SPECIES DISTRIBUTIONS AND TRAIT- ENVIRONMENT CORRELATIONS: IMPLICATIONS FOR THE EVOLUTIONARY ECOLOGY OF CRAYFISH (DECAPODA: CAMBARIDAE) By REID LANDEN MOREHOUSE Bachelor of Science in Fisheries and Aquatic Sciences Purdue University West Lafayette, IN 2006 Master of Science in Zoology Oklahoma State University Stillwater, OK 2010 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY July, 2014 SPECIES DISTRIBUTIONS AND TRAIT- ENVIRONMENT CORRELATIONS: IMPLICATIONS FOR THE EVOLUTIONARY ECOLOGY OF CRAYFISH (DECAPODA: CAMBARIDAE) Dissertation Approved: Dr. Michael Tobler Dissertation Adviser Dr. Punidan Jeyasingh Dr. Monica Papeş Dr. Andrew Dzialowski Dr. Shannon Brewer ii ACKNOWLEDGEMENTS This research would not have been possible without the advice, guidance, counseling and help from my friends and family. First, I am in great debt to my advisor, Dr. Michi Tobler. Without your never ending help and desire to push me to my limits, these projects would not have been possible. Your attitude towards me and my research allowed me to really dive right in without feeling pressured and stressed. The freedom and trust you gave me to run my own research allowed me to grow as an individual more than I ever would have thought. I could not have asked for a better advisor and friend. Next, I thank my committee members: Dr. Puni Jeyasingh, Dr. Andrew Dzialowski, Dr. Mona Papeş, and Dr. Shannon Brewer, for all of your faith and confidence in my research and myself. Your jokes, even at my expense, and overall general attitudes really help me keep a level head and push through the rough times. My laboratory mates, I give thanks to for putting up with my attitude when things were not going right, and for all of the great conversations that occurred. Special thanks to my close friends I have met during my time in Stillwater. I am not sure if I would have made it without you guys there supporting me. I owe so much to my parents for the time and energy they have put in, to make me the person I am today. I do not tell you two enough that I love you and appreciate everything you have done for me. I also need to thank my black lab, Memphis. No matter how bad of a day I had, you were always excited and happy to see me. Last but not least, I owe the world to my fiancé, Liz, for dealing with me during stressful times and always being there for me during the last two years of my research. I love you and will always be there for you. iii Acknowledgements reflect the views of the author and are not endorsed by committee members or Oklahoma State University. Name: REID LANDEN MOREHOUSE Date of Degree: JULY, 2014 Title of Study: SPECIES DISTRIBUTIONS AND TRAIT-ENVIRONMENT CORRELATIONS: IMPLICATIONS FOR THE EVOLUTIONARY ECOLOGY OF CRAYFISH (DECAPODA: CAMBARIDAE) Major Field: ZOOLOGY Abstract: Crayfish occur on every continent, except for Antarctica and Africa excluding Madagascar, and are a very diverse group of freshwater crustaceans with over 600 species. Crayfish are keystone species, ecosystems engineers, and make up the majority of invertebrate biomass in the systems they inhabit. In Oklahoma, there are 30 known species from six genera, with representatives from the three general ecological morphs that are defined by their burrowing behavior (burrowing types). In the first chapter, I provide a general overview and a synthesis of the questions addressed in my dissertation. The second chapter provides an in-depth account of Oklahoma’s crayfish and their biology, including an illustrated dichotomous key for species identification, individual species descriptions with color photographs, and detailed distribution maps. This chapter provided the foundation for research on crayfish biology in my subsequent chapters. Specifically, my studies focused on the 27 epigean species of Oklahoma to address questions regarding the effects of climate change and land use on species distributions (Chapter 3), quantifying morphological variation among taxa to test of the role of evolutionary convergence among burrowing types (Chapter 4), and investigating whether and how trophic resource partitioning can mediate the coexistence of sympatric species (Chapter 5). In Chapter 3, my results suggested that different crayfish burrowing types were affected by distinct bioclimatic variables. Crayfish distributions, however, did not appear to be negatively affected by climate change, and habitat destruction is likely a driving factor in the decline of crayfish. Differences among burrowing types were also highlighted in Chapter 4, which indicated consistent morphological trait variation in species of the same burrowing type, irrespective of taxonomic affiliation, providing evidence for convergent evolution in crayfish morphology. Finally, in Chapter 5, stable isotope analyses indicated that some crayfish species pairs partition their food resources, but there is also evidence for overlap in dietary niches. Overall, my dissertation provides a foundation for the study of crayfish within Oklahoma and surrounding states and provides a basis of better understanding the evolutionary and ecological mechanisms that have lead to and contributed to maintaining crayfish diversity in North America. iv TABLE OF CONTENTS Chapter Page I. INTRODUCTION AND SYNTHESIS ......................................................................1 Introduction and synthesis .......................................................................................1 Crayfish diversity, identification, and threats ...................................................1 Current paradigms of crayfish ecology: burrowing behavior and trophic generalists ..........................................................................................................3 Testing and refining current paradigms: a synthesis of subsequent chapters ....5 Literature Cited ........................................................................................................9 II. CRAYFISHES (DECAPODA : CAMBARIDAE) OF OKLAHOMA: IDENTIFICATION, DISTRIBUTIONS, AND NATURAL HISTORY ..............17 Introduction ............................................................................................................18 Oklahoma and its Crayfishes ...........................................................................19 Materials and Methods ...........................................................................................21 Dichotomous Key ............................................................................................21 Species profiles ................................................................................................21 Occurrence data ...............................................................................................23 Distribution modeling ......................................................................................24 Identification of biodiversity hotspots .............................................................26 Results ....................................................................................................................27 Dichotomous key for Oklahoma crayfish ........................................................27 Species accounts ..............................................................................................40 Discussion ..............................................................................................................81 Patterns of biodiversity and conservation priorities in Oklahoma ...................81 Future directions ..............................................................................................83 Acknowledgements ................................................................................................85 References ..............................................................................................................85 Glossary ...............................................................................................................117 III. IMPACTS OF CLIMATE CHANGE AND LAND COVER USE ON CRAYFISH DISTRIBUTIONS ...............................................................................................119 Introduction ..........................................................................................................120 Methods................................................................................................................125 v Occurrence data, current and future climatic layers, and ecological niche modeling ........................................................................................................125 Climatic variables shaping current distributions of different burrowing types ... ........................................................................................................................128 Distributional changes in response to climate change ...................................128 Land cover at known crayfish locations ........................................................129 Results ..................................................................................................................130 Climatic variables shaping current distributions of different burrowing types ... ........................................................................................................................130 Distributional changes in response to climate change ...................................130 Land cover at known crayfish locations