SEEING STARS: A MOLECULAR AND MORPHOLOGICAL INVESTIGATION OF THE ODONTASTERIDAE (ASTEROIDEA) by Alexis Michele Janosik A dissertation submitted to the Graduate Faculty of Auburn University in partial fulfillment of the requirements for the Degree of Doctor of Philosophy Auburn, Alabama August 4, 2012 Copyright 2012 by Alexis M. Janosik Approved by Kenneth M. Halanych, Chair, Professor of Biology Jonathan Armbruster, Professor of Biology Scott R. Santos, Associate Professor of Biology Abstract Odontasterids (Asteroidea: Echinodermata) comprise a clade described by A.E. Verrill in 1899 and are placed within Valvatida, a derived assemblage of sea stars. Boasting a worldwide distribution, Odontasterids are found in the Southern, Atlantic, and Pacific Oceans, with a concentration in cold-water habitats, in high latitudes in the Southern Hemisphere. Most of species of Odontasteridae are from the lower shelf and upper bathyal region, though some have been collected in the tidal zone. Odontasteridae includes the following genera: Acodontaster, Diabocilla, Diplodontias, Eurygonias, Hoplaster, and Odontaster, which are typically characterized by two series of equal, opposite and usually conspicuous marginal plates without intermarginal channels. They also usually possess triangular mouths and two rows of tubefeet with suckers. This group of organisms occupies an important role in marine environments and is important to the understanding of marine systems. To date, the phylogenetic and evolutionary history within the Odontasteridae has not been rigorously examined. Here, a comprehensively sampled molecular and morphological phylogenetic analysis of the Odontasteridae to assess interrelationships among and between genera is presented. More specifically, the recent evolutionary history of the genus Odontaster throughout the Western Antarctic waters and on the South American shelf is examined. The mitochondrial 16S ribosomal and cytochrome c oxidase subunit I (COI) genes were sequenced from adult and larval specimens. Finally, at a finer scale, high resolution genetic markers (microsatellites) are used to look at the circumpolar population structure of Odontaster validus. ii Acknowledgements I would like to sincerely thank my adviser Dr. Ken Halanych for his guidance, support, and friendship during my graduate studies at Auburn University. Thank you for encouraging me and pushing me to grow as a researcher and independent thinker. I would also like to thank my committee members for their contribution and good-natured support: Dr. Scott Santos, who provided careful and thoughtful mentorship, and Dr. Jon Armbruster, who provided valuable feedback and suggestions throughout the course of this work. Additionally, I am thankful for my outside reader, Dr. Eric Peatman for the time and input he devoted to my dissertation. A number of individuals provided samples used in this dissertation, and I am grateful for their willingness to share and collect samples on my behalf. I would also like to thank Dr. Carol Johnston for her unending support, encouragement, and friendship. She has been an incredible role model and the tremendous amount I have learned from her in all aspects of my life is truly invaluable. And, to my little buddies Grace and Abbey, thank you for your love and for always making me smile. To the past and present members of the Halanych/ Santos lab, thank you for your friendship and intellectual support. I could not have made it through this with out you! I would like to thank all good friends I have made throughout my time in Auburn. I am grateful for their support, shared fun times, and coffee breaks to the Gnu’s room. iii I would like to thank my mom, dad, sister and brother, for supporting me throughout my entire education. Special gratitude goes to my parents, Mark and Deb. Thank you for you unwavering faith and confidence in my abilities and for encouraging me to follow my dreams. Last, but certainly not least, I’d like to thank Brad. Thank you for your love, support, and encouragement. I could not have made it through this without you. iv Table of Contents Abstract ........................................................................................................................................... ii Acknowledgments.......................................................................................................................... iii List of Figures ................................................................................................................................ ix List of Tables ................................................................................................................................ xii Chapter 1: Introduction to Dissertation ..........................................................................................1 1.1 General introduction and background on Antarctic biology, Asteroidea, taxonomic history of Odontasteridae ............................................................................1 1.2 Research Objectives .....................................................................................................5 1.3 References ....................................................................................................................7 Chapter 2: Combined morphological and molecular phylogeny of Odontasteridae ....................14 2.1 Abstract ......................................................................................................................14 2.2 Introduction ................................................................................................................14 2.3 Materials and methods ................................................................................................17 2.3.1 Specimen collection ............................................................................................17 2.3.2 Molecular data ....................................................................................................17 2.3.2 Morphological data .............................................................................................18 