Five diagnostic codominant nuclear DNA markers and a diagnostic mitochondrial DNA marker were use... more Five diagnostic codominant nuclear DNA markers and a diagnostic mitochondrial DNA marker were used to survey weakfish (Cynoscion regalis) and sand seatrout (C. arenarius), with particular focus on heretofore uncharacterized juvenile populations along the Florida (FL) Atlantic coast. Geographic and reproductive ranges of weakfish and sand seatrout were shown to overlap on the Atlantic coast along north and central FL. An active bidirectional zone of introgressive hybridization exists between these taxa, centered in the St Johns River, FL. Strong patterns of Hardy–Weinberg, linkage, and cytonuclear disequilibrium and a bimodal hybrid index distribution were observed for juvenile cohorts in the zone center, coupled with narrow (;240 km) concordant clines. Parental forms had disparate habitat preferences; hybrid forms occurred predominantly in intermediate habitats. All genetic data were consistent with the hypothesis that the C. arenarius–C. regalis hybrid zone is maintained by a dynam...
While investigating hybridization in shoal bass Micropterus cataractae in the Chipola River, Flor... more While investigating hybridization in shoal bass Micropterus cataractae in the Chipola River, Florida, we encountered a distinctive genetic signature from an unknown taxon. We soon pinpointed the signature’s source to a novel form of bass inhabiting the rivers of the East Gulf Coastal Plain. Superficially, these bass resemble spotted bass M. punctulatus and have mistakenly been considered as such. Genetically, they can be diagnosed by four autapomorphies at two nuclear gene introns and one mtDNA gene and by various clustering techniques using 17 microsatellite loci. In nuclear-gene phylogenies based on 10 sequenced introns, this reciprocally monophyletic taxon shares a common ancestor with spotted bass and Guadalupe bass M. treculii; remaining micropterids are more distantly related. Morphologically, they differ from spotted bass, Alabama bass M. henshalli, and Guadalupe bass in mean/modal counts of soft anal-fin and dorsal-fin rays. They further appear to differ from Guadalupe bass ...
International organizations and biodiversity scientists recognize three levels of biodiversity: g... more International organizations and biodiversity scientists recognize three levels of biodiversity: genetic, species, and ecosystem. However, most studies with the goal of assessing biodiversity collect data at only a single level -- that of the species. Even when multiple levels of biodiversity are considered, usually only ecosystem diversity is also evaluated. Genetic diversity is virtually never considered. Yet, genetic diversity is essential for the maintenance of populations and species over ecological and evolutionary time periods. Moreover, because components of genetic diversity are independent of either species or ecosystem diversity, genetic diversity can provide a unique measure by which to assess the value of regions for conservation. Regions can be valuable for conservation of their genetic resources regardless of their levels of species or ecosystem uniqueness or diversity. In general, the same methods and statistical programs that are used to answer questions about popula...
Transactions of the American Fisheries Society, 1999
The purposes of this study were to evaluate the present species classification, to develop geneti... more The purposes of this study were to evaluate the present species classification, to develop genetic methods for diagnosing morphologically indistinguishable juveniles, and to investigate the potential for introgressive hybridization for species of the percoid fish genus Centropomus (Pisces: Centropomidae). We analyzed specimens representing all nominal species using allozyme electrophoretic data and sequence data from a 618-base-pair portion of the mitochondrial
North American Journal of Fisheries Management, 1995
... f .. 0 . . r i_ n iti r na^ been introduced only a tew years earlier. ... stocked into Sunape... more ... f .. 0 . . r i_ n iti r na^ been introduced only a tew years earlier. ... stocked into Sunapee Lake. Although old records show that sabling were imported into New Hamp-shire, no records demonstrate that these fish were ever put into Sunapee Lake (Goode 1887; Kendall 1913). ...
Five diagnostic codominant nuclear DNA markers and a diagnostic mitochondrial DNA marker were use... more Five diagnostic codominant nuclear DNA markers and a diagnostic mitochondrial DNA marker were used to survey weakfish (Cynoscion regalis) and sand seatrout (C. arenarius), with particular focus on heretofore uncharacterized juvenile populations along the Florida (FL) Atlantic coast. Geographic and reproductive ranges of weakfish and sand seatrout were shown to overlap on the Atlantic coast along north and central FL. An active bidirectional zone of introgressive hybridization exists between these taxa, centered in the St Johns River, FL. Strong patterns of Hardy–Weinberg, linkage, and cytonuclear disequilibrium and a bimodal hybrid index distribution were observed for juvenile cohorts in the zone center, coupled with narrow (;240 km) concordant clines. Parental forms had disparate habitat preferences; hybrid forms occurred predominantly in intermediate habitats. All genetic data were consistent with the hypothesis that the C. arenarius–C. regalis hybrid zone is maintained by a dynam...
While investigating hybridization in shoal bass Micropterus cataractae in the Chipola River, Flor... more While investigating hybridization in shoal bass Micropterus cataractae in the Chipola River, Florida, we encountered a distinctive genetic signature from an unknown taxon. We soon pinpointed the signature’s source to a novel form of bass inhabiting the rivers of the East Gulf Coastal Plain. Superficially, these bass resemble spotted bass M. punctulatus and have mistakenly been considered as such. Genetically, they can be diagnosed by four autapomorphies at two nuclear gene introns and one mtDNA gene and by various clustering techniques using 17 microsatellite loci. In nuclear-gene phylogenies based on 10 sequenced introns, this reciprocally monophyletic taxon shares a common ancestor with spotted bass and Guadalupe bass M. treculii; remaining micropterids are more distantly related. Morphologically, they differ from spotted bass, Alabama bass M. henshalli, and Guadalupe bass in mean/modal counts of soft anal-fin and dorsal-fin rays. They further appear to differ from Guadalupe bass ...
International organizations and biodiversity scientists recognize three levels of biodiversity: g... more International organizations and biodiversity scientists recognize three levels of biodiversity: genetic, species, and ecosystem. However, most studies with the goal of assessing biodiversity collect data at only a single level -- that of the species. Even when multiple levels of biodiversity are considered, usually only ecosystem diversity is also evaluated. Genetic diversity is virtually never considered. Yet, genetic diversity is essential for the maintenance of populations and species over ecological and evolutionary time periods. Moreover, because components of genetic diversity are independent of either species or ecosystem diversity, genetic diversity can provide a unique measure by which to assess the value of regions for conservation. Regions can be valuable for conservation of their genetic resources regardless of their levels of species or ecosystem uniqueness or diversity. In general, the same methods and statistical programs that are used to answer questions about popula...
Transactions of the American Fisheries Society, 1999
The purposes of this study were to evaluate the present species classification, to develop geneti... more The purposes of this study were to evaluate the present species classification, to develop genetic methods for diagnosing morphologically indistinguishable juveniles, and to investigate the potential for introgressive hybridization for species of the percoid fish genus Centropomus (Pisces: Centropomidae). We analyzed specimens representing all nominal species using allozyme electrophoretic data and sequence data from a 618-base-pair portion of the mitochondrial
North American Journal of Fisheries Management, 1995
... f .. 0 . . r i_ n iti r na^ been introduced only a tew years earlier. ... stocked into Sunape... more ... f .. 0 . . r i_ n iti r na^ been introduced only a tew years earlier. ... stocked into Sunapee Lake. Although old records show that sabling were imported into New Hamp-shire, no records demonstrate that these fish were ever put into Sunapee Lake (Goode 1887; Kendall 1913). ...
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