5/21/2015  |   10:30 - 10:45   |  103DE

EVOLUTIONARY DELINEATION AND CRYPTIC SPECIATION OF HYALELLA SPP. IN THE CHIHUAHUAN DESERT Vicariance-based speciation is an evolutionary process that has occurred in many freshwater systems. Aquatic invertebrates are especially prone to this type of speciation due to low dispersal ability, often forming cryptic species complexes. The amphipod Hyalella is widespread throughout all of North America, including the Pecos River drainage in the Chihuahuan Desert. We hypothesize that individual spring systems within this basin hold endemic, cryptic species of Hyalella. We also hypothesis that divergence will follow the stream hierarchy model and increase with river distance. To test these hypotheses we sequenced two mitochondrial genes (cytochrome oxidase subunit I and 16s rRNA) and one nuclear gene (28s rDNA), created a phylogeny, and calculated genetic divergence. Our results supported the presence of cryptic species by identifying five possible species. However, genetic variation did not follow the patterns expected in an isolation-by-distance model. This may be due to high mutation rates or greater dispersal abilities than previously expected. Populations of Hyalella exhibit great levels of genetic diversity and endemism in the Chihuahuan Desert; the presence of cryptic species with limited ranges merits conservation concern.

Trevor Williams (Primary Presenter/Author), Miami University, willi432@miamioh.edu;

5/21/2015  |   10:45 - 11:00   |  103DE

ECOLOGICAL DIFFERENTIATION IN A FRESHWATER MUSSEL SPECIES COMPLEX Obovaria jacksoniana and Villosa arkansasensis form a complex consisting of five clades in the lower Mississippi and Gulf Coast drainages. We used Maxent to create habitat suitability maps for the complex as a single species, for the two morphologically defined species, and for each of the five clades. We compared model fit among these taxonomic groupings and examined correlations among divergence time and niche overlap for pairs of clades using Mantel tests. Niche models for the five separate clades provided the best model fit. Models for each clade were significantly different from one another. We found a negative correlation between divergence time and niche overlap; thus, clades that diverged most recently occupied the most-similar niches. Recent speciation within this complex, likely due to geographic isolation, appears to have been accompanied by niche differentiation. Rather than two species, this complex consists of five species that are distinguishable both genetically and ecologically. While providing insight into the process of speciation, our study suggests that niche differentiation may be a useful measure for identifying taxonomic units of conservation interest.

ASHLEY D WALTERS (Primary Presenter/Author), Miami University, dunithad@miamioh.edu;


Kentaro Inoue (Co-Presenter/Co-Author), Texas A&M University, kentaro.inoue@ag.tamu.edu;


John Harris (Co-Presenter/Co-Author), Arkansas State University, omibob1@gmail.com;


DAVID J BERG (Co-Presenter/Co-Author), MIAMI UNIVERSITY, bergdj@miamioh.edu;

5/21/2015  |   11:00 - 11:15   |  103DE

PUTTING CONTAMINATION TO USE FOR REDUCING UNCERTAINTY IN ENVIRONMENTAL DNA MONITORING Genetic analysis of environmental DNA (eDNA) provides site occupancy inferences for rare aquatic macrofauna that are often easier to obtain than direct observations of organisms. Research on the origin, state, transport, and fate of environmental DNA (eDNA) from aquatic macrofauna is needed to describe the spatiotemporal context for eDNA-based occupancy inferences, and to guide eDNA sampling design. One often underestimated origin is contamination. Contamination sources, primarily PCR product and tissue, are abundant in most laboratories with interest and capacity to analyze eDNA. Unfortunately, standard precautions (i.e., autoclaving) are inadequate for destroying DNA contamination. Even worse, standard negative controls (i.e., water blanks) are inadequate for observing contamination occurrence and abundance. Having learned these old lessons the hard way, I present several case studies involving eDNA data that I ultimately concluded were best explained by contamination. These conclusions are supported by data from other fields making organismal inferences based solely on indirect genetic evidence from environmental samples: microbiology, forensics, paleogenetics, fecal source tracking, and agricultural transgene monitoring. Finally, I suggest a framework for accurately estimating contamination occurrence and abundance.

Cameron R. Turner (Primary Presenter/Author), ecoSystem Genetics LLC, crt343@gmail.com;

5/21/2015  |   11:15 - 11:30   |  103DE

BARCODING OF TRACE DNA IN CHIRONOMID PUPAL EXUVIAE REVEALS QUALITY DIFFERENCES IN DNA EXTRACTION PROTOCOLS Molecular tools, such as DNA barcoding, advance freshwater biomonitoring studies by allowing fast, cost-effective, and high-resolution identification for species-rich and abundant macroinvertebrates, like the Chironomidae (Diptera). Crucial for the success in the use of these tools is the performance of DNA extraction protocols. We tested six different extraction protocols on trace DNA in 570 carefully sampled chironomid pupal exuviae from two localities in Norway. Genomic DNA was isolated and the standard COI barcode sequenced successfully from 297 samples. The DNeasy® Blood & Tissue Kit produced the highest quality results (97% PCR and 34% sequences success), while the more economical QuickExtract™ solution produced results that were nearly as high (82% PCR and 35% sequence success). Out of the successfully sequenced barcodes, 14% were high-quality Chironomidae sequences matching species in the Barcode of Life Data Systems. Our results suggest that the best extraction protocols were sensitive in detecting trace amounts of DNA from multiple species present in the pupal exuviae samples, but that chironomid sequences often were masked by sequences from other taxa. Possible solutions to this will be discussed.

Petra Kranzfelder (Primary Presenter/Author), University of California, Santa Barbara, pkranzfelder@ucsb.edu;


Torbjørn Ekrem (Co-Presenter/Co-Author), Norwegian University of Science and Technology , torbjorn.ekrem@ntnu.no;


Elisabeth Stur (Co-Presenter/Co-Author), Norwegian University of Science and Technology, elisabeth.stur@ntnu.no;

5/21/2015  |   11:30 - 11:45   |  103DE

TAKING THE ANONYMITY OUT OF RAD-SEQUENCING: LINKING THOUSANDS OF SNP MARKERS WITH THE FIRST DRAFT GENOME SEQUENCE OF THE MELTWATER STONEFLY, LEDNIA TUMANA Next-generation sequencing (NGS) provides the foundation upon which genome-scale data are collected for natural populations. These datasets provide the empirical framework upon which the rapidly developing field of population genomics rests. One often-cited promise of NGS-based population genetics is to further extend these data to address questions involving selection and adaptation, and provide a more functional perspective on the evolution of populations. However, to realize this promise and develop the proper links between anonymous markers (e.g., restriction-site associated DNA or RAD) and the genome from which they are sampled, a solid understanding of the genome, including its structure and gene ontology, is required. Here, we combine the collection of RAD data for the study of genetic variation across populations of Lednia tumana (Plecoptera: Nemouridae) with the first draft genome of the species. The results of this research provide not only greater context for our previously developed population-genomic markers, but also begin to provide insight into the presence of potential adaptive variation across the range of L. tumana in Glacier National Park, Montana.

Scott Hotaling (Primary Presenter/Author), Washington State University, scott.hotaling@uky.edu;


Clint C Muhlfeld (Co-Presenter/Co-Author), USGS Northern Rocky Mountain Science Center, cmuhlfeld@usgs.gov;


J. Joseph Giersch (Co-Presenter/Co-Author), Flathead Lake Biological Station, jgiersch@usgs.gov;


Michael R. Miller (Co-Presenter/Co-Author), UC Davis, micmiller@ucdavis.edu;


Richard Grewelle (Co-Presenter/Co-Author), University of Kentucky, richard.grewelle@uky.edu;


Deborah Lu (Co-Presenter/Co-Author), University of Kentucky, deborah.lu@uky.edu;


Steve P. Jordan (Co-Presenter/Co-Author), Bucknell University, steve.jordan@bucknell.edu;


Gordon Luikart (Co-Presenter/Co-Author), Flathead Lake Biological Station, The University of Montana, gordon.luikart@umontana.edu;


David Weisrock (Co-Presenter/Co-Author), University of Kentucky, dweis2@uky.edu;