\- ECOLOGICAL PATTERNS IN THE DEVELOPMENT, SETTLEMENT AND RECRUITMENT OF ARCHAEOGASTROPODS FROM THE OREGON COAST by MATTHEW CURRY KAY A THESIS Presented to the Department of Biology and the Graduate School ofthe University of Oregon in partial fulfillment ofthe requirements for the degree of Master of Science March 2001 11 "Ecological Patterns in the Development, Settlement and Recruitment of Archaeogastropods from the Oregon Coast", a thesis prepared by Matthew C. Kay in partial fulfillment ofthe requirements for the Master of Science degree in the Department ofBiology. This thesis has been approved and accepted by: Dr. Richard B. Emlet, Chair ofthe Examining Committee Date Committee in charge: Dr. Richard B. Emiet Dr. Jan Hodder Dr. Alan L. Shanks Dr. Stephen S. Rumrill Accepted by: Vice Provost and Dean ofthe Graduate School III An Abstract ofthe Thesis of Matthew Curry Kay for the degree of Master of Sceince In the Department ofBiology to be taken March 2001 Title: ECOLOGICAL PATTERNS IN THE DEVELOPMENT, SETTLEMENT AND RECRUITMENT OF ARCHAEOGASTROPODS FROM THE OREGON COAST Approved: _ Dr. Richard B. Emlet Larvae ofthe limpets Lottia digitalis and LOffia asmi, as well as larvae ofthe flat abalone Halioits walallensis. develop into lecithotrophic veliger larvae and settle into benthic habitat after a breif planktonic stage. Larvae of1. digitalis settled and metamorphosed upon rocky substrata, as well as the barnacle P. polymerus, collected from an adult habitat high in the rocky intertidal. In contrast, substrata from mid and low intertidal zones failed to induce settlement and metamorphosis in larvae ofL. digitalis. These results suggest that recruitment into high intertidal habitat is driven by settlement rather than post settlement processes. New recruits within an adult habitat were most abundant low within the adult range and upon north-facing slopes ofrocks. Larvae ofH walallensis that experienced a five-day extension oftheir competence period exhibited accelerated rates ofmetamorphosis, as well as accelerated juvenile growth rates, relative to larvae that were presented with settlement surfaces at initial competence. IV CURRICULUM VITA NAME OF AUTHOR: Matthew Curry Kay PLACE OF BIRTH: Santa Barbara, California DATE OF BIRTH: January 29, 1973 GRADUATE AND UNDERGRADUATE SCHOOLS ATTENDED: University of Oregon Universidad San Francisco de Quito (Quito, Ecuador) DEGREES AWARDED: Master of Science in Biology, 2001, University of Oregon Bachelor of Science in Biology, 1996, University of Oregon AREAS OF SPECIAL INTEREST: Natural History ofCoastal Marine Invertebrates Reproductive Biology and Ecology of Marine Gastropods PROFESSIONAL EXPERIENCE: Graduate Teaching Fellow, Oregon Institute of Marine Biology (University of Oregon), Charleston, 1998-2000 Undergraduate Teaching Assistant, Department of Biology, University of Oregon, Eugene: Fall 1993, Fall 1995, Winter 1995 AWARDS AND HONORS: Neil Richmond Memorial Fellow, 2000 Conchologists ofAmerica Student Research Award, 1999 v GRANTS: Western Society of Malacologists Student Research Grant, 1999 PADI: Project AWARE Research Grant, 1999 VI ACKNOWLEDGEMENTS I am profoundly appreciative to Dr. Jan Hodder. This thesis would not exist, nor would it have been as enjoyable to complete, ifnot for her good will and generosity. I am equally appreciative to my advisor, Dr. Richard Emlet, for his expert advice and criticisms, as well as his personal interest in my professional development. Dr. Emlet has been an enthusiastic and supportive mentor, and his lessons will not soon be forgotten. I was honored to have Dr. Alan Shanks and Dr. Steve Rumrill serve on my committee. I have enjoyed the company of1. Schaeffer and the late N. Richmond, whether diving for flat abalone or discussing natural history. I am grateful to M. Berger, who offered assistance during a diving collection and (with equal willingness!) statistical analysis of data. A. PuIs made trips to the intertidal more insightful and enjoyable. B. Butler made forays into the OIMB library both productive and humorous. The facuIty and staffofthe Oregon Institute of Marine Biology were unwavering in their support ofresearch objectives. Financial support essential to this project was provided by NSF grant UFE-203221 to J. Hodder, by NSF grant OCE-9911682 to R. Emlet, and the following awards to M. Kay: Conchologists ofAmerica Student Research Award, Western Society of Malacologists Student Research Grant, and a grant from PADI: Project AWARE. Finally, I thank my parents Dr. 1.T. and G.c. Kay, whose waves ofaffection and support have shaped oceans of opportunity. \- Vll DEDICATION This thesis is dedicated, however inadequately, to the memory ofthe late Neil Richmond. Neil's premature death paradoxically served as a