ABSTRACT ACCUMULATION OF ENVIRONMENTAL AND DIETARY HEAVY METALS BY THE WOLF SPIDER PARDOSA MILVINA (ARANEAE, LYCOSIDAE) by Lucas Christopher Erickson Invertebrates provide a key link in moving toxic heavy metals from the environment into the vertebrate food web. Studying the uptake and accumulation of metals in invertebrates can help explain bioaccumulation of metals further up the food web. In this study, I decoupled dietary and substrate exposure to heavy metals and quantified accumulation of cadmium, copper, lead, and zinc in the epigeic wolf spider Pardosa milvina. I also looked at how foraging and lifespan might change in response to heavy metal exposure. I found that P. milvina absorbs and accumulates all four of these heavy metals through its cuticle. However, only metals that also are micronutrients (e.g. zinc) were accumulated from dietary consumption; non-nutritive metals were excreted without accumulation. Female mortality was not affected by heavy metal exposure, while male mortality was negatively affected by substrate exposure to metals but not by dietary exposure. As P. milvina is a common prey item for a variety of vertebrate and invertebrate species, it likely provides a vector for heavy metals to move from the soils into the vertebrate food web. ACCUMULATION OF ENVIRONMENTAL AND DIETARY HEAVY METALS BY THE WOLF SPIDER PARDOSA MILVINA (ARANEAE, LYCOSIDAE) A Thesis Submitted to the Faculty of Miami University in partial fulfillment of the requirements for the degree of Master of Science by Lucas Christopher Erickson Miami University Oxford, Ohio 2018 Advisor: Dr. Ann Rypstra Reader: Dr. Al Cady Reader: Dr. Melany Fisk ©2018 Lucas Christopher Erickson This Thesis titled ACCUMULATION OF ENVIRONMENTAL AND DIETARY HEAVY METALS BY THE WOLF SPIDER PARDOSA MILVINA (ARANEAE, LYCOSIDAE) by Lucas Christopher Erickson has been approved for publication by The College of Arts and Science and Department of Biology ____________________________________________________ Dr. Ann Rypstra ______________________________________________________ Dr. Al Cady _______________________________________________________ Dr. Melany Fisk Table of Contents List of Tables ................................................................................................................................ iv List of Figures ................................................................................................................................ v Dedication ..................................................................................................................................... vi Acknowledgements ..................................................................................................................... vii Introduction ................................................................................................................................... 1 Methods .......................................................................................................................................... 5 Results .......................................................................................................................................... 10 Discussion..................................................................................................................................... 12 Future Studies ............................................................................................................................. 16 Literature Cited .......................................................................................................................... 17 Tables/Figures ............................................................................................................................. 21 Appendix ...................................................................................................................................... 40 iii List of Tables Table 1 .......................................................................................................................................... 25 Table 2 .......................................................................................................................................... 26 Table 3 .......................................................................................................................................... 27 Table 4 .......................................................................................................................................... 28 Table 5 .......................................................................................................................................... 29 Table 6 .......................................................................................................................................... 30 Table 7 .......................................................................................................................................... 31 Table 8 .......................................................................................................................................... 32 iv List of Figures Figure 1 ........................................................................................................................................ 33 Figure 2 ........................................................................................................................................ 34 Figure 3 ........................................................................................................................................ 35 Figure 4 ........................................................................................................................................ 36 Figure 5 ........................................................................................................................................ 37 Figure 6 ........................................................................................................................................ 38 Figure 7 ........................................................................................................................................ 39 Figure 8 ........................................................................................................................................ 40 Figure 9 ........................................................................................................................................ 41 Figure 10 ...................................................................................................................................... 42 Figure 11 ...................................................................................................................................... 43 v Dedication For my parents. Thanks for everything. vi Acknowledgments There are quite a few people I need to thank for their help and support in getting through graduate school. First and foremost is my advisor Ann Rypstra; without her guidance, none of this work would have been possible. In addition, I would like to thank my committee members Al Cady and Melany Fisk for their insight and feedback throughout my work. Thank you to Mary Gardiner and James Harwood for supplying me with the heavy metal contaminated soil. Thanks as well to John Morton for his help with ICP-MS, especially in working with small amounts of biomass. Thanks to everyone in the Rypstra lab for their help and support (both scientific and emotional) during my time at Miami. An especially heartfelt thank you goes out to Amber Dailey, who has provided constant motivation and support, whether she knew it or not. And finally, thanks to the undergraduate professors that nurtured my spark of scientific curiosity: Bob Verb, Jay Mager, Leslie Riley, Stephen Kolomyjec, and Terry Keiser. Without them, I wouldn’t have applied to graduate school in the first place. vii Introduction Environmental contamination with heavy metals is a pressing concern for both human and environmental health (UNEP 2013). The risks posed by heavy metals have increased in recent decades as human use of heavy metals and their release into the environment has increased (Tchounwou et al. 2012). Anthropogenic activities from industrialization such as burning of fossil fuels and mining are primary drivers of heavy metal deposition into the environment (Alloway 2012). As growing populations in developing countries are increasingly industrialized, the impact of heavy metals in the environment is expected to increase (Nagajyoti et al. 2010). Heavy metals can have negative ecological effects at both individual and population levels (Alloway 2012). Individual exposure to heavy metals may impair development, damage neurological function, cause systemic damage, or otherwise interfere with physiological processes (Tchounwou et al. 2012). Heavy metals may also have non-lethal effects that reduce population viability. Exposure of fish to non-lethal concentrations of heavy metals impaired swimming ability (Eissa et al. 2010), while increased mercury exposure has been tied to reduced nesting rates in bird populations (Heath and Frederick 2005). Heavy metal uptake and accumulation has been widely studied in vertebrates, but has received relatively little attention in soil arthropods (Gall et al. 2015). Furthermore, the majority of arthropod studies have focused on detritivores and herbivores, ignoring how heavy metals may move through the invertebrate food web into predators (Gall et al. 2015). Field studies have shown that heavy