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Introduction
I use molecular genetics to answer fishy questions.
Additional affiliations
September 2010 - present
University of Windsor
September 2009 - August 2011
Publications
Publications (67)
Objective
The objectives of this work are to isolate, develop, and characterize polymorphic microsatellite markers for use in Greenland sharks ( Somniosus microcephalus ).
Results
Thirteen microsatellite loci were successfully amplified and yielded multi-locus genotypes for 36 S. microcephalus individuals from Grise Fjord (n = 16) and Svalbard (n...
Although genetic techniques are moving toward collecting massive amounts of genome-wide data through genome-scans, microsatellite markers (µsats) still provide a simple and cost-effective method for key applications such as parentage analyses, pedigree tracking, assessing likelihoods of disease conditions and DNA fingerprinting, among others. Newer...
We report the complete mitogenome for the California grunion (Leuresthes tenuis), a beach-spawning silverside fish endemic to eastern Pacific coastal waters of California, USA and Baja California, Mexico. Approximately, 28,428 short reads from a shotgun gDNA library were mapped to a reference mitogenome of Menidia menidia. The resulting L. tenuis m...
Long-lived species share life history traits such as slow growth, late maturity, and low fecundity, which lead to slow recovery rates and increase a population’s vulnerability to disturbance. The Greenland shark (Somniosus microcephalus) has recently been recognized as the world’s longest-lived vertebrate, but many questions regarding its biology,...
Herein, we use genetic data from 277 sleeper sharks to perform coalescent-based modeling to test the hypothesis of early Quaternary emergence of the Greenland shark (Somniosus microcephalus) from ancestral sleeper sharks in the Canadian Arctic-Subarctic region. Our results show that morphologically cryptic somniosids S. microcephalus and Somniosus...
Inferences made from molecular data support regional stock assessment goals by providing insights into the genetic population dynamics of enigmatic species. Population genomics metrics, such as genetic diversity and population connectivity, serve as useful proxies for species health and stability. Sleeper sharks (genus Somniosus) are ecologically i...
Among tropical organisms, heightened habitat specialization, limited natal dispersal, and strong philopatry suggests that many species may experience reduced rates of gene flow. Diverse forms of barriers, including geographic, ecological, and behavioural barriers, further promote genetic divergence among tropical bird populations. Here we extend ou...
Human activity can put non-game fishes at higher risk of extinction due to inappropriate management action. Eastern sand darter (Ammocrypta pellucida), a small benthic fish classified as threatened across much of its northern range, inhabits increasingly fragmented sandy habitats and, as a non-game fish, may be easily overlooked in conservation eff...
Many coral reef fishes are fished, often resulting in detrimental genetic effects; however, reef fishes often show unpredictable patterns of genetic variation, which potentially mask the effects of fishing. Our goals were to characterize spatial and temporal genetic variation and determine the effects of fishing on an exploited reef fish, Plectropo...
Objective The objectives of this research are to isolate, develop and characterize polymorphic microsatellite markers for use in Greenland sharks ( Somniosus microcephalus ). Despite utility in population analyses, microsatellite markers have not been previously developed for this species. Development of these markers, and successful amplification...
Objective: The objectives of this work are to isolate, develop, and characterize polymorphic microsatellite markers for use in Greenland sharks (Somniosus microcephalus).
Results: Thirteen microsatellite loci were successfully amplified and yielded multi-locus genotypes for 36 S. microcephalus individuals from Grise Fjord (n = 16) and Svalbard (n =...
Objective: The objectives of this work are to isolate, develop, and characterize polymorphic microsatellite markers for use in Greenland sharks (Somniosus microcephalus).
Results: Thirteen microsatellite loci were successfully amplified and yielded multi-locus genotypes for 36 S. microcephalus individuals from Grise Fjord (n = 16) and Svalbard (n =...
Background/Question/Methods:
Greenland sharks (Somniosus microcephalus) are long-lived marine predators that have endured various harvesting pressures, yet their conservation is hindered by little knowledge of their populations. Given the technical constraints of observing these deep-dwelling sharks, molecular genetic methods can be used to reveal...
A fundamental hypothesis about vocal learning is that young animals learn vocalizations in their natal areas and, following postnatal dispersal, they may introduce new types of vocalizations into their breeding areas. We tested this hypothesis in a tropical bird, the Rufous-and-white Wren (Thryophilus rufalbus), a species in which both sexes produc...
Given the important role that animal vocalizations play in mate attraction and resource defence, acoustic signals are expected to play a significant role in speciation. Most studies, however, have focused on the acoustic traits of male animals living in the temperate zone. In contrast to temperate environments, in the tropics it is commonplace for...
