. Rechkemmer, Levi E. Solomon, Andrew F. Casper, Richard M. Pendleton, James T. LamerAbstract:AbstractThe Silver Carp Hypophthalmichthys molitrix is an invasive species in the Mississippi River basin; an understanding of their vulnerability to predation as juveniles may inform control by native predators and predator enhancement (e.g., stocking). Digestion of Silver Carp prey recovered from diets makes it difficult to determine the size-classes that are most vulnerable to predation by native fishes. The objective of this study was to determine whether the sizes of the chewing pad (CP), pharyngeal teeth (PT), and pharyngeal arch (PA)—the Silver Carp structures most often found intact in predator diets—were predictive of the TL of prey Silver Carp. During 2014 and 2015, juvenile Silver Carp (n = 136; <180 mm) were collected using 60-Hz pulsed-DC electrofishing and mini-fyke nets in the La Grange reach of the Illinois River. We extracted Silver Carp CPs (n = 136 fish) and PAs with PT intact (n = 129 fish) and measured CP length (CPL) and width (CPW), eight reproducible PT landmarks (PT1L–PT4L; PT1W–P...
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diagnostic snps reveal widespread introgressive hybridization between introduced bighead and Silver Carp in the mississippi river basin
Molecular Ecology, 2015Co-Authors: John M Epifanio, Michael A Mcclelland, James T. Lamer, Blake C Ruebush, Zarema H Arbieva, Greg G SassAbstract:Hybridization among conspecifics in native and introduced habitats has important implications for biological invasions in new ecosystems. Bighead (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix) are genetically isolated and occur in sympatry within their native range. Following their introduction to North America, however, introgressant hybrids have been reported throughout their expanded range within the Mississippi River Basin (MRB). The extent of introgression, both spatially and generationally, is largely unknown. Therefore, we examined mixed-species populations from across the MRB to characterize the extent of interspecific gene flow. We assayed 2798 individuals from nine locations with a suite of species-diagnostic SNPs (57 nuclear and one mitochondrial). Forty-four per cent (n = 1244) of individuals displayed hybrid genotypes. Moreover, the composition of hybrid genotypes varied among locations and represented complex hybrid swarms with multiple generations of gene flow. Introgressive hybrids were identified from all locations, were bidirectional and followed a bimodal distribution consisting primarily of parental or parental-like genotypes and phenotypes. All described hybrid categories were present among individuals from 1999 to 2008, with parents and later-generation backcrosses representing the largest proportion of individuals among years. Our mitochondrial SNP (COII), tested on a subset of 730 individuals, revealed a Silver Carp maternal bias in 13 of 21 (62%) F1 hybrids, in all Silver Carp backcrosses, and maintained throughout many of the bighead Carp backcrosses. The application of this suite of diagnostic markers and the spatial coverage permits a deeper examination of the complexity in hybrid swarms between two invasive, introduced species.
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introgressive hybridization between bighead Carp and Silver Carp in the mississippi and illinois rivers
North American Journal of Fisheries Management, 2010Co-Authors: Chad R Dolan, James T. Lamer, Jessica L Petersen, John H Chick, John M EpifanioAbstract:Abstract Asian Carps are classified as either bighead Carp Hypophthalmichthys nobilis or Silver Carp H. molitrix by multiple presumptively diagnostic morphological characteristics; however, hybrids pose a dilemma. Fish sharing the morphological characteristics of both species were observed in an Illinois River backwater (Calhoun County, Illinois) approximately 5 mi (8 km) upriver from the confluence with the Mississippi River as well as in two locations in Pool 26 of the Mississippi River (Madison County, Illinois). Biopsied tissues from individuals exhibiting mixed morphological features were analyzed at four diagnostic allozyme loci (ADH-1*, sMDH-A*, CK-A*, and sSOD-1*) via starch gel electrophoresis. This comparison revealed a high percentage of hybridization (22.5%) from an indiscriminate sample of 120 fish. Moreover, an unexpected percentage (12.5%) of individuals identified in the wild as either parental bighead Carp or Silver Carp by gill raker morphology were genetically identified as hybrids. Fin...
