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Population genetic analysis of invasive populations can provide valuable insights into the source of introductions, pathways for expansion, and their demographic histories. Flathead catfish (Pylodictis olivaris) are a prolific invasive species with high fecundity, long‐distance dispersal, and piscivorous feeding habits that can lead to declines in native fish populations. In this study, we analyse the genetics of invasive P. olivaris in the Mid‐Atlantic region to assess their connectivity and attempt to reconstruct the history of introduced populations. Based on an assessment across 13 microsatellite loci, P. olivaris from the Susquehanna River system (N = 537), Schuylkill River (N = 33), and Delaware River (N = 1) have low genetic diversity (global Hobs = 0.504), although we detected no evidence of substantial inbreeding (FIS = −0.083 to 0.022). P. olivaris from these different river systems were genetically distinct, suggesting separate introductions. However, population structure was much weaker within each river system and exhibited a pattern of high connectivity, with some evidence of isolation by distance. P. olivaris from the Susquehanna and Schuylkill rivers showed evidence for recent genetic bottlenecks, and demographic models were consistent with historical records, which suggest that populations were established by recent founder events consisting of a small number of individuals. Our results show the risk posed by small introductions of P. olivaris, which can spread widely once a population is established, and highlight the importance of prevention and sensitive early detection methods to prevent the spread of P. olivaris in the future. [ABSTRACT FROM AUTHOR]

We document the isolation and characterization of 14 tetranucleotide microsatellite DNA markers in Preble's meadow jumping mouse ( Zapus hudsonius preblei). The identified markers displayed moderate levels of allelic diversity (averaging 4.9 alleles per locus) and heterozygosity (averaging 55.1%). Genotypic and allelic frequencies in a collection of 30 individuals conformed to Hardy–Weinberg equilibrium expectations and indicated no linkage disequilibrium. High levels of cross-amplification (95% overall) among neighbouring subspecies and two congeners ( Zapus princeps and Zapus trinotatus) were observed. Multilocus genotypes resulting from these markers appear to provide ample genetic diversity for studies assessing individual- and population–level ecological interactions within Z. h. preblei and evolutionary relationships among neighbouring subspecies ( Z. h. campestris, Z. h. intermedius, Z. h. pallidus and Z. h. luteus). [ABSTRACT FROM AUTHOR]

We have sequenced the female and male mtDNA of Unio delphinus and inferred the Unionidae phylogeny using 41 complete mtDNA sequences. Additionally, we compared the concatenated mtDNA trees with those using single or combination of two mtDNA genes to identify the best genes to use in the absence of complete mitogenomes. The gender-specific mtDNAs of U. delphinus contain all Unionida mtDNA specific features. The mtDNA phylogeny supports the reciprocal monophyly of the gender-specific clades but it was inconclusive regarding Unionidae subfamilies relationships. The gene trees topologies using ND5 or 16S-rRNA with ND1 were the closest trees to the mtDNA trees., Competing Interests: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government., (© 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)