2.4 Results ........................................................................................................................20 2.4.1 Morphological character analysis if Odontasteridae ...........................................21 2.1.2 Systematics .........................................................................................................26 2.5 Discussion ..................................................................................................................27 v 2.5.1 Phylogeny ..........................................................................................................27 2.5.2 Morphological and taxonomic implications ......................................................29 2.5.3 Biogeographical implications ............................................................................32 2.6 References ..................................................................................................................32 2.7 Legend of illustrations ...............................................................................................37 2.8 Appendix 1: Matrix of morphological characters ......................................................50 2.9 Appendix 2: Bayesian inference topology for 16S sequence data ...............................51 2.10 Appendix 3: Bayesian inference topology for COI sequence data ............................52 2.11 Appendix 4: All morphological characters mapped on to Bayesian Inference tree ..53 Chapter 3: Unrecognized Antarctic biodiversity: a case study with Odontaster (Odontasteridae; Asteroidea) ....................................................................................................54 3.1 Synopsis ....................................................................................................................54 3.2 Introduction ................................................................................................................54 3.3 Geological Setting ......................................................................................................55 3.4 Biogeography and genetics .........................................................................................57 3.5 Cryptic versus unrecognized diversity .......................................................................59 3.6 Case study: Odontaster species .................................................................................60 3.7 Current and future directions .....................................................................................66 3.8 References 5 3.8 References ..................................................................................................................67 Chapter 4: Evolutionary history of Southern Ocean Odontaster sea star species (Odontasteridae; Asteroidea) .........................................................................................................83 4.1 Abstract .....................................................................................................................83 4.2 Introduction ................................................................................................................84 4.3 Materials and methods ...............................................................................................87 vi 4.3.1 Sampling and identification ................................................................................87 4.3.2 DNA extraction, PCR, and sequencing ...............................................................88 4.3.3 Analyses ..............................................................................................................89 4.4 Results ........................................................................................................................90 4.4.1 Population structure and genetic distances ..........................................................90 4.4.2 Phylogenetic relationships ..................................................................................92 4.4.3 Morphological characters ....................................................................................93 4.5 Discussion ..................................................................................................................93 4.5.1 Underestimated biodiversity of Odontaster .........................................................93 4.5.2 Phylogeography of Odontaster ...........................................................................95 4.6 References 5 4.6 References ..................................................................................................................99 Chapter 5: Exploring the population connectivity of Odontaster validus around the Southern Ocean using high-resolution molecular markers ...................................................116 5.1 Abstract ...................................................................................................................116 5.2 Introduction ..............................................................................................................116 5.3 Materials and methods .............................................................................................120 5.3.1 Sampling, collection localities, and DNA extraction .......................................120 5.3.2 Microsatellite primer development ..................................................................121 5.3.2 Microsatellite analyses .....................................................................................123 5.4 Results .......................................................................................................................124 5.5 Discussion ................................................................................................................126 5.5.1 Genetic homogeneity in Odontaster validus .....................................................126 5.5.2 Circumpolarity ..................................................................................................127 