Cephalopods of the Broad Caribbean: Distribution, Abundance, and Ecological Importance by Heather L. Judkins A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy College of Marine Science University of South Florida Co-Major Professor: Joseph Torres, Ph.D. Co-Major Professor: Michael Vecchione, Ph.D. Susan Bell, Ph.D. David Mann, Ph.D. Mark Luther, Ph.D. Date of Approval: June 10, 2009 Keywords: mollusca, Caribbean diversity, biogeography, latitudinal gradients, coastal Atlantic Ocean ©Copyright 2009, Heather L. Judkins ACKNOWLEDGEMENTS I would like to acknowledge the team of people who have helped me through this process. Dr. Joseph Torres, Dr. Michael Vecchione, and my entire committee, Dr. Susan Bell, Dr. David Mann, and Dr. Mark Luther, have been instrumental in terms of advice, pathways to follow, and excellent sounding boards for my many questions. I would like to acknowledge Dr. Clyde Roper for his foresight in seeing that I had potential to add a small part of research to the cephalopod scientific community and his words of wisdom and encouragement throughout this entire venture. I would like to thank Dr. Nancy Voss for her advice and guidance in understanding of cephalopod species of the Broad Caribbean. Her assistance in my work is beyond compare. Dr. Ronald B. Toll and Dr. Steven C. Hess were instrumental in documenting cephalopod specimen information from the Hourglass Cruises that were conducted from 1965 through 1967, by the Marine Research Laboratory of the Florida Board of Conservation on the continental shelf of the Gulf of Mexico which was included in my dissertation. I also thank Teresa Greely and Angela Lodge for their assistance throughout the two years of my GK12 Oceans Fellowship and the opportunity to coordinate the regional competition for the National Ocean Sciences Bowl that I have been so excited to be a part of for the College of Marine Science at USF. Lastly, I wouldn’t be where I am without the unfailing support and constant source of smiles from my family and friends who have been there through the ups and downs of my journey. Thank you. TABLE OF CONTENTS TABLE OF CONTENTS i LIST OF TABLES iii LIST OF FIGURES iv ABSTRACT v CHAPTER 1. INTRODUCTION 1 1.1 Broad Caribbean 1 1.2 Cephalopod Biology 3 1.3 Distribution of Cephalopods 4 1.4 Abundance of Cephalopods 4 1.5 Cephalopods in Food Webs 5 1.6 Overall Significance 7 1.7 Study Goals 8 1.8. Study Area 9 1.9 Materials and Methods 9 1.10 References 13 CHAPTER 2. BIOGEOGRAPHY OF CEPHALOPODS OF THE BROAD CARIBBEAN 16 2.1 Introduction 16 Broad Caribbean 16 The Cephalopods 18 Biogeography of Cephalopods 18 Abundance of Cephalopods 21 Ecological Focus 21 Study Area 24 2.2 Materials and Methods 24 Statistical analysis 26 2.3 Results 27 Rapoport’s Rule and Species Richness 27 Cephalopod Biogeography 28 Distribution and Abundance 29 Range Extensions 29 New Species to Area 38 2.4 Discussion 38 Rapoport’s Rule and Species Richness 38 Cephalopod Biogeography 41 i Distribution and Abundance 43 Range Extensions 45 New Species 45 2.5 References 47 CHAPTER 3. CEPHALOPODA (MOLLUSCA: CEPHALOPODA) OF THE GULF OF MEXICO 52 3.1 Introduction 52 3.2 Major Systematic Revisions 56 3.3 Comparative Assessment of the Group in the Gulf of Mexico 56 3.4 Explanation of Checklist 57 3.5 Acknowledgements 60 3.6 References 61 3.7 Gulf of Mexico Checklist 66 3.8 Taxonomic Summary for Cephalopods of the Gulf of Mexico 73 CHAPTER 4. FIRST RECORDS OF Asperoteuthis acanthoderma (Lu, 1977) (CEPHALOPODA: OEGOPSIDA: CHIROTEUTHIDAE) FROM THE NORTH ATLANTIC OCEAN; STRAITS OF FLORIDA 74 4.1 Abstract 74 4.2 Introduction 75 4.3 Systematics 76 4.4 Description 76 4.5 Discussion 81 4.6 Acknowledgements 86 4.7 References 87 4.8 Figure Legends 88 CHAPTER 5. CONCLUSIONS 94 5.1 Summary 94 5.2 References 100 APPENDICES 102 Appendix A: Regional distribution point coordinates 103 Appendix B: Species richness comparison quadrats 104 Appendix C: Cephalopod distribution maps 105 ABOUT THE AUTHOR End page ii LIST OF TABLES Table 2.1 Regional cephalopod locations 20 Table 2.2 Region, species number and sample number for hotspots 33 Table 2.3 Cephalopod range extensions to Broad Caribbean 35 Table 3.1 Checklist of the Cephalopods of the Gulf of Mexico 66 Table 3.2 Taxonomic summary for cephalopods of the Gulf of Mexico 73 Table 4.1 Measurements of Asperoteuthis acanthoderma specimens 89 Table 5.1 Gulf of Mexico checklist species not included in Ch. II 95 iii LIST OF FIGURES Figure 1.1 Current flow through the Caribbean Sea and Gulf of Mexico 2 Figure 1.2 A summary of the role of cephalopods in the world’s oceans 6 Figure 1.3 Study Area 9 Figure 2.1 Current flow through the Caribbean Sea and Gulf of Mexico 17 Figure 2.2 Study area 24 Figure 2.3 Species richness per 5˚ latitudinal band 30 Figure 2.4 Comparison of species richness and number of individuals 30 