Wenshui Xia - One of the best experts on this subject based on the ideXlab platform.
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impact of wall material on the physiochemical properties and oxidative stability of microencapsulated spray dried Silver Carp oil
Journal of Aquatic Food Product Technology, 2019Co-Authors: Tazbidul Nawas, Shofiul Azam, Abuubakar Hassan Ramadhan, Wenshui XiaAbstract:This study aimed to microencapsulate Silver Carp oil by spray drying with different combinations of wall materials (gum Arabic, modified starch Hi-cap, maltodextrin, and inulin) and evaluate the ef...
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aggregation and structural changes of Silver Carp actomyosin as affected by mild acidification with d gluconic acid δ lactone
Food Chemistry, 2012Co-Authors: Wenshui Xia, Qixing JiangAbstract:The structural changes and aggregation properties of Silver Carp actomyosin acidified with d-gluconic acid-δ-lactone (GDL) were investigated. Results showed that Silver Carp actomyosin underwent aggregation and formation of precipitate as indicated by turbidity and centrifugation coupled electrophoresis analysis. Circular dichroism indicated that myosin rod unfolded during acidification, resulting in a gradual decrease in α-helical content. The changes in tertiary structure of actomyosin under acidic conditions were demonstrated by second-derivative UV spectra and intrinsic fluorescence. Tyrosine residues were exposed to the surface of proteins when pH was decreased to 5.5, and were buried inside the protein aggregates with further reduction in pH. In contrast, more tryptophan residues were exposed to the polar environment with decreasing pH. 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide crosslinking experiments showed that the intensity of myosin heavy chain (MHC) bands decreased sharply with decreasing pH and the actin bands decreased more slowly, suggesting that MHC is the major protein component involved in the non-covalent cross-linking and formation of aggregates during acidification of Silver Carp actomyosin.
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effect of fermentation temperature on the microbial and physicochemical properties of Silver Carp sausages inoculated with pediococcus pentosaceus
Food Chemistry, 2010Co-Authors: Wenshui Xia, Fang Yang, Jin Moon Kim, Xiaohua NieAbstract:Abstract The effect of fermentation with Pediococcus pentosaceus at different temperatures ranging from 15 to 37 °C on the quality characteristics of Silver Carp sausages was investigated. Higher temperature stimulated the rapid growth of lactic acid bacteria, resulting in a rapid decline in pH, and consequently suppressed the growth of Pseudomonas, Micrococcaceae and Enterobacteriaceae. However, increasing fermentation temperature gave a progressive increase in total volatile basic nitrogen and biogenic amines in fermented Silver Carp sausages. Histamine was the main biogenic amine, exceeding 100 mg/kg after 48 h of fermentation at temperatures above 30 °C. Higher content of non-protein nitrogen and α-amino nitrogen correlated with the electrophoretic studies, which showed that proteolysis of high molecular weight myofibrillar and sarcoplasmic proteins was more prominent at higher fermentation temperatures. Products fermented at 23–30 °C showed greatest consumer preference and most favourable textural properties.
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characterization of fermented Silver Carp sausages inoculated with mixed starter culture
Lwt - Food Science and Technology, 2008Co-Authors: Wenshui XiaAbstract:To improve the characteristics and functionality, and increase the use of fish muscle, three groups mixed starter cultures (group one: Lactobacillus plantarum-15, Staphylococcus xylosus-12 and Pediococcus pentosaceus-ATCC33316 [S-PXP]; group two: Lactobacillus planatrum-15, Staphylococcus xylosus-12 and Lactobacillus casei subs casei-1.001 [S-PXC]; and group three: Staphylococcus xylosus-12, Lactobacillus casei subsp. casei-1.001 and P. pentosaceus-ATCC33316 [S-XCP]) were inoculated in minced Silver Carp muscle to produce a fermented fish product. During the 48 h fermentation at 30 °C, Silver Carp muscle inoculated with mixed starter cultures resulted in a rapid pH decrease, suppression in the increase of thiobarturic acid (TBARS) values, total volatile base nitrogen (TVB-N), trimethylamine (TMA), and the growth of spoilage bacteria and pathogens, and had higher whiteness than the control (without any starter) (P<0.05). The changes in SDS-PAGE indicated extensive hydrolysis of muscle protein occurred during fermentation. This study showed that the mixed starter cultures could substantially improve the flavor, digestibility, and nutritional value of the Silver Carp muscle.
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effect of mixed starter cultures fermentation on the characteristics of Silver Carp sausages
World Journal of Microbiology & Biotechnology, 2007Co-Authors: Wenshui XiaAbstract:To improve the quality and functionality and increase the utilization of Silver Carp (Hypophthalmichthys molitrix) muscle, three groups of Silver Carp sausages inoculated with the combinations of Staphylococcus xylosus-12 with Lactobacillus plantarum-15, Pediococcus pentosaceus-ATCC33316, and Lactobacillus casei subsp. casei-1.001, and a batch without any starter (control) were prepared. During the 48 h fermentation at 30°C, Silver Carp sausages inoculated with mixed starter cultures resulted in a rapid pH decrease, suppression in the growth of Enterobacteriaceae, Pseudomonas, yeasts and molds, and exhibited higher texture profiles (hardness, gumminess, springiness, and chewiness) and whiteness than the control (P < 0.05). The changes in non-protein nitrogen (NPN), free amino acid and SDS-PAGE indicated severe hydrolysis of muscle protein occurred during fermentation. Polyunsaturated fatty acids were higher in quantity in sausages with cultures compare to the control. No significant differences for taste, texture, and appearance were found among batches with mixed starters. The sausage inoculated with the combination of Lactobacillus plantarum-15, S. xylosus-12, and Lactobacillus casei subsp. casei-1.001 (S-PXC) gained highest scores for flavor and overall acceptability. There was an apparent positive correlation (r = 0.87) between the NPN and the overall acceptability in sausages, whereas pH value showed a significantly negative correlations (r = –0.89 to −0.99, P < 0.05) with taste, flavor, texture, appearance, and overall acceptability.
Michael A Mcclelland - One of the best experts on this subject based on the ideXlab platform.
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body condition wr and reproductive potential of bighead and Silver Carp hybrids postzygotic selection in the mississippi river basin
Ecology and Evolution, 2019Co-Authors: John M Epifanio, Michael A Mcclelland, James T. Lamer, Blake C Ruebush, Greg G SassAbstract:Invasive bighead (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix) are reproductively isolated in their native range, but form a bimodal, multigenerational hybrid swarm within the Mississippi River Basin (MRB). Despite observed F1 hybrid superiority in experimental settings, effects of postzygotic selection on bighead and Silver Carp hybrids have not been tested in a natural system. Individual parent and hybrid genotypes were resolved at 57 species-specific loci and used to evaluate postzygotic selection for body condition (Wr ) and female reproductive potential (presence of spawning stage gonads and gonadosomatic index [GSI]) in the MRB during 2009-2011. Body condition in the Marseilles Reach, Illinois River declined with a decrease in species-specific allele frequency from 1.0 to 0.4 for each species and early generation hybrids (F1, F2, and first-generation backcross) had lower mean Wr than late generation hybrids (2nd+ generation backcrosses) and parentals. Proportions of stage IV and stage V (spawning stage) female gonads differed between bighead and Silver Carp, but not among parentals and their early and late generation hybrids within the MRB. Mean GSI values did not differ between parentals and hybrids. Because reproductive potential did not differ between hybrids and parentals, our results suggest that early generation hybrids occur in low frequency either as a factor of poor condition (Wr ) and postreproductive survival, infrequent reproductive encounters by parental bighead and Silver Carp, or selection pressures acting on juvenile or immature life stages. Our results suggest that a combination of genetic and environmental factors may contribute to the postzygotic success of bighead and Silver Carp hybrids in the Mississippi River Basin.
