subject:(Physa)

Oklahoma State University

1. Wells, Allison. Reproductive life history decisions and success of freshwater pond snails (Physa acuta) during chronic zinc exposure.

Degree: Integrative Biology, 2019, Oklahoma State University

URL: http://hdl.handle.net/11244/324920

► Life history theory examines how individuals should make trade-offs between current reproductive effort and survival to achieve future reproductive gains. A prediction is that as… (more)

▼ Life history theory examines how individuals should make trade-offs between current reproductive effort and survival to achieve future reproductive gains. A prediction is that as future life expectancy decreases, individuals should invest more in current reproduction at the cost of lower survival and future reproduction. Although P. acuta have been shown to display a relatively high tolerance to anthropogenic contaminants and pollutants, research regarding sub-lethal chronic exposure to contaminants and reproductive effort is limited. However, it has been shown that higher zinc concentrations lower P. acuta survival rates. Therefore, the objective of this study was to determine if chronic sub-lethal exposure to zinc has the potential to alter an individual's reproductive life history decisions, and if the magnitudes of these decisions are dependent upon a site's historic zinc exposure. Snails were collected from 3 sites within the Grand Lake watershed that have different zinc concentrations. Their offspring were then exposed to one of 5 zinc concentrations over the course of ~18 weeks. Individuals from these sites showed differences in response to zinc treatments. Individuals from historically moderate zinc concentrations followed life history predictions most closely, as an increase in zinc treatment resulted in earlier timing of reproductive events and growth. However, individuals from historically low zinc exposure showed delayed growth and reproduction as zinc concentration increased. Individuals from high historic zinc exposure in general displayed few negative effects from the zinc treatments, likely due to a high zinc tolerance among these individuals. Overall, results showed evidence of a gradient of local adaptation and tolerance of zinc. Tolerance seemed to be a key factor in whether individuals make life history changes in response to metal contamination. Advisors/Committee Members: Luttbeg, Barney (advisor), Towner, Mary (committee member), Belden, Jason (committee member).

Subjects/Keywords: life history; physa; reproduction; tolerance; zinc

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APA (6^th Edition):

Wells, A. (2019). Reproductive life history decisions and success of freshwater pond snails (Physa acuta) during chronic zinc exposure. (Thesis). Oklahoma State University. Retrieved from http://hdl.handle.net/11244/324920

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Wells, Allison. “Reproductive life history decisions and success of freshwater pond snails (Physa acuta) during chronic zinc exposure.” 2019. Thesis, Oklahoma State University. Accessed April 17, 2021. http://hdl.handle.net/11244/324920.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Wells, Allison. “Reproductive life history decisions and success of freshwater pond snails (Physa acuta) during chronic zinc exposure.” 2019. Web. 17 Apr 2021.

Vancouver:

Wells A. Reproductive life history decisions and success of freshwater pond snails (Physa acuta) during chronic zinc exposure. [Internet] [Thesis]. Oklahoma State University; 2019. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/11244/324920.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wells A. Reproductive life history decisions and success of freshwater pond snails (Physa acuta) during chronic zinc exposure. [Thesis]. Oklahoma State University; 2019. Available from: http://hdl.handle.net/11244/324920

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Texas A&M University

2. Garza, Mark Isaac. Predator induced defenses in prey with diverse predators.

Degree: MS, Wildlife and Fisheries Sciences, 2006, Texas A&M University

URL: http://hdl.handle.net/1969.1/3309

► Phenotypic plasticity is an environmentally based change in phenotype and can be adaptive. Often, the change in an organism's phenotype is induced by the presence… (more)