Figure 2.5 Rapoport’s Rule- Rarefaction curve 31 Figure 2.6 Rapoport’s Rule- Chao 1 estimator graph 31 Figure 2.7 Eight study sites for richness and diversity comparisons 32 Figure 2.8 Species richness regional comparison 32 Figure 2.9 Hotspot species observed- Rarefaction curve 33 Figure 2.10 Hotspot Chao 1 estimator of regional species richness 34 Figure 2.11 Broad Caribbean sample effort map 34 Figure 4.1 Key West Asperoteuthis acanthoderma specimen 91 Figure 4.2 Marathon Asperoteuthis acanthoderma specimen 92 Figure 4.3 Internal organs of the Key West specimen 93 iv CEPHALOPODS OF THE BROAD CARIBBEAN SEA: DISTRIBUTION, ABUNDANCE, AND ECOLOGICAL IMPORTANCE Heather L. Judkins ABSTRACT The Broad Caribbean region is defined as the Gulf of Mexico, and the coastal and marine areas of the Caribbean Sea, including the chain of islands forming the Greater and Lesser Antilles, Turks and Caicos, the Bahamas, and the gulf coasts of the United States, Central and South America (Stanley, 1995). The cephalopods of the Broad Caribbean were examined in terms of distribution, abundance, and ecological importance. A suite of 5190 preserved cephalopod specimens were identified and catalogued to produce regional maps of cephalopod distribution within the Broad Caribbean. Eighteen range extensions were noted for known species. Regional species richness was examined with respect to Rapoport’s Rule with an eye toward possible cephalopod hotspots in the region. Cephalopods of the Broad Caribbean within the latitudinal bands of 8˚N and 30˚N do not support Rapoport’s Rule as they exhibit increasing species richness with increasing latitude. Eight subareas were chosen to compare species richness. Regionally, species richness is patchy, with the largest concentration of cephalopods off the eastern Florida coast. Areas of the southern Caribbean Sea are in need of more samples for accurate assemblage counts and more meaningful comparisons with other Caribbean regions. Rarefaction curves were used to normalize the variously sized samples throughout the Broad Caribbean. A checklist of the Gulf of Mexico based on literature developed a picture for the northern regions of the Broad Caribbean. This checklist v provided an updated account of cephalopod species that were reported from smaller literature works. Lastly, the first observation in the North Atlantic Ocean of the deep-sea squid Asperoteuthis acanthoderma (family Chiroteuthidae) was described. The description is based on two nearly intact, but damaged, specimens that were found floating at the surface in the waters off Key West and Marathon, Florida in 2007. All previously known records are recorded from a few specimens scattered in the western Pacific Ocean. There is a need for increased sampling throughout the Broad Caribbean to explore the systematics, life histories, distribution patterns, and potential fisheries for this group of organisms. vi CHAPTER 1 INTRODUCTION Cephalopods of the Broad Caribbean have not been reviewed in recent years. The unique features, currents, and coastlines of the Gulf of Mexico, Caribbean and the Straits of Florida combine as a potentially unique ecotone for cephalopod distribution, abundance, and diversity. Work conducted by G. Voss (1956), C.F. Roper (1984), N. Voss (1998), M. Vecchione (2002), and others provide background for further exploration of cephalopods in this area. The present study focuses on over 5000 specimens collected from the area to extend cephalopod research. 1.1 The Broad Caribbean The Broad Caribbean region is defined as the Gulf of Mexico, and the coastal and marine areas of the Caribbean Sea, including the chain of islands forming the Greater and Lesser Antilles, Turks and Caicos, the Bahamas, and the Gulf coasts of North, Central and South America (Stanley, 1995). The region is influenced by waters that flow through the lower Caribbean islands, originating from the Guiana Current that moves north along Brazil’s coast. The Guiana Current is joined by the North Equatorial Current, which flows through the lower Caribbean, veering north around western Cuba and into the Gulf of Mexico. Some upwelling occurs along the southern region of the Caribbean Sea (Longhurst, 1998). The majority of the flow moves around the Gulf coasts of the United States, flowing down along the west Florida coast before moving through the Straits of Florida to become the 1 Gulf Stream which moves northward through the Bahamas and along the eastern coast of Florida. The general movement of currents in the Broad Caribbean is from east to west with gyres often spinning off the main water flow (Stanley, 1995). Fig 1.1: Major currents of Broad Caribbean (from Carpenter et al. 2002) The surface temperature of the ocean in the tropical half of the Broad Caribbean region is averages 27˚C with little variation throughout the year.