The Experts below are selected from a list of 3702 Experts worldwide ranked by ideXlab platform
Russell D Vetter - One of the best experts on this subject based on the ideXlab platform.
-
population genetic structure in the redefined vermilion rockfish Sebastes miniatus indicates limited larval dispersal and reveals natural management units
Canadian Journal of Fisheries and Aquatic Sciences, 2009Co-Authors: Russell D Vetter, J R HydeAbstract:Recent studies have revealed that the vermilion rockfish Sebastes miniatus is a cryptic species pair. The splitting of this species impacts stock size estimates and draws attention to the unintende...
-
cryptic speciation in the vermilion rockfish Sebastes miniatus and the role of bathymetry in the speciation process
Molecular Ecology, 2008Co-Authors: J R Hyde, Eric A Lynn, Carol Kimbrell, J E Budrick, Russell D VetterAbstract:: A recent phylogenetic review of the genus Sebastes suggested the existence of a cryptic species of vermilion rockfish (Sebastes miniatus). To evaluate the geographical and bathymetric range of the Type 1 and Type 2 forms reported in that study, cytochrome b sequences were examined from 548 fish. Type 1 fish were found primarily south of Point Conception on reefs deeper than 100 m. Type 2 fish were common range-wide at sites shallower than 100 m. Reproductive isolation between the two types was tested using nine microsatellite loci. Estimates of genetic divergence were made using the fixation index (F(ST)) and correspondence between haplotype and genotype was tested by Bayesian population assignment and multivariate plotting of individual genotypes. Microsatellite analyses gave strong support for the presence of two distinct groups of genotypes. All fish with Type 1 haplotypes and fish with Type 2 haplotypes from 100 m depth assigned strongly to the Type 1 genotype group. Morphometric comparisons between the two genotypic groups revealed significant differences at three of the six examined measurements. Differences in both genetics, depth of occurrence, and morphology suggest these are separate species. This observation along with evidence of depth segregation in many recent species pairs led us to hypothesize a speciation model for Sebastes spp. by which the loss or truncation of a depth-related ontogenetic migration can lead to the creation of reproductively isolated populations.
-
the origin evolution and diversification of rockfishes of the genus Sebastes cuvier
Molecular Phylogenetics and Evolution, 2007Co-Authors: John R Hyde, Russell D VetterAbstract:The evolutionary relationships of the livebearing rockfishes of the genus Sebastes have been a point of interest since their original description. With over 65 species found in the northeast Pacific (NEP), 27 in the northwest Pacific (NWP), seven in the Gulf of California (GC), four in the north Atlantic (NA) and at least two in the southern hemisphere (SH), they represent a fascinating lineage for studies of spatial and temporal patterns of dispersal, vicariance and speciation in the marine environment. Previous studies of Sebastes species have attempted to reconstruct their phylogeny using allozyme patterns or portions of a single mitochondrial gene while incompletely sampling the genus, resulting in a partial picture with low statistical support. In this study, genetic analyses using sequence data (5581 characters) from seven mitochondrial genes (cytochrome b, cytochrome c oxidase subunit 1, 12S rRNA, 16S rRNA, tRNA proline, tRNA threonine and the control region) and two nuclear genes (recombination activating gene 2 and internal transcribed spacer 1), along with a near complete sampling of species, have produced a well supported phylogenetic hypothesis of the relationships between Sebastes species as well as clarifying their position within the scorpaenid subfamily, Sebastinae. Though studies of similar magnitude have been conducted at the family and subfamily level, this represents the most detailed and extensive examination of biogeography and marine speciation within a single, widely distributed marine fish genus. Both Bayesian posterior and maximum parsimony analyses produced highly similar phylogenies suggesting an origin for Sebastes at high-latitudes in the NWP. The majority of previously proposed sub-generic groupings based upon morphology are found to be either para- or polyphletic. Using Bayesian-derived genetic distance measures together with rate smoothing techniques, a molecular clock was applied to the phylogeny. The clock-calibrated data suggest that Sebastes originated in the middle Miocene, concordant with fossil data, and began substantial diversification and dispersal in synchrony with high-latitude cooling and establishment of productive upwelling systems across the north Pacific (NP) in the late Miocene. Contrary to contemporary taxonomic criteria that often group Asian and North American species based on common morphology, the molecular phylogenies tend to indicate geographically circumscribed lineages with no evidence for repeated long distance dispersal between disjunct biogeographic provinces (e.g., Asian species nested within a North American lineage). No examples of large-scale glacial vicariance as would be suggested by Asian and North American sibling species were observed. To the contrary, sibling species tended to be in geographic proximity. While occasional long distance dispersal may occur, such as the single colonization of the SH, and thermal barriers presently exist between the NP, NA, GC, and SH taxa, the observable patterns in Sebastes suggest colonization occurs by stepwise invasion of newly available habitat when temperature conditions permit. Colonization events are spread throughout the sub-generic lineages. Vicariant isolation processes may occur on smaller geographic scales perhaps due to local isolating mechanisms such as glacial advance and retreat, sea level change, and ocean currents. Allopatric differences may be enhanced by a tendency for female mate choice and assortative mating in these livebearing species. The ongoing process of thermal advance and retreat is reflected in contemporary patterns of phylogeographic population genetic structure within species and may be enhanced under climate warming.
-
population structure of copper rockfish Sebastes caurinus reflects postglacial colonization and contemporary patterns of larval dispersal
Canadian Journal of Fisheries and Aquatic Sciences, 2002Co-Authors: Vincent P. Buonaccorsi, Carol Kimbrell, Eric A Lynn, Russell D VetterAbstract:The copper rockfish (Sebastes caurinus) is a benthic, nonmigratory, rocky reef species with pelagic larval and juvenile stages lasting several months. Adults are commonly distributed in temperate c...
-
cryptic species of rockfishes Sebastes scorpaenidae in the southern hemisphere inferred from mitochondrial lineages
Journal of Heredity, 1999Co-Authors: Axayacatl Rochaolivares, Richard H Rosenblatt, Russell D VetterAbstract:We used mitochondrial DNA sequence variation of Sebastes from the southeastern Pacific and three localities in the South Atlantic to address long-standing systematic and evolutionary issues regarding the number of species in the Southern Hemisphere. Sequences of the hypervariable mitochondrial control region were obtained from 10 specimens of S. capensis from South Africa (n = 5) and from Tristan da Cunha Island (n = 5) and 27 of S. oculatus from Valparaiso, Chile (n = 10), and the Falkland Islands (n = 17). Results of the study include (1) significant levels of genetic differentiation among the sampled populations (phi ST = 0.225, P < .000001), thus indicating limited gene flow; (2) corroboration of the existence of two different lineages of austral Sebastes corresponding to S. capensis and S. oculatus; (3) finding that S. capensis is not restricted to Tristan da Cunha and South Africa, but is widespread across the South Atlantic; (4) the position of S. capensis as the ancestral lineage of the austral Sebastes; (5) the existence of a third evolutionary lineage with high levels of genetic divergence, particularly abundant in the south-western Atlantic, which may be recognized as a third austral species of Sebastes.
J R Hyde - One of the best experts on this subject based on the ideXlab platform.
-
population genetic structure in the redefined vermilion rockfish Sebastes miniatus indicates limited larval dispersal and reveals natural management units
Canadian Journal of Fisheries and Aquatic Sciences, 2009Co-Authors: Russell D Vetter, J R HydeAbstract:Recent studies have revealed that the vermilion rockfish Sebastes miniatus is a cryptic species pair. The splitting of this species impacts stock size estimates and draws attention to the unintende...
-
cryptic speciation in the vermilion rockfish Sebastes miniatus and the role of bathymetry in the speciation process
Molecular Ecology, 2008Co-Authors: J R Hyde, Eric A Lynn, Carol Kimbrell, J E Budrick, Russell D VetterAbstract:: A recent phylogenetic review of the genus Sebastes suggested the existence of a cryptic species of vermilion rockfish (Sebastes miniatus). To evaluate the geographical and bathymetric range of the Type 1 and Type 2 forms reported in that study, cytochrome b sequences were examined from 548 fish. Type 1 fish were found primarily south of Point Conception on reefs deeper than 100 m. Type 2 fish were common range-wide at sites shallower than 100 m. Reproductive isolation between the two types was tested using nine microsatellite loci. Estimates of genetic divergence were made using the fixation index (F(ST)) and correspondence between haplotype and genotype was tested by Bayesian population assignment and multivariate plotting of individual genotypes. Microsatellite analyses gave strong support for the presence of two distinct groups of genotypes. All fish with Type 1 haplotypes and fish with Type 2 haplotypes from 100 m depth assigned strongly to the Type 1 genotype group. Morphometric comparisons between the two genotypic groups revealed significant differences at three of the six examined measurements. Differences in both genetics, depth of occurrence, and morphology suggest these are separate species. This observation along with evidence of depth segregation in many recent species pairs led us to hypothesize a speciation model for Sebastes spp. by which the loss or truncation of a depth-related ontogenetic migration can lead to the creation of reproductively isolated populations.
Sanden Monica - One of the best experts on this subject based on the ideXlab platform.
-
Fremmedstoffer i snabeluer (Sebastes mentella) og vanlig uer (Sebastes norvegicus) - Sluttrapport for kartleggingsprogrammet «Miljøgifter i fisk og fiskevarer» 2016-2018
Havforskningsinstituttet, 2020Co-Authors: Nilsen, Bente Merete, Frantzen Sylvia, Sanden MonicaAbstract:I dette arbeidet er det gjennomført en omfattende kartlegging av viktige fremmedstoffer i snabeluer (Sebastes mentella) og vanlig uer (Sebastes norvegicus) fra norske farvann. Konsentrasjonene av tungmetaller og organiske miljøgifter i filet av 522 snabeluer og 223 vanlig uer var generelt lave. Nivåene var noe lavere i vanlig uer enn i snabeluer, og i begge arter var nivåene betydelig lavere enn grenseverdiene som gjelder for kvikksølv, kadmium, bly, sum dioksiner, sum dioksiner og dioksinlignende PCB og sum ikke-dioksinlignende PCB (PCB6) i fiskefilet til humant konsum i Norge og EU. Konsentrasjonene i lever var høyere enn i filet, og nivået av kadmium i lever av snabeluer var uvanlig høyt i forhold til nivåene i lever av andre fiskearter fra norske farvann. Én enkelt samleprøve av lever fra snabeluer hadde et innhold av dioksiner og dioksinlignende PCB over grenseverdien for humant konsum. Konsentrasjonene av fremmedstoffer varierte mellom de ulike områdene der fisken var fanget, og variasjonsmønsteret mellom områdene var svært likt for de fleste av fremmedstoffene. For vanlig uer var det en tydelig nord-sør gradient i nivåene med høyest nivåer i de sørligste områdene, men for snabeluer var det ingen tydelig geografisk trend. Funnene i denne undersøkelsen har vist at selv om snabeluer og vanlig uer er arter som vokser sent og lever lenge, er nivåene av fremmedstoffer i filet av disse artene lave.publishedVersio
-
Fremmedstoffer i snabeluer (Sebastes mentella) og vanlig uer (Sebastes norvegicus) - Sluttrapport for kartleggingsprogrammet «Miljøgifter i fisk og fiskevarer» 2016-2018
Havforskningsinstituttet, 2020Co-Authors: Nilsen, Bente Merete, Frantzen Sylvia, Sanden MonicaAbstract:I dette arbeidet er det gjennomført en omfattende kartlegging av viktige fremmedstoffer i snabeluer (Sebastes mentella) og vanlig uer (Sebastes norvegicus) fra norske farvann. Konsentrasjonene av tungmetaller og organiske miljøgifter i filet av 522 snabeluer og 223 vanlig uer var generelt lave. Nivåene var noe lavere i vanlig uer enn i snabeluer, og i begge arter var nivåene betydelig lavere enn grenseverdiene som gjelder for kvikksølv, kadmium, bly, sum dioksiner, sum dioksiner og dioksinlignende PCB og sum ikke-dioksinlignende PCB (PCB6) i fiskefilet til humant konsum i Norge og EU. Konsentrasjonene i lever var høyere enn i filet, og nivået av kadmium i lever av snabeluer var uvanlig høyt i forhold til nivåene i lever av andre fiskearter fra norske farvann. Én enkelt samleprøve av lever fra snabeluer hadde et innhold av dioksiner og dioksinlignende PCB over grenseverdien for humant konsum. Konsentrasjonene av fremmedstoffer varierte mellom de ulike områdene der fisken var fanget, og variasjonsmønsteret mellom områdene var svært likt for de fleste av fremmedstoffene. For vanlig uer var det en tydelig nord-sør gradient i nivåene med høyest nivåer i de sørligste områdene, men for snabeluer var det ingen tydelig geografisk trend. Funnene i denne undersøkelsen har vist at selv om snabeluer og vanlig uer er arter som vokser sent og lever lenge, er nivåene av fremmedstoffer i filet av disse artene lave
Christophe Pampoulie - One of the best experts on this subject based on the ideXlab platform.