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diagnostic snps reveal widespread introgressive hybridization between introduced bighead and Silver Carp in the mississippi river basin
Molecular Ecology, 2015Co-Authors: John M Epifanio, Michael A Mcclelland, James T. Lamer, Blake C Ruebush, Zarema H Arbieva, Greg G SassAbstract:Hybridization among conspecifics in native and introduced habitats has important implications for biological invasions in new ecosystems. Bighead (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix) are genetically isolated and occur in sympatry within their native range. Following their introduction to North America, however, introgressant hybrids have been reported throughout their expanded range within the Mississippi River Basin (MRB). The extent of introgression, both spatially and generationally, is largely unknown. Therefore, we examined mixed-species populations from across the MRB to characterize the extent of interspecific gene flow. We assayed 2798 individuals from nine locations with a suite of species-diagnostic SNPs (57 nuclear and one mitochondrial). Forty-four per cent (n = 1244) of individuals displayed hybrid genotypes. Moreover, the composition of hybrid genotypes varied among locations and represented complex hybrid swarms with multiple generations of gene flow. Introgressive hybrids were identified from all locations, were bidirectional and followed a bimodal distribution consisting primarily of parental or parental-like genotypes and phenotypes. All described hybrid categories were present among individuals from 1999 to 2008, with parents and later-generation backcrosses representing the largest proportion of individuals among years. Our mitochondrial SNP (COII), tested on a subset of 730 individuals, revealed a Silver Carp maternal bias in 13 of 21 (62%) F1 hybrids, in all Silver Carp backcrosses, and maintained throughout many of the bighead Carp backcrosses. The application of this suite of diagnostic markers and the spatial coverage permits a deeper examination of the complexity in hybrid swarms between two invasive, introduced species.
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Invasive bighead and Silver Carp effects on zooplankton communities in the Illinois River, Illinois, USA
Journal of Great Lakes Research, 2014Co-Authors: Greg G Sass, Collin Hinz, Anthony C. Erickson, Nerissa N. Mcclelland, Michael A Mcclelland, John M EpifanioAbstract:Aquatic invasive species introductions are a global environmental concern. Negative effects of invasive species are often manifested in alterations of food web structure and through competition with and predation upon native species. The Illinois River, Illinois, USA harbors invasive, planktivorous bighead, Hypophthalmichthys nobilis, and Silver Carp, Hypophthalmichthys molitrix, and can be a model ecosystem to test for their effects on zooplankton communities. We tested for bighead and Silver Carp effects on zooplankton communities pre- and post-establishment within one reach of the Illinois River and among river reaches that varied in abundances of these invasive fishes. The establishment of bighead and Silver Carp was associated with increased rotifer abundances, while cladoceran and copepod abundances were reduced relative to pre-establishment. Cladoceran and copepod abundance and biomass were negatively associated with bighead and Silver Carp abundances among reaches. Total zooplankton and rotifer abundance and biomass were positively associated with bighead and Silver Carp abundances. Our results suggest that bighead and Silver Carp have changed the zooplankton community of the Illinois River which may have implications for the food web, native species, and other ecosystems poised to be invaded, such as the Laurentian Great Lakes.
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a mark recapture population estimate for invasive Silver Carp hypophthalmichthys molitrix in the la grange reach illinois river
Biological Invasions, 2010Co-Authors: Greg G Sass, Nerissa N Michaels, Matthew T Ohara, Michael A Mcclelland, Kevin S Irons, Thad R Cook, Matthew R StroubAbstract:Invasive Silver Carp (Hypophthalmichthys molitrix) populations have expanded greatly in the Upper Mississippi River System (UMRS) since their introduction in the early 1970s. We conducted a Chapman-modified, continuous Schnabel mark-recapture population and biomass estimate for Silver Carp (106–901 mm) in the La Grange reach, Illinois River during 2007–2008. We estimated a total of 328,192 (95% CI 231,226–484,474) Silver Carp (2,544 per river km 1,792–3,756) comprising 705 (95% CI; 496–1,040) metric tons of biomass (5.5 metric tons per river km 3.8–8.1). Long Term Resource Monitoring Program (LTRMP) data from the La Grange reach showed an exponential increase in Silver Carp catches since 1998, with an intrinsic rate of increase approaching 84%. In 2008, Silver Carp comprised about 51% of the total LTRMP annual fish collection. To our knowledge, this large river reach may contain the greatest ambient densities of wild Silver Carp in the world. Our findings provide a target for reduction efforts and also emphasize the importance of the La Grange reach as a source population for potential expansion of the species to the Laurentian Great Lakes.