Urbanisation is widely associated with a suite of physical, chemical and biological degradation of stream ecosystems, known as "urban stream syndrome." It is unclear whether urban stream syndrome is applicable to oceanic islands, where marine dispersal of larvae enables diadromous species to continuously recolonise even highly degraded urban stream...
The extraction and characterization of DNA from aquatic environmental samples offers an alternative, non-invasive approach for the detection of rare species. Environmental DNA, coupled with PCR and next-generation sequencing (“metabarcoding”), has proven to be very sensitive for the detection of rare aquatic species. Our study used a custom designe...
A large reef manta ray (Manta alfredi) aggregation has been observed off the north Sudanese Red Sea coast since the 1950s. Sightings have been predominantly within the boundaries of a marine protected area (MPA), which was designated a UNESCO World Heritage Site in July 2016. Contrasting economic development trajectories have been proposed for the...
Mean monthly turbidity, represented by Kd(490), the diffuse attenuation coefficient at 490 nm, one indicator of water column turbidity derived from AquaMODIS satellite data.
The data for each month is scaled separately such that, blue shows the lowest mean turbidity and red shows highest mean turbidity for each month. The legends show the turbidity...
Wildlife Computers® SPOT 5 tag being attached to the dorsal fin of a reef manta ray (Manta alfredi) using nylon bolts.
The reef manta ray is secured to the side of the vessel with ropes.
(TIF)
Satellite derived mean monthly variation in (a) sea surface temperature, (b) chlorophyll-a and (c) turbidity, as represented by Kd(490) the diffuse attenuation coefficient at 490 nm, which is one indicator of the turbidity of the water column, for Dungonab Bay and Mukkawar Island National Park (DMNP) (from Klaus, R. 2016 Final Draft Management Plan...
Supplementary data file “Kessel et al raw manta SPOT tag data.csv” contains raw unfiltered SPOT 5 tag data received from all three manta rays.
Manta 1 (PTT 122197), manta 2 (PTT 122198), and manta 3 (PTT 122199).
(CSV)
Monthly mean chlorophyll-a concentrations (AquaMODIS) illustrating the seasonal changes in primary productivity in the Sudanese Red Sea.
The white line shows the Exclusive Economic Zone (EEZ) of Sudan (source: VLIZ 2008). Values shown are the concentration of chlorophyll-a (mg/l). The data for each month is scaled separately, where blue shows low p...
Raw location data received from reef manta rays, colour coded by location accuracy from excellent (red– 3) to poor (blue–B).
(TIF)
Species introductions are a widely recognized threat to global freshwater biodiversity. The proliferation of non-native species can result in the loss of native species through direct and indirect interactions with predators, competitors, pathogens and parasites. Thus identifying invasion hotspots and understanding the capacity of vulnerable ecosys...
We present genetic and morphometric support for a third, distinct, and recently diverged group of Manta ray that appears resident to the Yucatán coastal waters of the Gulf of Mexico. Individuals of the genus Manta from Isla Holbox are markedly different from the other described manta rays in their morphology, habitat preference, and genetic makeup....
Joint peak locations and posterior probabilities for 25 models in L-mode IMa2. P-values obtained using 2LLR as Chi-Square statistic. Bold models were not rejected following LLR tests
Manta identification
AIC for models not-rejected following LLR tests from IMa2 L-mode run
Genbank accession numbers for ND5 Manta haplotypes
Several studies have demonstrated that environmental DNA (eDNA) can be used to detect the presence of aquatic species, days to weeks after the target species has been removed. However, most studies used eDNA analysis in lentic systems (ponds or lakes), or in controlled laboratory experiments. While eDNA degrades rapidly in all aquatic systems, it a...
It is widely accepted that insular terrestrial biodiversity progresses with island age because colonization and diversification proceed over time. Here we assess whether this principle extends to oceanic island streams. We examined range-wide mtDNA sequence variation in four stream-dwelling species across the Hawaiian archipelago to characterize th...
Understanding the genetic background of invading species can be crucial information clarifying why they become invasive. Intraspecific genetic admixture among lineages separated in the native ranges may promote the rate and extent of an invasion by substantially increasing standing genetic variation. Here we examine the genetic relationships among...
Nutrient-rich, turbid river plumes that are common to large lakes and coastal marine ecosystems have been hypothesized to benefit survival of fish during early life stages by increasing food availability and (or) reducing vulnerability to visual predators. However, evidence that river plumes truly benefit the recruitment process remains meager for...
