A Comparison of Mercury Localization, Speciation, and Histology in Multiple Fish Species From Caddo Lake, a Fresh Water Wetland

PDF Version Also Available for Download.

Description

This work explores the metabolism of mercury in liver and spleen tissue of fish from a methylmercury contaminated wetland. Wild-caught bass, catfish, bowfin and gar were collected. Macrophage centers, which are both reactive and primary germinal centers in various fish tissues, were hypothesized to be the cause of demethylation of methylmercury in fish tissue. Macrophage centers are differentially expressed in fish tissue based on phylogenetic lineage, and are found primarily in the livers of preteleostean fish and in the spleen of teleostean fish. Histology of liver and spleen was examined in both control and wild-caught fish for pathology, size and ... continued below

Creation Information

Smith, James Durward May 2012.

Context

This dissertation is part of the collection entitled: UNT Theses and Dissertations and was provided by UNT Libraries to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 1757 times , with 24 in the last month . More information about this dissertation can be viewed below.

Who

People and organizations associated with either the creation of this dissertation or its content.

Chair

Committee Members

Publisher

Rights Holder

For guidance see Citations, Rights, Re-Use.

  • Smith, James Durward

Provided By

UNT Libraries

With locations on the Denton campus of the University of North Texas and one in Dallas, UNT Libraries serves the school and the community by providing access to physical and online collections; The Portal to Texas History and UNT Digital Libraries; academic research, and much, much more.

Contact Us

What

Descriptive information to help identify this dissertation. Follow the links below to find similar items on the Digital Library.

Degree Information

Description

This work explores the metabolism of mercury in liver and spleen tissue of fish from a methylmercury contaminated wetland. Wild-caught bass, catfish, bowfin and gar were collected. Macrophage centers, which are both reactive and primary germinal centers in various fish tissues, were hypothesized to be the cause of demethylation of methylmercury in fish tissue. Macrophage centers are differentially expressed in fish tissue based on phylogenetic lineage, and are found primarily in the livers of preteleostean fish and in the spleen of teleostean fish. Histology of liver and spleen was examined in both control and wild-caught fish for pathology, size and number of macrophage centers, and for localization of mercury. Total mercury was estimated in the muscle tissue of all fish by direct mercury analysis. Selenium and mercury concentrations were examined in the livers of wild-caught fish by liquid introduction inductively coupled plasma mass spectrometry (ICP-MS). Total mercury was localized in histologic sections by laser ablation ICP-MS (LA-ICP-MS). Mercury speciation was determined for inorganic and methylmercury in liver and spleen of fish by bas chromatography-cold vapor atomic fluorescence spectroscopy (GC-CVAFS). Macrophage center tissue distribution was found to be consistent with the literature, with a predominance of centers in preteleostean liver and in spleens of teleostean fish. Little evidence histopathology was found in the livers or spleens of fish examined, but differences in morphology of macrophage centers and liver tissue across species are noted. the sole sign of liver pathology noted was increased hepatic hemosiderosis in fish with high proportions of liver inorganic mercury. Inorganic mercury was found to predominate in the livers of all fish but bass. Organic mercury was found to predominate in the spleens of all fish. Mercury was found to accumulate in macrophage centers, but concentrations of mercury in this compartment were found to vary less in relation to total mercury than hepatocyte mercury. No association was found between selenium content and inorganic mercury proportions. Overall, findings from this study to not support a primary role for macrophage centers in the demethylation of methylmercury in fish tissues.

Language

Collections

This dissertation is part of the following collection of related materials.

UNT Theses and Dissertations

Theses and dissertations represent a wealth of scholarly and artistic content created by masters and doctoral students in the degree-seeking process. Some ETDs in this collection are restricted to use by the UNT community.

What responsibilities do I have when using this dissertation?

When

Dates and time periods associated with this dissertation.

Creation Date

  • May 2012

Added to The UNT Digital Library

  • Nov. 6, 2012, 3:03 p.m.

Description Last Updated

  • June 27, 2017, 11:15 a.m.

Usage Statistics

When was this dissertation last used?

Yesterday: 0
Past 30 days: 24
Total Uses: 1,757

Interact With This Dissertation

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Smith, James Durward. A Comparison of Mercury Localization, Speciation, and Histology in Multiple Fish Species From Caddo Lake, a Fresh Water Wetland, dissertation, May 2012; Denton, Texas. (digital.library.unt.edu/ark:/67531/metadc115162/: accessed April 25, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .