THE MAINTENANCE OF MALE COLOUR POLYMORPHISM IN TELMA THERINA SARASINORUM, AN ENDEMIC FISH FROM LAKE MATANO, SULAWESI Suzanne Marie Gray MSc. University of Guelph, 2002 B.Sc. University of Guelph, 1999 THESIS SUBMITTED IN THE PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY In the Department of Biological Sciences O Suzanne Marie Gray 2007 SIMON FRASER UNIVERSITY Spring 2007 All rights reserved. This work may not be reproduced in whole or in part, by photocopy or other means, without permission of the author APPROVAL Name: Suzanne Marie Gray Degree: Doctor of Philosophy Title of Thesis: The maintenance of male colour polymorphism in Telmatherina sarasinorum, an endemic fish from Lake Matano, Sulawesi Examining Committee: Chair: Dr. J.M. Webster, Professor Emeritus -- Dr. L.M. Dill, Professor, Senior Supervisor Department of Biological Sciences, S.F.U. Dr. J.S. McKinnon, Professor Department of Biological Sciences. University of Wisconsin-Whitewater Dr. F. Breden, Associate Professor Department of Biological Sciences, S.F.U. Dr. B.J. Crespi, Professor Department of Biological Sciences, S.F.U. - - Dr. J.D. ~T~nolds,Professor Department of Biological Sciences, S.F.U. Public Examiner Dr. F.H. Rodd, Associate Professor Department of Zoology, University of Toronto External Examiner 22007 -- Date Approved .. I1 1%: SIMON FRASER &<$*Q ",,,,Idi brary DECLARATION OF PARTIAL COPYRIGHT LICENCE The author, whose copyright is declared on the title page of this work, has granted to Simon Fraser University the right to lend this thesis, project or extended essay to users of the Simon Fraser University Library, and to make partial or single copies only for such users or in response to a request from the library of any other university, or other educational institution, on its own behalf or for one of its users. The author has further granted permission to Simon Fraser University to keep or make a digital copy for use in its circulating collection (currently available to the public at the "Institutional Repository" link of the SFU Library website <www.lib.sfu.ca> at: <http:llir.lib.sfu.calhandlell8921112~)and, without changing the content, to translate the thesislproject or extended essays, if technically possible, to any medium or format for the purpose of preservation of the digital work. The author has further agreed that permission for multiple copying of this work for scholarly purposes may be granted by either the author or the Dean of Graduate Studies. It is understood that copying or publication of this work for financial gain shall not be allowed without the author's written permission. Permission for public performance, or limited permission for private scholarly use, of any multimedia materials forming part of this work, may have been granted by the author. This information may be found on the separately catalogued multimedia material and in the signed Partial Copyright Licence. The original Partial Copyright Licence attesting to these terms, and signed by this author, may be found in the original bound copy of this work, retained in the Simon Fraser University Archive. Simon Fraser University Library Burnaby, BC, Canada Revised: Spring 2007 a::.: SIMON FRASER .,?.. - .. <-? r.- .,A.,, UNlvERslnI ibra ry STATEMENT OF ETHICS APPROVAL The author, whose name appears on the title page of this work, has obtained, for the research described in this work, either: (a) Human research ethics approval from the Simon Fraser University Office of Research Ethics, (b) Advance approval of the animal care protocol from the University Animal Care Committee of Simon Fraser University: or has conducted the research (c) as a co-investigator, in a research project approved in advance, (d) as a member of a course approved in advance for minimal risk human research, by the Office of Research Ethics. A copy of the approval letter has been filed at the Theses Office of the University Library at the time of submission of this thesis or project. The original application for approval and letter of approval are filed with the relevant offices. Inquiries may be directed to those authorities, Simon Fraser University Library Burnaby, BC, Canada ABSTRACT Colour polymorphism has historically been used to understand the mechanisms that help to generate within- and between-species diversity. In a broad review of the literature I explored selective processes that contribute to the maintenance of colour polymorphism and may also lead to speciation. Frequency-dependent selection within, and divergent selection between populations, coupled with environmental heterogeneity appear to be important in promoting colour polymorphism. Using Telmatlwrinrr sar*asirior.zrrw,a small fish endemic to Lake Matano, Sulawesi, Indonesia, I tested the hypothesis that selection varies in a spatially heterogeneous light environment, resulting in the maintenance of variation in male colour. A comparative description of the mating behaviour of seven colour polymorphic telmatherinids from the Malili Lakes (including Matano), for which no behavioural ecology was known, suggests both conservation