John M Epifanio - One of the best experts on this subject based on the ideXlab platform.
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body condition wr and reproductive potential of bighead and Silver Carp hybrids postzygotic selection in the mississippi river basin
Ecology and Evolution, 2019Co-Authors: John M Epifanio, Michael A Mcclelland, James T. Lamer, Blake C Ruebush, Greg G SassAbstract:Invasive bighead (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix) are reproductively isolated in their native range, but form a bimodal, multigenerational hybrid swarm within the Mississippi River Basin (MRB). Despite observed F1 hybrid superiority in experimental settings, effects of postzygotic selection on bighead and Silver Carp hybrids have not been tested in a natural system. Individual parent and hybrid genotypes were resolved at 57 species-specific loci and used to evaluate postzygotic selection for body condition (Wr ) and female reproductive potential (presence of spawning stage gonads and gonadosomatic index [GSI]) in the MRB during 2009-2011. Body condition in the Marseilles Reach, Illinois River declined with a decrease in species-specific allele frequency from 1.0 to 0.4 for each species and early generation hybrids (F1, F2, and first-generation backcross) had lower mean Wr than late generation hybrids (2nd+ generation backcrosses) and parentals. Proportions of stage IV and stage V (spawning stage) female gonads differed between bighead and Silver Carp, but not among parentals and their early and late generation hybrids within the MRB. Mean GSI values did not differ between parentals and hybrids. Because reproductive potential did not differ between hybrids and parentals, our results suggest that early generation hybrids occur in low frequency either as a factor of poor condition (Wr ) and postreproductive survival, infrequent reproductive encounters by parental bighead and Silver Carp, or selection pressures acting on juvenile or immature life stages. Our results suggest that a combination of genetic and environmental factors may contribute to the postzygotic success of bighead and Silver Carp hybrids in the Mississippi River Basin.
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diagnostic snps reveal widespread introgressive hybridization between introduced bighead and Silver Carp in the mississippi river basin
Molecular Ecology, 2015Co-Authors: John M Epifanio, Michael A Mcclelland, James T. Lamer, Blake C Ruebush, Zarema H Arbieva, Greg G SassAbstract:Hybridization among conspecifics in native and introduced habitats has important implications for biological invasions in new ecosystems. Bighead (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix) are genetically isolated and occur in sympatry within their native range. Following their introduction to North America, however, introgressant hybrids have been reported throughout their expanded range within the Mississippi River Basin (MRB). The extent of introgression, both spatially and generationally, is largely unknown. Therefore, we examined mixed-species populations from across the MRB to characterize the extent of interspecific gene flow. We assayed 2798 individuals from nine locations with a suite of species-diagnostic SNPs (57 nuclear and one mitochondrial). Forty-four per cent (n = 1244) of individuals displayed hybrid genotypes. Moreover, the composition of hybrid genotypes varied among locations and represented complex hybrid swarms with multiple generations of gene flow. Introgressive hybrids were identified from all locations, were bidirectional and followed a bimodal distribution consisting primarily of parental or parental-like genotypes and phenotypes. All described hybrid categories were present among individuals from 1999 to 2008, with parents and later-generation backcrosses representing the largest proportion of individuals among years. Our mitochondrial SNP (COII), tested on a subset of 730 individuals, revealed a Silver Carp maternal bias in 13 of 21 (62%) F1 hybrids, in all Silver Carp backcrosses, and maintained throughout many of the bighead Carp backcrosses. The application of this suite of diagnostic markers and the spatial coverage permits a deeper examination of the complexity in hybrid swarms between two invasive, introduced species.
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elements of concern in fillets of bighead and Silver Carp from the illinois river illinois
Chemosphere, 2014Co-Authors: Jeffrey M Levengood, Greg G Sass, David J Soucek, Amy Dickinson, John M EpifanioAbstract:Abstract Efforts to control invasive bighead ( Hypophthalmichthys nobilis ) and Silver Carp ( H . molitrix ) may include harvest for human consumption. We measured concentrations of arsenic (As), mercury (Hg), and selenium (Se) in fillets from Silver and bighead Carp collected from the lower Illinois River, Illinois, USA, to determine whether concentrations were of health concern and differed by species, size, and location. Concentrations of total As were below detection limits in most bighead (92%) and Silver (77%) Carp fillets, whereas inorganic As was below detection limits in all samples. Mean Hg concentrations were greater in bighead (0.068 mg kg −1 ) than in Silver Carp (0.035 mg kg −1 ), and were smallest in Carp from the confluence of the Illinois and Mississippi rivers. Mercury concentrations in fillets were positively correlated with body mass in both species. Concentrations of Hg were below the US Food and Drug Administration’s (USFDA) action level (1 ppm as methyl-Hg); however, concentrations in some bighead (70%) and Silver (12%) Carp fell within the range that would invoke a recommendation to limit meals in sensitive cohorts. Mean Se concentrations were greater in Silver (0.332 mg kg −1 ) than in bighead (0.281 mg kg −1 ) Carp fillets, and were below the 1.5 mg kg −1 limit for an unrestricted number of meals/month. The mean molar ratio of Se:Hg in fillets was lower in bighead (14.0) than in Silver (29.1) Carp and was negatively correlated with mass in both species Concentrations of Hg in bighead and Silver Carp fillets should be considered when assessing the risks associated with the use of these species as a protein source.
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Invasive bighead and Silver Carp effects on zooplankton communities in the Illinois River, Illinois, USA
Journal of Great Lakes Research, 2014Co-Authors: Greg G Sass, Collin Hinz, Anthony C. Erickson, Nerissa N. Mcclelland, Michael A Mcclelland, John M EpifanioAbstract:Aquatic invasive species introductions are a global environmental concern. Negative effects of invasive species are often manifested in alterations of food web structure and through competition with and predation upon native species. The Illinois River, Illinois, USA harbors invasive, planktivorous bighead, Hypophthalmichthys nobilis, and Silver Carp, Hypophthalmichthys molitrix, and can be a model ecosystem to test for their effects on zooplankton communities. We tested for bighead and Silver Carp effects on zooplankton communities pre- and post-establishment within one reach of the Illinois River and among river reaches that varied in abundances of these invasive fishes. The establishment of bighead and Silver Carp was associated with increased rotifer abundances, while cladoceran and copepod abundances were reduced relative to pre-establishment. Cladoceran and copepod abundance and biomass were negatively associated with bighead and Silver Carp abundances among reaches. Total zooplankton and rotifer abundance and biomass were positively associated with bighead and Silver Carp abundances. Our results suggest that bighead and Silver Carp have changed the zooplankton community of the Illinois River which may have implications for the food web, native species, and other ecosystems poised to be invaded, such as the Laurentian Great Lakes.
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introgressive hybridization between bighead Carp and Silver Carp in the mississippi and illinois rivers
North American Journal of Fisheries Management, 2010Co-Authors: Chad R Dolan, James T. Lamer, Jessica L Petersen, John H Chick, John M EpifanioAbstract:Abstract Asian Carps are classified as either bighead Carp Hypophthalmichthys nobilis or Silver Carp H. molitrix by multiple presumptively diagnostic morphological characteristics; however, hybrids pose a dilemma. Fish sharing the morphological characteristics of both species were observed in an Illinois River backwater (Calhoun County, Illinois) approximately 5 mi (8 km) upriver from the confluence with the Mississippi River as well as in two locations in Pool 26 of the Mississippi River (Madison County, Illinois). Biopsied tissues from individuals exhibiting mixed morphological features were analyzed at four diagnostic allozyme loci (ADH-1*, sMDH-A*, CK-A*, and sSOD-1*) via starch gel electrophoresis. This comparison revealed a high percentage of hybridization (22.5%) from an indiscriminate sample of 120 fish. Moreover, an unexpected percentage (12.5%) of individuals identified in the wild as either parental bighead Carp or Silver Carp by gill raker morphology were genetically identified as hybrids. Fin...