-
population structure of beaked redfish Sebastes mentella evidence of divergence associated with different habitats
Ices Journal of Marine Science, 2010Co-Authors: Steven X Cadrin, Matthias Bernreuther, Anna Kristin Danielsdottir, Einar Hjorleifsson, Torild Johansen, Lisa A Kerr, Kristjan Kristinsson, Stefano Mariani, Kjell Harald Nedreaas, Christophe PampoulieAbstract:Cadrin, S. X., Bernreuther, M., Danielsdottir, A. K., Hjorleifsson, E., Johansen, T., Kerr, L., Kristinsson, K., Mariani, S., Nedreaas, K., Pampoulie, C., Planque, B., Reinert, J., Saborido-Rey, F., Sigurðsson, T., and Stransky, C. 2010. Population structure of beaked redfish, Sebastes mentella: evidence of divergence associated with different habitats. - ICES Journal of Marine Science, 67: 1617-1630.Throughout their range, Sebastes spp. are adapted to a diversity of ecological niches, with overlapping spatial distributions of different species that have little or no morphological differences. Divergence of behavioural groups into depth-defined adult habitats has led to reproductive isolation, adaptive radiation, and speciation in the genus Sebastes. Recent genetic research, supported by life-history information, indicates four biological stocks of Sebastes mentella in the Irminger Sea and adjacent waters: a western stock, a deep-pelagic stock, a shallow-pelagic stock, and an Iceland slope stock. Congruent differences in fatty acids and parasites suggest that these genetically distinct populations are adapted to disparate trophic habitats in pelagic waters (shallower and deeper than the deep-scattering layer) and in demersal habitats on the continental slope. Morphology of pelagic forms is also more streamlined than demersal forms. Although genetic differences and evidence for reproductive isolation are clear, these populations appear to share common nursery habitats on the Greenland shelf. We propose a redefinition of practical management units near the Irminger Sea based on geographic proxies for biological stocks and minimizing mixed-stock catches according to the spatial patterns of the recent fishery.
-
resolving species identification problems in the genus Sebastes using nuclear genetic markers
Fisheries Research, 2008Co-Authors: Christophe Pampoulie, Anna Kristin DanielsdottirAbstract:Abstract The identification of North Atlantic redfish has been controversial and remains a difficult task due to overlapping of meristic and morphological characters. Here we used nine microsatellite loci to assess the level of genetic differentiation among these species and assess the resolution power of these microsatellite loci for individual assignment-based analyses. Conventional analyses as well as individual Bayesian assignment methods clearly separated the four species of North Atlantic redfish as well as the giant form of Sebastes marinus and the so-called “oceanic” and “deep-sea” types of Sebastes mentella . Locus-by-locus analyses revealed that only five microsatellite loci out of nine used could discriminate the concerned species. The advantage of the Bayesian methods relies in the individual information retrieved. It therefore gave additional information on the interrelationship among species. Indeed, we provide evidence of potential hybridization among species as well as individual misclassification based on morphological identification. We provide a powerful tool to discriminate North Atlantic redfish species, which might be useful for legal issues such as poaching, unintentional harvesting and control label.