5.5.3 Conclusions .......................................................................................................129 vii 5.6 References ................................................................................................................130 Chapter 6: Conclusions ..............................................................................................................145 6.1 Conclusions ..............................................................................................................145 6.2 References ................................................................................................................149 Appendix: Larval identification by barcoding of the Antarctic sea star Labidiaster annulatus (Labidiasteridae: Asteroidea) with notes on life history ..............................................................152 viii List of Figures CHAPTER 1 Figure 1: Echinoderm phylogenetic scheme depicting feather stars as the basal lineage, diverging early from the common ancestor of all echinoderms, and that urchins and sea cucumbers are more closely related to each other than to other echinoderms. * includes Concentricycloidea ...........................................................................................................11 Figure 2: External features of a sea star. From Lambert, P. (1981) The Sea Stars of British Columbia. British Columbia Provincial Museum, Victoria...............................................11 Figure 3: Map of significant geographic localities in the Southern Ocean ....................................12 CHAPTER 2 Figure 1: Worldwide distribution of Odontasteridae. White dots indicate known collection localities .............................................................................................................................27 Figure 2: Characteristic hyaline-tipped recurved spines surrounding the mouth. A. single recurved spine at jaw apex, B. double recurved spines at jaw apex, C. spines of Odontaster nov. sp. ............................................................................................................28 Figure 3: Plate I: aboral view. A. Acodontaster marginatus, B. Acodontaster elongatus, C. Acodontaster capitatus, D. Acodontaster conspicuus, E. Eurygonias hyalacanthus, F. Hoplaster kupe. ............................................................................................................…..29 Figure 4: Plate II: aboral view of Diplodontias species. A. Diplodontias dilatatus, B. Diplodontias singularis, C. Diplodontias robustus, D. Diplodontias miliaris. .................30 Figure 5: Plate III: aboral view of Odontaster species. A. Odontaster benhami, B. Odontaster crassus, C. Odontaster hispidus, D. Odontaster aucklandensis, E. Odontaster sp. (Galapagos), F. Odontaster meridionalis...........................................................................31 Figure 6: Plate IV: aboral view of Odontaster species. A. Odontaster setosus, B. Odontaster validus, C. Odontaster robustus, D. Odontaster rosagemmae, E. Odontaster penicillatus, F. Odontaster roseus. .........................................................................................................32 ix Figure 7: Bayesian inference topology for combined 16S and COI sequence data. Analysis details are provided in text. Number next to node indicates Bayesian posterior probabilities........................................................................................................................33 Figure 8: Bayesian inference topology for combined 18S sequence data. Analysis details are provided in text. Number next to node indicates Bayesian posterior probabilities. ..........33 CHAPTER 3 Figure 1: Odontaster morphology. Aboral, oral, and close-up of aboral side are pictured, respectively for: (a) Odontaster meridionalis, (b) Odontaster penicillatus, (c) Odontaster validus, (d) Odontaster roseus nov. sp., (e) Odontaster pearsei nov. sp. ..........................80 Figure 2: Photograph of the spine morphology of Odontaster. Spine on paxillae are pictured for: (a) Odontaster meridionalis, (b) Odontaster penicillatus, (c) Odontaster validus, (d) Odontaster roseus nov. sp., (e) Odontaster pearsei nov. sp. .............................................81 Figure 3: Drawing of the spine morphology of Odontaster. Spine on paxillae are pictured for: (a) Odontaster meridionalis, (b) Odontaster penicillatus, (c) Odontaster validus, (d) Odontaster roseus nov. sp., (e) Odontaster pearsei nov. sp.. ............................................82 CHAPTER 4 Figure 1: Map showing collection localities for Odontaster from South American and Antarctic waters, P denotes larval station locality (see picture insert). ...........................................110 Figure 2: Network representation for 16S and COI combined data. Networks are coded by geographic locality. Haplotypes are sized according to abundance and missing haplotypes are denoted by small, closed circles. Rectangles denote presumed ancestral haplotypes ........................................................................................................................111 Figure 3: Bayesian inference topology for combined 16S and COI data of South American, sub- Antarctic, and Antarctic Odontaster spp. Analysis details are given in the text. Number next to nodes indicates Bayesian posterior probabilities. Alphanumeric names correspond to individual numbers from Table 1. Tree rooted with Acodontaster conspicuus ........................................................................................................................112 Online Resource 1: Network representation for 16S data ..........................................................113 Online Resource 2: Network representation for COI data ..........................................................114 CHAPTER 5 Figure 1: Sampling stations for O. validus ..................................................................................142 Figure 2: Plot of likelihood (lnPr (D|K) of the genotype dataset for a given number of x