Life Sciences Commons^™

Non-Adaptive Phentypic Plasticity: Morphology, But Not Swim Speed, Of Spotted Salamander Larvae Is Affected By "Terrestrial" And "Aquatic" Herbicides, Mitchell Schooler

Mahurin Honors College Capstone Experience/Thesis Projects

1. Phenotypic plasticity, although ubiquitous, may not always be advantageous. In cases where individuals expressing an induced phenotype outperform non-induced individuals, the phenotypic plasticity is considered adaptive. Conversely, if the individuals with an induced phenotype underperform relative to non-induced individuals, then the plasticity is maladaptive. A final possibility is that both induced and non-induced individuals perform equally well (or poorly). This would be a case of non-adaptive (i.e. neutral) phenotypic plasticity.
2. We investigated the mode of phenotypic plasticity induced by four glyphosate-based herbicides in larvae of the spotted salamander, Ambystoma maculatum (Shaw, 1802), by determining whether the herbicides induced different morphologies, …

Level Of Uv-B Radiation Influences The Effects Of Glyphosate-Based Herbicide On Fitness Of The Spotted Salamander, Nicholas A. Levis

Masters Theses & Specialist Projects

Numerous causes have been implicated in contributing to amphibian population declines since the 1980's, with habitat modification, ultraviolet radiation (UV-B) and environmental contaminants (such as glyphosate-based herbicide) being among the most common. This study identifies the effects of a generic glyphosate-based herbicide (GLY- 4 Plus) on mortality, immune function, body condition, and morphological plasticity of larvae of the spotted salamander (Ambystoma maculatum) under conditions that reflect open and closed canopy light regimes. Larval salamander responses to glyphosate-based herbicide varied depending on UV-B conditions. In general, it appears that an open canopy (i.e. greater UV-B exposure) may confer fitness benefits. In …