Understanding the spatial context of genetic variation for species at risk is important for effective management and long-term survival of the species. We use multilocus microsatellite data to investigate the population genetic structure of the spotted gar (Lepisosteus oculatus) across its northern range edge in Canada. We then compare these northe...
Quantifying spatial genetic structure can reveal the relative influences of contemporary and historic factors underlying localized and regional patterns of genetic diversity and gene flow – important considerations for the development of effective conservation efforts. Using 10 polymorphic microsatellite loci, we characterize genetic variation amon...
Life-stage-based management of marine fishes requires information on juvenile habitat preferences to ensure sustainable population demographics. This is espe-cially important in the Arctic region given very little is known about the life histories of many native species, yet exploitation by developing commercial and artisanal fisher-ies is increasi...
Finding novel techniques to sample species that are uncommon, small, or secretive are essential to collect genetic diversity and distribution information with minimal impact on habitat or harm to the species (e.g. stress). Environmental DNA (eDNA) was extracted from water samples from two major river systems in Southwest Ontario, Canada: Grand Rive...
The influence of habitat fragmentation on population dynamics within watersheds is not well understood, particularly for species known to disperse great distances. Effective conservation management, however, relies in part on an understanding of the role connectivity plays in maintaining viable populations over time and space. This study examined w...
Piscivore stomach contents represent naturally filtered environmental samples. Here we use DNA recovered from the stomach contents of predatory fish species to genetically identify prey species providing a method to characterize predator diets, trophic relationships, and assess the presence of non-native species. First we evaluated the number of st...
Molecular genetic laboratory exercises can be ineffective due the student's lack of connection to the complex and sequential protocols. In this inquiry-based molecular genetic laboratory exercise, we harness students' fascination with human forensics and provide a real-life scenario using biomolecular techniques to identify "whose blood is on the t...
Hybridization can complicate the effective conservation of cryptic and morphologically similar species. Here we provide a rapid genetic method for the identification of pure-strain brown bullhead (Ameiurus
nebulosus) and black bullhead (Ameiurus
melas) using nuclear and mitochondrial DNA restriction fragment length polymorphism assays. We confirm e...
Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg 2013 Following a recent taxonomic revision, two manta spe-cies (Manta alfredi and Manta birostris) have been advocated based on meristic and morphological charac-teristics (Marshall et al. 2009). Subsequent genetic analyses of the two species using mitochondrial and n...
Following a recent taxonomic revision, two manta species (Manta alfredi and Manta birostris) have been advocated based on meristic and morphological characteristics (Marshall et al. 2009). Subsequent genetic analyses of the two species using mitochondrial and nuclear markers confirmed two distinguishable genetic groups (Kashiwagi et al. 2012). Usin...
Populations existing in formerly glaciated areas often display composite historical and contemporary patterns of genetic structure. For Canadian freshwater fishes, population genetic structure is largely reflective of dispersal from glacial refugia and isolation within drainage basins across a range of scales. Enhancement of sport fisheries via hat...
Invasive fish species can have major impacts on freshwater faunas, particularly in isolated systems harbouring adaptive animal radiations. Here, we report on the occurrence and recent rapid expansion of the hybridogenic "flowerhorn" cichlid in ancient Lake Matano, the hydrological head of the Malili Lakes system in Central Sulawesi, Indonesia. We s...
Questions remain about the taxonomy and distribution of geographically widespread species in the circumtropical gobiid genus Awaous. Previous work that placed two species in synonymy on the basis of morphological characteristics effectively redefined the range of Awaous guamensis to include distant locations from Hawai’i and Guam to the islands of...
Species introductions in freshwater eco-systems are often complex processes, yet an under-standing of the nature of the introduction can inform management and conservation actions. The greenside darter (Etheostoma blennioides), until recently a species of special concern, expanded its Canadian range and is now common and widespread in the Grand Riv...
Amphidromous fishes are important members of oceanic island freshwater communities. Although often depauperate, amphidromous fish assemblages on islands are largely composed of endemic species. Little is known about the effects of anthropogenic stressors on amphi - dromous fishes, and the consequences of climate-driven changes in water quality and...
Spatially restricted endemic species are of special conservation concern as their narrow distributions render them particularly
vulnerable to extinction through habitat loss. However, estimates of connectivity among populations can provide a basis for
targeted conservation action. Here we quantify population genetic structure and connectivity for t...