Nilsen, Bente Merete - One of the best experts on this subject based on the ideXlab platform.
-
Fremmedstoffer i snabeluer (Sebastes mentella) og vanlig uer (Sebastes norvegicus) - Sluttrapport for kartleggingsprogrammet «Miljøgifter i fisk og fiskevarer» 2016-2018
Havforskningsinstituttet, 2020Co-Authors: Nilsen, Bente Merete, Frantzen Sylvia, Sanden MonicaAbstract:I dette arbeidet er det gjennomført en omfattende kartlegging av viktige fremmedstoffer i snabeluer (Sebastes mentella) og vanlig uer (Sebastes norvegicus) fra norske farvann. Konsentrasjonene av tungmetaller og organiske miljøgifter i filet av 522 snabeluer og 223 vanlig uer var generelt lave. Nivåene var noe lavere i vanlig uer enn i snabeluer, og i begge arter var nivåene betydelig lavere enn grenseverdiene som gjelder for kvikksølv, kadmium, bly, sum dioksiner, sum dioksiner og dioksinlignende PCB og sum ikke-dioksinlignende PCB (PCB6) i fiskefilet til humant konsum i Norge og EU. Konsentrasjonene i lever var høyere enn i filet, og nivået av kadmium i lever av snabeluer var uvanlig høyt i forhold til nivåene i lever av andre fiskearter fra norske farvann. Én enkelt samleprøve av lever fra snabeluer hadde et innhold av dioksiner og dioksinlignende PCB over grenseverdien for humant konsum. Konsentrasjonene av fremmedstoffer varierte mellom de ulike områdene der fisken var fanget, og variasjonsmønsteret mellom områdene var svært likt for de fleste av fremmedstoffene. For vanlig uer var det en tydelig nord-sør gradient i nivåene med høyest nivåer i de sørligste områdene, men for snabeluer var det ingen tydelig geografisk trend. Funnene i denne undersøkelsen har vist at selv om snabeluer og vanlig uer er arter som vokser sent og lever lenge, er nivåene av fremmedstoffer i filet av disse artene lave.publishedVersio
-
Fremmedstoffer i snabeluer (Sebastes mentella) og vanlig uer (Sebastes norvegicus) - Sluttrapport for kartleggingsprogrammet «Miljøgifter i fisk og fiskevarer» 2016-2018
Havforskningsinstituttet, 2020Co-Authors: Nilsen, Bente Merete, Frantzen Sylvia, Sanden MonicaAbstract:I dette arbeidet er det gjennomført en omfattende kartlegging av viktige fremmedstoffer i snabeluer (Sebastes mentella) og vanlig uer (Sebastes norvegicus) fra norske farvann. Konsentrasjonene av tungmetaller og organiske miljøgifter i filet av 522 snabeluer og 223 vanlig uer var generelt lave. Nivåene var noe lavere i vanlig uer enn i snabeluer, og i begge arter var nivåene betydelig lavere enn grenseverdiene som gjelder for kvikksølv, kadmium, bly, sum dioksiner, sum dioksiner og dioksinlignende PCB og sum ikke-dioksinlignende PCB (PCB6) i fiskefilet til humant konsum i Norge og EU. Konsentrasjonene i lever var høyere enn i filet, og nivået av kadmium i lever av snabeluer var uvanlig høyt i forhold til nivåene i lever av andre fiskearter fra norske farvann. Én enkelt samleprøve av lever fra snabeluer hadde et innhold av dioksiner og dioksinlignende PCB over grenseverdien for humant konsum. Konsentrasjonene av fremmedstoffer varierte mellom de ulike områdene der fisken var fanget, og variasjonsmønsteret mellom områdene var svært likt for de fleste av fremmedstoffene. For vanlig uer var det en tydelig nord-sør gradient i nivåene med høyest nivåer i de sørligste områdene, men for snabeluer var det ingen tydelig geografisk trend. Funnene i denne undersøkelsen har vist at selv om snabeluer og vanlig uer er arter som vokser sent og lever lenge, er nivåene av fremmedstoffer i filet av disse artene lave