▼ Phenotypic plasticity is an environmentally based change in phenotype and can be adaptive. Often, the change in an organism's phenotype is induced by the presence of a predator and serves as a defense against that predator. Defensive phenotypes are induced in freshwater physid snails in response to both crayfish and molluscivorous fish. Alternative morphologies are produced depending on which of these two predators snails are raised with, thus protecting them from each of these predators' unique mode of predation. Snails and other mollusks have been shown to produce thicker, differently shaped shells when found with predators relative to those found without predators. This production of thicker, differently shaped shells offers better protection against predators because of increased predator resistance. The first study in this thesis explores costs and limits to plasticity using the snailfish- crayfish system. I exposed juvenile physid snails (using a family structure) to either early or late shifts in predation regimes to assess whether developmental flexibility is equally possible early and late in development. Physid snails were observed to produce alternative defensive morphologies when raised in the presence of each of the two predators. All families responded similarly to the environment in which they were raised. Morphology was found to be heritable, but plasticity itself was not heritable. Morphology was found to become less flexible as snails progressed along their respective developmental pathways. In the second study, I raised physid snails with and without shell-crushing sunfish and examined the differences in shell thickness, shell mass, shell size and shell microstructural properties between the two treatment groups. Shells of snails raised with predators were found to be larger, thicker and more massive than those raised without predators, but differences in microstructure were found to be insignificant. I conclude that the observed shell thickening is accomplished by the snails' depositing more of the same material into their shells and not by producing a more complex shell composition. Advisors/Committee Members: DeWitt, Thomas J. (advisor), Coganto, Anthony I. (committee member), Fitzgerald, Lee (committee member).

Subjects/Keywords: inducible defenses; shell morphology; Physa; Lepomis microlophus; morphometrics

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APA (6^th Edition):

Garza, M. I. (2006). Predator induced defenses in prey with diverse predators. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/3309

Chicago Manual of Style (16^th Edition):

Garza, Mark Isaac. “Predator induced defenses in prey with diverse predators.” 2006. Masters Thesis, Texas A&M University. Accessed April 17, 2021. http://hdl.handle.net/1969.1/3309.

MLA Handbook (7^th Edition):

Garza, Mark Isaac. “Predator induced defenses in prey with diverse predators.” 2006. Web. 17 Apr 2021.

Vancouver:

Garza MI. Predator induced defenses in prey with diverse predators. [Internet] [Masters thesis]. Texas A&M University; 2006. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/1969.1/3309.

Council of Science Editors:

Garza MI. Predator induced defenses in prey with diverse predators. [Masters Thesis]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/3309

3. Moore, Alexandria C. Taxonomic and Morphological Evaluation of an Endemic Freshwater Gastropod.

Degree: MS, Ecology and Evolutionary Biology, 2013, University of Michigan

URL: http://hdl.handle.net/2027.42/98979

► Mollusks are the second most diverse animal phylum in terms of number of described species and nonmarine mollusks are among the most imperiled groups of… (more)

▼ Mollusks are the second most diverse animal phylum in terms of number of described species and nonmarine mollusks are among the most imperiled groups of invertebrate taxa. In particular, freshwater and terrestrial mollusks have the highest number of documented extinctions of any major taxonomic group. Such extinctions are not without their consequences as nonmarine mollusks provide several ecosystem functions including regulation of rates of primary production, decomposition, water clarity, and nutrient cycling. Given this and the level of fluidity found within freshwater mollusk taxonomy, the proper identification of potentially endangered species is an issue of great concern. The present study evaluates the taxonomic status of a small freshwater snail endemic to southeastern Oregon within the Owyhee River, referred to here as the Owyhee physa. Molecular, morphological, and environmental analyses were employed using specimens from both a sister species, “Physa gyrina”, and another species with similar morphology and habitat conditions as the Owyhee physa, Physa zionis. Molecular analyses also incorporated supplemental sequences from other physid species to assess the status of the Owyhee physa within the Physidae family. Genetic analyses at the cytochrome oxidase 1 and ITS-1 and ITS-2 gene regions indicate that the Owyhee physa is a phylogenetically distinct species with “Physa gyrina” as its sister species. Using theoretical morphological techniques, the shell morphology of each of the three physid species was qualitatively described. Qualitative analyses of these morphological descriptions along with the phylogenetic tree and environmental data for each species suggests that convergent evolution played an important role in influencing shell morphology within this taxonomic group. The present work has provided additional information about the current status of Physidae species richness, but additional studies must be done to both broaden and deepen our knowledge of freshwater gastropod diversity. Advisors/Committee Members: Duda, Thomas F. (advisor), Burch, John B. (committee member), Dick, Christopher W. (committee member), Pappas, Janice L. (committee member).