Ten polymorphic microsatellite loci were isolated for the Awaous guamensis, an amphidromous gobiid common to the Hawai'ian islands. The loci show a moderate to high degree of allelic diversity and observed levels of heterozygosity ranged from 0.13 to 0.87. Most loci conformed to Hardy-Weinberg equilibrium (HWE) and showed little evidence of linkage...
Diversification of freshwater fishes on islands is considered unlikely because the traits that enable successful colonization-specifically, broad salinity tolerances and the potential for oceanic dispersal-may also constrain post-colonization genetic differentiation. Some secondary freshwater fish, however, exhibit pronounced genetic differentiatio...
This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergi...
Beacham and Withler (2010. Can. J. Fish. Aquat. Sci. 67: 202–205) raise concerns about the experimental design and interpretation of data in the analysis of temporal genetic variation of Chinook salmon (Oncorhynchus tshawytscha) from the Upper Fraser River, Canada (Walter et al. 2009. Can. J. Fish. Aquat. Sci. 66: 167–176). They note that for the s...
Coupled bio-physical models of larval dispersal predict that the Costa Rica–Panama (CR–PAN) reefs should constitute a demographically isolated region in the western Caribbean. We tested the hypothesis that CR–PAN coral reef fish populations would be isolated from Mesoamerican Barrier Reef System (MBRS) populations. To test that, we assessed populat...
We isolated and characterized eight polymorphic microsatellite loci for redside dace (Clinostomus elongatus), a colorful North American cyprinid that is threatened or endangered throughout most of its range. The number of alleles
per locus ranged from three to eighteen, with observed heterozygosity ranging from 0.31–0.92. Cross-amplification reveal...
Genetic divergence, assortative courtship and intermale aggression were assessed between sympatric colour morphs of the sailfin silverside Telmatherina antoniae, endemic to Lake Matano, Indonesia. Genetic analysis using microsatellite markers showed no barriers to gene flow among T. antoniae primary colour morphs (blue and yellow) within sampling s...
Temporal instability in population genetic structure has significant implications for management and conservation decisions. Here, we evaluate temporal stability in five populations of Chinook salmon (Oncorhynchus tshawytscha) from the Upper Fraser River, British Columbia, Canada, based on estimates of temporal allelic variance and effective popula...
Population genetic structure in the presence of substantial dispersal provides a unique perspective on the evolution of reproductive isolation. We sampled Telmatherina antoniae, an endemic fish species, at 10 sites in Lake Matano, Indonesia. Significant genetic structure (F(ST) = 0.03) was found, despite a migration rate of 10.2% and a mean dispers...
Ten primer pairs were designed from two genomic libraries enriched for (GACA) 4 and (GACA) 7 in the sailfin silverside Telmatherina antoniae . Characterization with 57 T. antoniae individuals revealed between three and 30 alleles, with observed and expected heterozy-gosity values ranging from 0.47 to 0.98 and from 0.46 to 0.93, respectively. Eight...
We measured abundance and diversity of fishes and corals at three patch reef complexes near San Salvador, Bahamas, and examined relationships among species and ecological measures of fish and coral community structure. Generalized Discriminant Analyses indicated which ecological variables distinguished reefs and which fish and coral species account...
The objective of our study was to determine habitat conditions in a stream
where walleye successfully produce fry and to compare these conditions with the
nationally-applicable Habitat Suitability Index (HSI) model for walleye. During 17-
20 d migration periods in April of 1996, 1997 and 2000, walleye were observed
spawning; eggs were collected pri...
Projects
Project (1)
We present genetic and morphometric support for a third, distinct, and recently diverged group of Manta ray that appears resident to the Yucatán coastal waters of the Gulf of Mexico. Individuals of the genus Manta from Isla Holbox are markedly different from the other described manta rays in their morphology, habitat preference, and genetic makeup. Herein referred to as the Yucatán Manta Ray, these individuals form two genetically distinct groups: (1) a group of mtDNA haplotypes divergent (0.78%) from the currently recognized Manta birostris and M. alfredi species, and (2) a group possessing mtDNA haplotypes of M. birostris and highly similar haplotypes.The latter suggests the potential for either introgressive hybridization between Yucatán Manta Rays and M. birostris, or the retention of ancestral M. birostris signatures among Yucatán Manta Rays. Divergence of the genetically distinct Yucatán Manta Ray from M. birostris appears quite recent (<100,000 YBP) following fit to an Isolation-with-Migration model, with additional support for asymmetrical gene flow from M. birostris into the Yucatán Manta Ray. Formal naming of the Yucatán Manta Ray cannot yet be assigned until an in-depth taxonomic study and further confirmation of the genetic identity of existing type specimens has been performed.