Evolution of Brooding in Sea Anemones: Patterns, Structures, and Taxonomy DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Paul G. Larson Graduate Program in Evolution, Ecology and Organismal Biology The Ohio State University 2015 Dissertation Committee: Marymegan Daly, Advisor John Freudenstein Johannes Klompen Copyright by Paul G. Larson 2015 Abstract Brooding is an unusual reproductive behavior among Actiniarians (sea anemones). Sea anemones commonly free-spawn gametes producing pelagic offspring that develop independently. In brooding, offspring are retained until the juveniles or adult stage. Brooding behaviors are diverse among sea anemones but some of this diversity is obscured by imprecise or inconsistent terminology. Brooding is taxonomically widespread, but most brooding species are found within Actiniidae. The actiniid genus Epiactis is particularly notable for its wide geographic distribution and diversity in characters associated with reproduction. Individuals of the Antarctic, hermaphroditic species E. georgiana brood offspring on the surface of the adult, whereas anemones in the gonochoric north Pacific species, E. handi, hold offspring within the gastrovascular cavity. Additional Epiactis species have been described from the Arctic and Atlantic oceans and include species which aren’t known to brood. This variation provides an unusual opportunity to investigate the evolutionary patterns in reproductive characters and ramifications of brooding modes, but also calls into question the monophyly of the genus. This uncertainty is manifested in the literature through taxonomic actions including the creation of Cnidopus for several Epiactis species and in dispute regarding the specific identity of certain Epiactis specimens. ii Here I employ morphological and molecular techniques to investigate taxonomic and systematic questions about the genus Epiactis, and to investigate patterns in the evolution of brooding in sea anemones. I address taxonomic issues by employing anatomical methods such as histological sectioning, tissue squash preparations and dissection. I make extensive use of museum materials and examine type specimens and other museum lots of the focal species, and collect new specimens from across the known range in order to identify geographic and taxonomic boundaries. I use DNA sequence data to assess relationships among species and investigate the evolutionary patterns in brooding modes and and other reproductive characteristics. Chapter 1 introduces the group and biological phenomena of interest. In chapter 2 the phenomenon of brooding is reviewed broadly across Actiniaria. Terminology used in discussion of brooding is defined. Epiactis fecunda is treated in chapter 3 and is reassigned to the genus Urtcina based on morphological examination of new specimens. In chapter 4, new collections and museum specimens determined to be Epiactis ritteri and Epiactis japonica are examined. Their specific destinctness is justified with morphological characters, as is the distinctness of the internally brooding individuals from lower latitudes previously identified as E. ritteri. The latter individuals are renamed Epiactis handi. The final chapter reports on phylogenetic analyses of Epiactis species and other actiniids based on nucleotide sequence data. In it, Epiactis is revealed to be a polyphyletic group in which North Pacific species and Southern hemisphere species form separate clusters, both with internal and externally brooding representatives. In the North Pacific, externaly brooding species have evolved from internally brooding ancestors. iii This work is dedicated to my unfailingly supportive and understanding wife, Dawn, and to my daughter, Violet, whose intense curiosity and powers of observation never cease to amaze and inspire me. iv Acknowledgments Here I would like to acknowledge, first and foremost, my advisor, Dr. Marymegan Daly, who edits manuscripts quickly and is a strong and effective advocate for her current and former students throughout their time in her lab and beyond. Committee members Drs. John Freudenstein and Hans Klompen have kept my intellectual stomach full of food for thought through challenging courses and interesting lunchtime conversation. I thank the department of Evolution, Ecology, and Organismal Biology for financial support in the form of graduate teaching associateships and funding opportunities for travel to professional meetings. Lab mates (past and present) Dr. Estefanía Rodríguez, Dr. Annie Lindgren, Dr. Abby Reft, Dr. Luciana Gusmão, Esprit Heestand-Saucier, Jenny Wollschlager, Dr. Anthony D’Orazio, Jason Macrander, Ben Titus, Ieva Roznere, Nick Skomrock, and (honorary member) Brandon Sinn have all provided advice, help, inspiration, friendship, and, of course, commiseration in one form or another throughout my dissertation. Finally, I thank the people and funding sources that have helped me to accomplish the research presented here, who are listed by name in the relevant chapters. v Vita 2000................................................................Monticello High School 2000-2004 ......................................................B.S. Department of Ecology, Evolution, and Behavior, University of Minnesota 2008 to present ..............................................Graduate Teaching Associate, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University Publications In pressLarson P.G., and M. Daly Phylogenetic Analysis reveals an Evolutionary Transition from Internal to External brooding in Epiactis Verrill (Cnidaria: Anthozoa: Actiniaria) and rejects the validity of the genus Cnidopus Carlgren. Molecular Phylogenetics and Evolution. http://dx.doi.org/10.1016/j.ympev 2015.10.008 2015 Larson P.G., and M. Daly ‘Putting Names with Faces’; a description of Epiactis handi sp. nov. helps to resolve taxonomic confusion in species of the sea anemone Epiactis (Actiniaria, Actiniidae). Journal of the Marine Biological Association of the United Kingdom 95: 913-928. vi 2012 Larson P.G., J.-F. Hamel, and A. Mercier. Redescription and notes on the reproductive biology of the sea anemone Urticina fecunda (Verrill, 1899), comb. nov. (Cnidaria: Actiniaria: Actiniidae). Zootaxa 3523: 69–79. 2006 DaCosta, M., P. Larson, J.P. Donahue, and S. Weller Phylogeny of Milkweed Tussocks (Arctiidae: Arctiinae: Phaegopterini) and Its Implications for Evolution of Ultrasound Communication. Annals of the Entomological Society of America 99: 723-742. Fields of Study Major Field: Evolution, Ecology and Organismal Biology vii Table of Contents Abstract ............................................................................................................................... ii Acknowledgments............................................................................................................... v Vita ..................................................................................................................................... vi Publications ........................................................................................................................ vi Fields of Study .................................................................................................................. vii Table of Contents ............................................................................................................. viii List of Tables ..................................................................................................................... ix List of Figures ..................................................................................................................... x Chapter 1: Introduction to Sea Anemones, Brooding, and Epiactis .................................. 1 Chapter 2: A Review of Brooding in Actiniaria ................................................................. 7 Chapter 3: Identity of a putative Atlantic Epiactis species ............................................... 53 Chapter 4: Revision of North Pacific Epiactis species. .................................................... 73 Chapter 5: Evolution of Brooding in Epiactis ................................................................ 112 References ....................................................................................................................... 152 viii List of Tables Table 1 Brooding sea anemones and and characteristics .................................................. 13 Table 2 Cnidae of Urticina fecunda.................................................................................. 69 Table 3. Cnidae of Epiactis ritteri and E. handi. ............................................................ 989 Table 4 Epiactis species and reproductive traits ............................................................. 117 Table 5 New specimens collected for phylogenetic analysis.......................................... 120 Table 6 Taxa and sequences for phylogenetic analysis .................................................. 123 Table 7 Sequence and matrix lengths for each locus ...................................................... 137 ix List of Figures Figure 1 Sea anemone general anatomy ............................................................................. 2 Figure 2 Epiactis species in situ.......................................................................................... 6 Figure 3 Brooding pits in Epiactis