Subjects/Keywords: Mollusks, Physa, Taxonomy, Conservation, Morphology, Evolution; Science - Conservation Genetics

…referred to here as the Owyhee physa. Molecular, morphological, and environmental analyses were… …employed using specimens from both a sister species, “Physa gyrina”, and another species with… …similar morphology and habitat conditions as the Owyhee physa, Physa zionis. Molecular analyses… …the Owyhee physa within the Physidae family. Genetic analyses at the cytochrome oxidase 1… …and ITS-1 and ITS-2 gene regions indicate that the Owyhee physa is a phylogenetically…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Moore, A. C. (2013). Taxonomic and Morphological Evaluation of an Endemic Freshwater Gastropod. (Masters Thesis). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/98979

Chicago Manual of Style (16^th Edition):

Moore, Alexandria C. “Taxonomic and Morphological Evaluation of an Endemic Freshwater Gastropod.” 2013. Masters Thesis, University of Michigan. Accessed April 17, 2021. http://hdl.handle.net/2027.42/98979.

MLA Handbook (7^th Edition):

Moore, Alexandria C. “Taxonomic and Morphological Evaluation of an Endemic Freshwater Gastropod.” 2013. Web. 17 Apr 2021.

Vancouver:

Moore AC. Taxonomic and Morphological Evaluation of an Endemic Freshwater Gastropod. [Internet] [Masters thesis]. University of Michigan; 2013. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/2027.42/98979.

Council of Science Editors:

Moore AC. Taxonomic and Morphological Evaluation of an Endemic Freshwater Gastropod. [Masters Thesis]. University of Michigan; 2013. Available from: http://hdl.handle.net/2027.42/98979

University of New Mexico

4. Nolan, Journey R. Molecular characterization of the freshwater snail Physella acuta.

Degree: UNM Biology Department, 2013, University of New Mexico

URL: https://digitalrepository.unm.edu/biol_etds/87

► Current insights into general animal biology, including immune function, are derived mostly from a few model organisms, a necessity imposed by effort required for in-depth… (more)

Subjects/Keywords: gastropod; Physella acuta; Physa acuta; mitochondria; mitogenomics; transcriptomics; 454; next generational sequencing; Biomphalaria glabrata; gene rearrangements; dN/dS; Ka/Ks; intraspecific sequence differences; invertebrate immunology; lophotrochozoa; Mollusca; FREP

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Nolan, J. R. (2013). Molecular characterization of the freshwater snail Physella acuta. (Masters Thesis). University of New Mexico. Retrieved from https://digitalrepository.unm.edu/biol_etds/87

Chicago Manual of Style (16^th Edition):

Nolan, Journey R. “Molecular characterization of the freshwater snail Physella acuta.” 2013. Masters Thesis, University of New Mexico. Accessed April 17, 2021. https://digitalrepository.unm.edu/biol_etds/87.

MLA Handbook (7^th Edition):

Nolan, Journey R. “Molecular characterization of the freshwater snail Physella acuta.” 2013. Web. 17 Apr 2021.

Vancouver:

Nolan JR. Molecular characterization of the freshwater snail Physella acuta. [Internet] [Masters thesis]. University of New Mexico; 2013. [cited 2021 Apr 17]. Available from: https://digitalrepository.unm.edu/biol_etds/87.

