Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

Dates: Last 2 Years

You searched for subject:(Physa). Showing records 1 – 2 of 2 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


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

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

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

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

APA (6th 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 (16th 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 19, 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 (7th Edition):

Wells, Allison. “Reproductive life history decisions and success of freshwater pond snails (Physa acuta) during chronic zinc exposure.” 2019. Web. 19 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 19]. 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


East Carolina University

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

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

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

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

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

APA (6th 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 (16th 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 19, 2021. http://hdl.handle.net/10342/7260.

MLA Handbook (7th Edition):

Gordon, Katherine E. “TEMPERATURE, RESOURCE INPUT, AND STANDING GENETIC VARIATION AFFECT PREDATOR RESPONSES OF PHYSA ACUTA.” 2019. Web. 19 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 19]. 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

.