Body condition ( ) and reproductive potential of bighead and silver carp hybrids: Postzygotic selection in the Mississippi River Basin.

Invasive bighead () and silver carp () are reproductively isolated in their native range, but form a bimodal, multigenerational hybrid swarm within the Mississippi River Basin (MRB). Despite observed F 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 ( ) and female reproductive potential (presence of spawning stage gonads and gonadosomatic index [GSI]) in the MRB during 2009-2011.

Seeing red: color vision in the largemouth bass.

How animals visually perceive the environment is key to understanding important ecological behaviors, such as predation, foraging, and mating. This study focuses on the visual system properties and visual perception of color in the largemouth bass . This study (1) documents the number and spectral sensitivity of photoreceptors, (2) uses these parameters to model visual perception, and (3) tests the model of color perception using a behavioral assay.

Diagnostic SNPs reveal widespread introgressive hybridization between introduced bighead and silver carp in the Mississippi River Basin.

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.

Elements of concern in fillets of bighead and silver carp from the Illinois River, Illinois.

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.

Restriction site-associated DNA sequencing generates high-quality single nucleotide polymorphisms for assessing hybridization between bighead and silver carp in the United States and China.

Bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix) are invasive species and listed as US federally injurious species under the Lacy Act. They have established populations in much of the Mississippi River Basin (MRB; Mississippi, Illinois, and Missouri rivers) and are capable of producing fertile hybrids and complex introgression.

Spatial and interspecific patterns in persistent contaminant loads in bighead and silver carp from the Illinois River.

We measured concentrations of selected organohalogens, fluorinated compounds and mercury in whole, ground silver (Hypophthalmichthys molitrix) and bighead (H. nobilis) carp from the Illinois River, Illinois, in 2010 and 2011 to characterize spatial and interspecific patterns of contaminant burdens. Silver carp, which had greater lipid content, tended to have greater concentrations of lipophilic compounds.