Council of Science Editors:

Nolan JR. Molecular characterization of the freshwater snail Physella acuta. [Masters Thesis]. University of New Mexico; 2013. Available from: https://digitalrepository.unm.edu/biol_etds/87

East Carolina University

5. Gordon, Katherine E. TEMPERATURE, RESOURCE INPUT, AND STANDING GENETIC VARIATION AFFECT PREDATOR RESPONSES OF PHYSA ACUTA.

Degree: MS, MS-Biology, 2019, East Carolina University

URL: http://hdl.handle.net/10342/7260

► In urban areas, features such as high percentages of impervious ground cover, patchiness, and storm water runoff can lead to increases in temperature and external… (more)

▼ In urban areas, features such as high percentages of impervious ground cover, patchiness, and storm water runoff can lead to increases in temperature and external nutrient input into aquatic systems. Such factors can lead to changes in primary productivity, and thus the growth rates of primary consumers, as well as the vulnerability of primary consumers to predation. Additionally, isolated populations due to patchiness of natural areas in urban environments can lead to inbred populations, which can also influence growth rates and vulnerability of primary consumers. To assess how such factors can influence interspecific interactions, we test how temperature, resource availability, and standing genetic variation of the freshwater snail Physa acuta affects the snail's anti-predator responses and life history characteristics. We conducted an experiment in which we reared snails from inbred or wild-caught lineages at high or low temperatures, with high and low resource inputs, and with or without chemical cues of crayfish (Procambarus clarkii) predation. We assessed how these treatments affected predator avoidance behavior, anti-predator morphological responses, reproductive output, and survival. We found that snails reared in high temperatures, and with low resource availability were unable to exhibit typical morphological responses to predators. We also found that snails were more likely to exhibit anti-predator behaviors when resource availability was low and when temperatures were high, and that behavioral responses to predators were higher for inbred snails than wild-caught snails. Snail survival was significantly affected by temperature, resource availability, and standing genetic variation. Reproductive output of snails was also affected by temperature, resource availability, predator cue presence, and standing genetic variation. These results indicate that features common in urban systems can influence not only individuals' ability to persist in these environments, but also can have effects on species interactions in ways that can cascade through food webs and potentially change ecosystem functions. Advisors/Committee Members: McCoy, Michael W. (advisor).

Subjects/Keywords: Behavioral Avoidance; Phenotypic Plasticity; Physa acuta; Resource Availability; Predation (Biology) – Environmental aspects; Temperature – Environmental aspects; Variation (Biology); Snails – Behavior; Predatory animals – Ecology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Gordon, K. E. (2019). TEMPERATURE, RESOURCE INPUT, AND STANDING GENETIC VARIATION AFFECT PREDATOR RESPONSES OF PHYSA ACUTA. (Masters Thesis). East Carolina University. Retrieved from http://hdl.handle.net/10342/7260

Chicago Manual of Style (16^th Edition):

Gordon, Katherine E. “TEMPERATURE, RESOURCE INPUT, AND STANDING GENETIC VARIATION AFFECT PREDATOR RESPONSES OF PHYSA ACUTA.” 2019. Masters Thesis, East Carolina University. Accessed April 17, 2021. http://hdl.handle.net/10342/7260.

MLA Handbook (7^th Edition):

Gordon, Katherine E. “TEMPERATURE, RESOURCE INPUT, AND STANDING GENETIC VARIATION AFFECT PREDATOR RESPONSES OF PHYSA ACUTA.” 2019. Web. 17 Apr 2021.

Vancouver:

Gordon KE. TEMPERATURE, RESOURCE INPUT, AND STANDING GENETIC VARIATION AFFECT PREDATOR RESPONSES OF PHYSA ACUTA. [Internet] [Masters thesis]. East Carolina University; 2019. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10342/7260.

Council of Science Editors:

Gordon KE. TEMPERATURE, RESOURCE INPUT, AND STANDING GENETIC VARIATION AFFECT PREDATOR RESPONSES OF PHYSA ACUTA. [Masters Thesis]. East Carolina University; 2019. Available from: http://hdl.handle.net/10342/7260

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