The ScholarShip

The ScholarShip is a digital archive for the scholarly output of the ECU community. Its mission is to capture, preserve, and make available the intellectual output of East Carolina University's faculty, staff, and students.

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Now showing 1 - 8 of 8

Recent Submissions

Access status: Metadata only ,
Asymmetrical effects of temperature on stage-structured predator-prey interactions
(2021-03-02)
Warming can impact consumer-resource interactions through multiple mechanisms. For example, warming can both alter the rate at which predators consume prey and the rate prey develop through vulnerable life stages. Thus, the overall effect of warming on consumer-resource interactions will depend upon the strength and asymmetry of warming effects on predator and prey performance. Here, we quantified the temperature dependence of both 1) density-dependent predation rates for two dragonfly nymph predators on a shared mosquito larval prey, via the functional response, and 2) the development rate of mosquito larval prey to a predator-invulnerable adult stage. We united the results of these two empirical studies using a temperature- and density-dependent stage-structured predation model. Warming accelerated both larval mosquito development and increased dragonfly consumption. Model simulations suggest that differences in the magnitude and rate of predator and prey responses to warming determined the change in magnitude of the overall effect of predation on prey survival to adulthood. Specifically, we found that depending on which predator species prey were exposed to in the model, the net effect of warming was either an overall reduction or no change in predation strength across a temperature gradient. Our results highlight a need for better mechanistic understanding of the differential effects of temperature on consumer-resource pairs to accurately predict how warming affects food web dynamics.
Access status: Metadata only ,
Transcriptome data: salinity adaptation in Rhithropanopeus harrisii across an estuarine gradient
(2021-06-04)
"Rhithropanopeus harrisii is a common estuarine crab native to the East and Gulf Coasts of North America. Here, it is found along a broad range of salinities, spanning from ~1 PSU to ~25 PSU along estuarine gradients. As part of a larger study on the species' potential use of low-salinity refuges from parasitism, we tested for differences in gene expression with salinity using crabs from three distinct estuarine reaches along the Pamlico River in North Carolina. We acclimated crabs collected at natural sites with 1, 5, and 11 PSU mean salinity to 0.8, 3, and 15 PSU in the laboratory for one week and sequenced gill tissue (second posterior gill) from each group using mRNA-Seq. Data in this repository includes information on sequenced samples (*csv), the de novo transcriptome assembly (two versions: with and without expression filtering; *.fasta), transcriptome annotation from EnTAP (two files: using the runN and runP functions; *.tsv), a spreadsheet of normalized read count data from salmon pseudo-alignment (*.tsv), high-quality SNPs identified from the transcriptome sequencing with GATK (*.vcf), and three custom scripts used in processing the SNP data (*.py and *.R). Raw sequence data is archived in GenBank's SRA: BioProject PRJNA730785, BioSamples SAMN19241288-SAMN19241333."
Access status: Metadata only ,
Invasion history shapes host transcriptomic response to a body-snatching parasite
(2021-06-21)
By shuffling biogeographic distributions, biological invasions can both disrupt long-standing associations between hosts and parasites and establish new ones. This creates natural experiments with which to study the ecology and evolution of host-parasite interactions. In estuaries of the Gulf of Mexico, the white-fingered mud crab (Rhithropanopeus harrisii) is infected by a native parasitic barnacle Loxothylacus panopaei (Rhizocephala), which manipulates host physiology and behavior. In the 1960s, L. panopaei was introduced to the Chesapeake Bay and has since expanded along the southeastern Atlantic coast, while host populations in the northeast have so far been spared. We use this system to test the host’s transcriptomic response to parasitic infection and investigate how this response varies with the parasite’s invasion history, comparing populations representing (1) long-term sympatry between host and parasite, (2) new associations where the parasite has invaded during the last sixty years, and (3) naïve hosts without prior exposure. A comparison of parasitized and control crabs revealed a core response, with widespread downregulation of transcripts involved in immunity and molting. The transcriptional response differed between hosts from the parasite’s native range and where it is absent, consistent with previous observations of increased susceptibility in populations lacking exposure to the parasite. Crabs from the parasite’s introduced range, where prevalence is highest, displayed the most dissimilar response, possibly reflecting immune priming. These results provide molecular evidence for parasitic manipulation of host phenotype and the role of gene regulation in mediating host-parasite interactions.
Access status: Metadata only ,
Bivalve facilitation mediates seagrass recovery from physical disturbance in a temperate estuary
(2021-11-10)
This dataset describes two experiments done in seagrass beds in Back Sound, North Carolina. Experiment 1 was¬†located in a large contiguous shallow seagrass bed near Cape Lookout, NC (34.668121, -76.509455) and Experiment 2¬†was located in the Rachel Carson Estuarine Reserve, Beaufort, NC (34.698799, -76.595439). Experiment 1 was a clam-addition/control experiment, and 2018/2019 summer growth rates, 2018/2019 summer biomass cores, and 2018/2019 epiphytic load on Zostera marina¬†and¬†Halodule wrightii¬†were sampled. Experiment 2 was a two-factor experiment looking at clam-addition and excavation and 2019 summer growth rates, 2019/2020 summer biomass cores, and 2019/2020 recolonization and percent cover were sampled.¬†To document the spatial characteristics of the experimental areas, we mapped the extent of the contiguous seagrass bed and the coordinates of the experimental plots and subplots with a Trimble R10 Integrated GNSS system in May 2018, June 2018, and July 2019 for Experiment 1 and April 2019 and July 2019 for Experiment 2 in the NAD83 coordinate system.
Access status: Metadata only ,
King Rail and Common Moorhen egg pattern matching data
(2021-12-02)
This dataset is a combination of egg images and processed output on pattern matching of eggshell surfaces from the images using NaturePatternMatch (NPM), additional data extracted from NPM, and field data. The data are separated into four folders based on species and analyses performed. There are two folders of scaled single egg images, one for King Rails, Rallus elegans, and one for Common Moorhens, Gallinula chloropus chloropus. Each photograph is identified by year, clutch and egg identity. Most of the Common Moorhen eggs are numbered in the order of their laying sequence, and they are further identified by laying hen. The NMDS folder includes NPM matching output and clutch identities needed to perform NMDS and PERMANOVA analyses. It includes consolidated and organized output from NPM for each species as well as files with clutch names needed to create merged datasets for graphing. These data were used to perform non-metric multidimensional scaling (NMDS) and permutational analysis of variance (PERMANOVA). The Linear Discriminant Analyses folder includes field data (egg length, width, and identity), pattern data extracted from NPM, as well as the estimated proportion of pigment measured within a scaled oval on binary images of eggs. This was used as a proxy for the relative amount of pigmentation on each egg. These data were used to conduct linear discriminant analyses for each species.