of reproductive behaviours and adaptations to different environments. The focal species, T. sar.asinorzrm, has five male colour morphs found in varying frequencies in two spawning habitats: shallow beach sites and deeper sites with overhanging roots. Measurements of the light environment and morph colour in each habitat indicate that blue males are more conspicuous in shallow habitats whereas yellow males are more conspicuous in root sites. I used a model to test if the most conspicuous morph in each habitat had the highest reproductive fitness based on a set of variables derived from extensive behavioural observations in the field. Males that contrast more with the background are expected to have higher pairing and spawning success with females, but may also be cuckolded or have their eggs cannibalized more often (there is a positive relationship between the number of cuckolders at a spawning event and egg cannibalism). In a comparison of the two most abundant morphs, blue males are more frequent and have higher fitness than yellow males in beach sites, and yellow males are predominant and have higher fitness in root sites. This suggests a role for environment-contingent sexual selection in promoting male colour polymoi-phism in this species. This research will help us to understand the processes that maintain diversity and provide insight into how protection of the heterogeneous visual environment should be directed. Keywords: sexual selection, Telmatherinidae, colour polymorphism, mating behaviour, cannibalism, cuckoldry, vision, environmental heterogeneity ACKNOWLEDGEMENTS The process that culminates in a finished thesis is an arduous, albeit rewarding, road that one does not travel alone. There are many people to whom 1 owe great thanks for their continuing support through the adventurous path that I like to call my thesis. Family, friends, mentors, perfect strangers, wild animals and a few inanimate objects added to the experience. To all of you, thank you. First, 1 would like to sincerely thank my senior supervisor, Larry Dill. Larry, you have been a true mentor, your door was always open and for that 1 thank you. Your advice on subjects scientific and academic have been honestly given and much appreciated. I hope to take your advice and the enthusiasm you share about behavioural ecology, and life in general, throughout my career. I would also like to thank my co-supervisor, Jeff McKinnon, for introducing me to the beautiful fishes of Lake Matano. Although almost all of our contact was via disembodied phone conversations and emails, I thank you for your continuous commitment to my work. The remainder of my advisory committee, Felix Breden, and Bernie Crespi, were instrumental in developing my ability to do research and to think through difficult research problems. Although not officially on my committee, Arne ~Mooersand Elizabeth Elle have always had open doors and made time to discuss the finer points of evolutionary theory, graduate school, and academia. I would also like to sincerely thank Helen Rodd and John Reynolds, who were on my examining committee, and who provided insightful comments on my thesis. During the course of almost every graduate degree there are those people acting behind the scenes that seem to prevent the world from collapsing. I would therefore like to thank Marlene Nguyen, for keeping me on track and registered, even when 1 was half a world away; Ian Gordon, for helping me actually get to the field with equipment and sanity intact; and, Dave Carmean, for keeping my computer from exploding. Doing fieldwork in a developing country adds a touch of adventure to any degree, and working in Indonesia was no exception. The Indonesian Science Foundation (LIPI) kindly provided permits to work in the Malili Lakes and Fadly Tantu provided assistance in the field. Fadly taught me a few things about life, not the least of which was patience. One of the first Indonesians I met upon arrival in Jakarta was Peter Hehanussa. His assistance in understanding the Indonesian system has been invaluable, and his kind- hearted nature was a wonderful welcome to Indonesia. Even though my work was conducted in a remote part of the world, Pt. Inco made my time there relatively luxurious. I would particularly like to thank Jim Gowans, Berno Wenzl, Sulvi Suardi, and Lili for facilitating my stays in Salonsa. I would also like to thank our boat drivers Wahab, Nus Allum, and Pak Dahlan. I would like to especially thank Dahlan for trying his best to teach me Indonesian with a smile on his face, even when I came up with such phrases as "Careful, there's a duck on your coconut!", instead of, "Careful, there's a bee on your head!". There were a number of people who made my visits to Sulawesi memorable, and in some cases life-changing. For her generosity, honesty, perpetual supply of Heineken, and for welcoming me into her home, I thank Tracie Fenato; for her excellent meals that always consisted of meat, I thank Kelly LeFroy; for reminding me that there is life beyond work, I thank the Soroako Hash House Harriers and a particular frog.