Compounds related to the high-production-volume flame retardant Dechlorane Plus (DP) were measured in a Lake Ontario food web located downstream of a DP manufacturing plant. These compounds, 1,3- and 1,5-DP-monoadducts (DPMA), are positional isomers and are thought to arise from the incomplete reaction of DP or impurities in the DP starting material during its manufacture. The 1,3-DPMA isomer was measured (0.12-199 ng g(-1) lipid wt) in all trophic levels, whereas 1,5-DPMA was measured only sporadically in the food web and was not detectable in the apex predator, lake trout (Salvelinus namaycush). Concentrations of DPMA isomers when detected in Lake Ontario biota were greater than that of total DP for all trophic levels. The prevalence of 1,3-DPMA in the food web, and especially in lake trout, may be due to obstruction of the existing carbon double bond to enzyme attack, rendering it less readily metabolized. To examine this hypothesis, biotransformation kinetic experiments using in vitro lake trout liver microsomal exposures were performed. Zero-order depletion rate constants for 1,3- and 1,5-DPMA were 92.2 and 134.6 pmole h(-1) , respectively, with corresponding half-lives of 2.03 ± 0.14 h (1,3-DPMA) and 1.39 ± 0.09 h (1,5-DPMA). Furthermore, the 1,5-isomer was depleted to a greater extent than 1,3-DPMA. Specific biotransformation products were not identified. These data support the hypothesis that 1,5-DPMA is more readily metabolized than 1,3-DPMA by lake trout. The present study also shows that the concentrations of these isomers, which the authors speculate might be unintended impurities or byproducts in some technical DP formulations, exceed that of the intended product in biota.
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http://dx.doi.org/10.1002/etc.2199 | DOI Listing |
Biol Lett
January 2025
Department of Forestry and Natural Resources, Purdue University, Forestry Building, 195 Marsteller Street, West Lafayette, IN 47907, USA.
Temperate fishes often spawn in response to environmental cues, such as temperature, thereby facilitating larval emergence concurrent with suitable biotic and abiotic conditions, such as plankton blooms. Climatic changes may alter the reproductive phenology of spring- and autumn-spawning freshwater fish populations. Such effects may depend on the sensitivity of reproductive phenology to ambient temperatures.
View Article and Find Full Text PDFBiology (Basel)
December 2024
Laboratory of Experimental Ecology and Aquaculture, Department of Biology, University of Rome "Tor Vergata", Via Cracovia 1, 00133 Rome, Italy.
Due to their involvement in pathogen-mediated immune responses, the hypervariable genes of the Major Histocompatibility Complex (MHC) have become a paradigm for investigating the evolution and maintenance of genetic (adaptive) diversity, contextually providing insight into the viability of wild populations, which is meaningful for conservation. Here, we provide the first preliminary characterization of MHC polymorphism and evolution in trouts from Albania, a known hotspot of Salmonid diversity harboring ecologically and phylogenetically distinct native (threatened) taxa. Overall, 36 trout-including Lake Ohrid-endemic and , and both riverine and lacustrine native brown trout (the complex) from the Drin-Skadar drainage-were genotyped at the MHC- locus through next-generation amplicon sequencing.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Toxicology Centre, University of Saskatchewan, Saskatoon S7N 5B3, Canada.
-(1,3-Dimethylbutyl)-'-phenyl--phenylenediamine-quinone (6PPD-Q) is a rubber-tire derivative which leaches into surface waters from roadway runoff, from tire particles and has been identified as a possible driver of urban runoff mortality syndrome in coho salmon. Sensitivity to this toxicant is highly variable across fish species and life stages. With environmental concentrations meeting or exceeding toxicity thresholds in sensitive fishes, the potential for ecologically relevant effects is significant.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montreal, QC, H4B 1R6, Canada.
Intraspecific variation is important for species' long-term persistence in changing environments. Conservation strategies targeting intraspecific variation often rely on the identification of management or policy units below the species level based on biological differences among populations. To identify management units, this paper examines intraspecific divergence of Lake Trout (Salvelinus namaycush) in Great Slave Lake (GSL), Canada, using low-coverage whole-genome sequencing data.
View Article and Find Full Text PDFEvol Dev
March 2025
Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
The evolution of adaptive phenotypic divergence requires heritable genetic variation. However, it is underappreciated that trait heritability is molded by developmental processes interacting with the environment. We hypothesized that the genetic architecture of divergent functional traits was dependent on age and foraging environment.
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