TAXONOMY AND ECOLOGY OF PREDATORY MARINE FLATWORMS (PLATYHELMINTHES: POLYCLADIDA) IN BOTANY BAY, NEW SOUTH WALES, AUSTRALIA by Ka-Man Lee A thesis submitted in fulfilment of the requirements for the degree of Master of Science by research University of New South Wales April 2006 ORIGINALITY STATEMENT ‘I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project’s design and conception or in style, presentation and linguistic expression is acknowledged.’ Signed Ka-Man Lee April 2006 II ACKNOWLEDGEMENTS Without the encouragement and enthusiasm of my supervisor, Dr. Emma Johnston, this thesis would not have been possible. Thank you for allowing me to pursue some innovative experiments and for your inspiration and criticism along the way. I thoroughly appreciated your patience and guidance. I am eternally grateful to my co-supervisors, Assoc. Prof A. Michel Beal and Dr. Alistair Poore. Assoc. Prof Michel Beal has been incredibly supportive and generous with his time. I thoroughly enjoyed and appreciated your endless supply of patience and guidance. I enjoyed listening to your sharing. Thanks for visiting me in the dark room when I was doing the tedious observation work. I am also truly indebted to Dr. Alistair Poore who has helped me so much throughout my study. Thanks for telling me you are always there and willing to help whenever I need. Thanks for giving me the opportunity to gain the experience in demonstration. I really appreciate that. I would especially like to acknowledge Professor John Hodgkiss for his professional advice and critical comment on the manuscripts and earlier drafts of my thesis. Thank you for your inspiration for scientific research. You are my constant source of encouragement and support. Identification of the fabulous marine flatworms would not have been possible without the guidance from Dr. Leslie Newman at the Auckland Museum. Thanks for your endless support and advice in identifying and preserving the polyclads. I would also like to acknowledge the help of Gavin McKenzie at the Histology and Microscopy Unit at University of New South Wales for the preparation of whole mount specimens. Many people from the Johnston and Poore Lab provided me with professional advice in the fields of experimental setup, statistical analysis and writing. I would like to thank the following in order of appearance: Graeme Clark, Richard Piola, Keyne Monro, Dave Roberts, Nicole Hill, Bronwyn Combo and Candida Barclay. In particular, thank you to Richard Piola for his assistance in the laboratory experimental setup on weekends. I am grateful to the people from the workshop in the School of Biological, Earth and Environmental Sciences (School of BEES), John Matossian, Peter Boormian, and Ross Vickery, for their assistance in solving the technical problems. They are of great help in drilling holes and making windows on the experimental apparatuses whenever I need. III I would like to acknowledge the help of Stephanine Poon, Titus Kwok and Chris Wong for their assistance in collecting seawater during weekends and holidays. Special thank is given to Carmen Lee who provided me with expert advice on the use of computer software and photo-taking. Lee Ann Rollins, Candida Barclay, Nicole Hill, Keyne Monro, Richard Piola and Kelly Wright have provided me with valuable advice and endless care in the past two years. Thanks for your friendship and support. I am grateful to my friends who are miles away from me, but provide me constant support and love throughout my study. In particular, I would like to thank Dr. J-D Gu, Dr. Billy Hau, Jessie Lai, Jennifer Wong, Carmen Woo and Ida Yu. Thanks for encouraging me when my plates disappeared in the sea. To my family, thank you for always encouraging me. Without your love and support, there is no way possible that I would have been able to undertake this project. I would like to thank my parents and grandparents who provide endless support and love even though I am away from home throughout my study. I sincerely thank for your encouragement and tolerance to my bad temper. May all the glory and honour be unto God, the Creator of all things. Amen. IV TABLE OF CONTENTS Originality statement II Acknowledgements III Table of Contents V List of tables VIII List of figures IX Abstract XII CHAPTER 1: GENERAL INTRODUCTION 1.1 Overview 1 1.2 Taxonomy of marine flatworms 1 1.3 Reproduction and parental care 3 1.4 Food and predation 4 1.5 Ecotoxicology 5 1.6 Research aims 7 1.6.1 Thesis structure 7 CHAPTER 2: DESCRIPTION OF A NEW PREDATORY FLATWORM (PLATYHELMINTHES, POLYCLADIDA) FROM BOTANY BAY, NEW SOUTH WALES, AUSTRALIA 2.1 Abstract 8 2.2 Introduction 9 2.3 Materials and methods 10 2.3.1 Specimen collection 10 2.3.2 Specimen processing 10 2.3.3 Predatory behaviour 12 2.4 Results 13 2.4.1 Systematics 13 2.4.2 Biology 18 2.4.3 Ecology: Predatory behaviour and feeding rate 18 2.5 Discussion 20 V CHAPTER 3: ROLE OF BROODING IN HATCHING SUCCESS OF ECHINOPLANA CELERRIMA AND STYLOCHUS PYGMAEUS (PLATYHELMINTHES: POLYCLADIDA) EGGS 3.1 Abstract 22 3.2 Introduction 23 3.3 Materials and methods 26 3.3.1 Study site 26 3.3.2 Specimen collection 26 3.3.3 Experimental design 27 3.3.4 Data analysis 32 3.4 Results 34 3.4.1 Interspecific differences in brooding behaviour 34 3.4.2 Effects of brooding on the hatching success of Echinoplana 34 celerrima and Stylochus pygmaeus eggs 3.4.3 Changes in the proportion of brooding time of Echinoplana 35 celerrima in the presence of potential flatworm egg predators 3.4.4 Significance of brooding to the hatching success of 35 Echinoplana celerrima eggs in the presence of potential flatworm egg predators 3.4.5 Size of flatworms 36 3.5 Discussion 43 CHAPTER 4: LOW LEVELS OF METAL POLLUTION AFFECT REPRODUCTIVE SUCCESS OF A MOBILE INVERTEBRATE 4.1 Abstract 47 4.2 Introduction 48 4.3 Materials and methods 52 4.3.1 Study site 52 4.3.2 Collection of flatworms and barnacles 52 4.3.3 Copper treatments 53 4.3.4 Experimental design 54 4.3.5 Data analysis 58 4.4 Results 59 4.4.1 Predation rate of Stylochus pygmaeus 59 4.4.2 Response of Stylochus pygmaeus to physical stimulation 59 VI 4.4.3 Reproductive success of flatworms 59 4.4.4 Feeding rate of Balanus variegatus 60 4.4.5 Size of barnacles and flatworms 60 4.4.6 Chemical analysis 61 4.5 Discussion 68 4.5.1 Predation rate of Stylochus pygmaeus 68 4.5.2 Reproductive success of Stylochus pygmaeus 70 4.5.3 Effects of Stylochus pygmaeus on the feeding rate of Balanus 71 variegatus 4.6 Conclusion 73 CHAPTER 5: SUMMARY AND IMPLICATIONS 5.1 Marine flatworm diversity 74 5.2 Reproductive behaviour of marine flatworms 75 5.3 Predatory behaviour of marine flatworms 76 5.4 Implications of sublethal effects of copper 77 5.5 Conclusion 77 CITED REFERENCES 78 APPENDIX: MARINE FLATWORM DIVERSITY AT KURNELL 95 PIER, BOTANY BAY, NEW SOUTH WALES, AUSTRALIA VII LIST OF TABLES Table 3.1 Summary of two-factor ANOVA of the hatching success and the 37 time taken for the Echinoplana celerrima eggs to finish hatching in the presence and absence of Morula marginalba, Bedeva hanleyi and Stylochus pygmaeus with and without the provision of parental care. Table 3.2 Summary of one-factor ANOVA of the proportion of time spent 38 brooding that Echinoplana celerrima spent in the presence of (a) Morula marginalba and (b) Bedeva hanleyi and Stylochus pygmaeus. P-value in bold indicate significant difference at Į = 0.050. Table 3.3 Summary of one factor ANOVA of the number of egg batches 39 that Echinoplana celerrima laid in the presence of (a) Morula marginalba and (b) Bedeva hanleyi and Stylochus pygmaeus. Table 4.1 Summary of two-factor ANOVA and planned comparisons on the feeding rate of barnacles in the presence and absence of flatworms 62 and copper in Experiments 1 and 3. All planned comparisons were tested against the error term for the main test of Cu treatments. P-values in bold indicates significant differences at Į = 0.050. Table 4.2 Nominal and measured copper concentrations (µg L-1) for copper treatments used in Experiment 1 & 2 indicate that the measured copper concentrations of the treatment solutions from the experiment 63 are close to their nominal values. Dashes represent copper concentrations not used in a particular experiment. Table A1 Key to distinguish between the flatworm species at Botany Bay. 99 Table A2 Prevalent sessile species listed in the order of abundance on 107 settlement plates. VIII LIST OF FIGURES Figure 2.1 Living Imogine lateotentare sp. nov. from Kurnell Pier, Botany 16 Bay, New South Wales, Australia: (a) colour pattern on dorsal surface and (b) ventral view showing pharynx, gonopores and vas deferens. Scale bar: 1.4 mm. Figure 2.2 Imogine lateotentare sp. nov. preserved: (a) Diagram of the 17 dorsal surface, (b) morphology of the ventral surface, (c) arrangement of the dorsal eyes, (d) diagrammatic reconstruction of the reproductive system (c - cerebral eyes, ce - cement glands, f - frontal eyes, fa - female antrum, go - gonopores, m - mouth, ma - male antrum, n - nuchal tentacle, p - penis papillae, ph - pharynx, pr - prostatic vesicle, s - seminal vesicle, va - vasa deferentia).