reiteration of life's most fundamental lesson: how to live. I am reminded ofNeil, and his love for life, when I read the following passage from John Steinbeck's "The Log From the Sea of Cortez". The following reflections were inspired as the Crew ofthe Western Flyer steamed south through rolling seas along the California coastline - a scene in which, no doubt, Neil would have glowed. "We sat on a crate oloranges and thought what good men most biologists are. the tenors olthe scientific world - temperamental... loud-laughing, and healthy. Once in a while one comes across the other kind - what used in the university to be called a "dry­ ball" - but such men are not really biologists. They are the embalmers ofthe field, the picklers who see only the preservedform oflife without any ofits principle. The true biologist deals with life, with teeming boisterous life, and learns somethingfrom it, learns that thefirst rule oflife is living... Your true biologist will sing you a song as loud and off-key as will a blacbmith... and meanwhile he is very good company... " For Neil: September 24, 1954 - June 8, 1999 VIII TABLE OF CONTENTS Chapter Page 1. GENERAL INTRODUCTION 1 II. SPAWNING, LARVAL DEVELOPMENT AND METAMORPHOSIS OF THE LIMPETS Iottia digitalis AND Iottia asmi (PATELLOGSTROPODA: LOTTIDAE) 5 Introduction " ,""" '" 5 Materials and Methods 7 Spawning and Gamete Collection 7 Larval Culture 8 Light and Scanning Electron Microscopy 9 Results 11 Spawning and Gamete Collection 11 Ioffia digitalis 11 Ioffia asmi 12 Larval Development 13 Discussion '" ,," 16 Spawning 16 Larval Development. 20 III. LABORATORY EVIDENCE THAT NATURAL RECRUITMENT IN THE LIMPET Iottia digitalis (PATELLOGASTROPODA: LOTTIDAE) IS DRIVEN BY SETTLEMENT RATHER THAN POST-SETTLEMENT PROCESSES 33 Introduction 33 Materials and Methods 36 Data Analysis 42 IX Results 43 Discussion 46 IV. ANOTHER ANGLE ON THE RECRUITMENT OF HIGH INTERTIDAL LIMPETS - THE CASE OF Lottia digitalis REVISITED 63 Introduction 63 Materials and Methods 65 Site Description 65 Observations 66 Identification and Enumeration of Small Individuals 67 Data Analysis 68 Results 69 Discussion 72 V. SPAWNING, LARVAL DEVELOPMENT AND THE EFFECT OF AN EXTENDED METAMORPHIC COMPETENCE PERIOD IN LARVAE OF THE FLAT ABALONE, Haliotis walallensis STEARNS 81 Introduction 81 Materials and Methods 84 Collection and Spawning 84 Fertilization and Larval Culture 85 Extension of Competence Period Experiment. '" 86 Data Analysis 88 Results 89 Collection and Spawning 89 Early Development and Pigment Partitioning 90 Later Development. 92 Extension of Competence Period Experiment. 93 x Discussion 95 Spawning and Larval Development. 95 Extension of Competence Period Experiment. 97 VI. CONCLUDING SUMMARY 112 BIBLIOGRAPHy 114 Xl LIST OF FIGURES Figure Page 1. The Total Number ofEggs Released, Relative to Shell Length, For Indivdual Females of Lottia digitalis and Lottia asmi That Were Induced to Spawn in the Laboratory 24 2. Light Micrographs of Developmental Stages in Lottia asmi 25 3. Light Micrographs of Developmental Stages in Lottia digitalis 26 4. Scanning electron micrographs of: (A) Lottia digitalis larval shell in lateral view, rotated slightly to expose the shell aperature 27 5. Scanning electron micrographs of postlarval (A) Lottia digitalis and (B) Lottia asmi 28 6. Fates of larvae of Lottia digitalis 3 days (A) and 6 days (B) after introduction to field-collected settlement surfaces. These larvae are progeny of adults spawned on February 12, and were introduced to settlement surfaces on February 18 55 7. Fates of larvae ofLottia digitalis 3 days (A) and 6 days (B) after introduction to field-collected settlement surfaces. These larvae are progeny of adults spawned on March 2, and were introduced to settlement surfaces on March 8 56 8. Growth ofsibling Lottia digitalis postlarvae introduced to High/Adults and Mid/Adults substrata in the laboratory (see materials and methods for substrata descriptions) 57 9. Fates oflarvae ofLottia digitalis, from two different sets ofparents, 6 days after introduction to macroalgal settlement surfaces on March 8 (A) and March 12 (B) 58 10. Fates of Lottia digitalis larvae introduced to isolates ofthe High rock from adult habitat (see materials and methods for description of isolates) 59 Xll 11. A postlarval LOffia digitalis that metamorphosed in the presence of, and is actively feeding upon, the filamentous green alga (FGA) isolated from High rock collected in adult L. digitalis adult habitat 60 12. Fates of larvae of Lottia digitalis introduced to rock collected from adult habitat high in the intertidal (High Rock) and the stalked barnacle Pollicipes polymerus 61 13. Composite results for censuses ofLoUia digitalis from 25 different 0.25m2 quadrats within an adult habitat.