UNIVERSIDADE DE SÃO PAULO FFCLRP – DEPARTAMENTO DE BIOLOGIA PROGRAMA DE PÓS-GRADUAÇÃO EM BIOLOGIA COMPARADA “Colour polymorphism and its function in Hippolyte obliquimanus: camouflage and resource use diversification” “Polimorfismo de cor e sua função em Hippolyte obliquimanus: camuflagem e diversificação no uso de recursos” Rafael Campos Duarte Tese apresentada à Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da USP, como parte das exigências para a obtenção do título de Doutor em Ciências, Área: Biologia Comparada. RIBEIRÃO PRETO – SP 2017 UNIVERSIDADE DE SÃO PAULO FFCLRP – DEPARTAMENTO DE BIOLOGIA PROGRAMA DE PÓS-GRADUAÇÃO EM BIOLOGIA COMPARADA “Colour polymorphism and its function in Hippolyte obliquimanus: camouflage and resource use diversification” “Polimorfismo de cor e sua função em Hippolyte obliquimanus: camuflagem e diversificação no uso de recursos” Rafael Campos Duarte Orientador: Prof. Dr. Augusto Alberto Valero Flores Tese apresentada à Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da USP, como parte das exigências para a obtenção do título de Doutor em Ciências, Área: Biologia Comparada. RIBEIRÃO PRETO – SP 2017 Ficha catalográfica Duarte, Rafael Campos Colour polymorphism and its function in Hippolyte obliquimanus: camouflage and resource use diversification, 2017. 124 p. : il. ; 30 cm Tese apresentada à Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da USP, como parte das exigências para a obtenção do título de Doutor em Ciências, Área: Biologia Comparada. Orientador: Flores, Augusto Alberto Valero 1. Colour change. 2. Camouflage. 3. Habitat use. 4. Visual models. 5. Stable isotopes. 6. Trophic niche. “I may not have gone where I intended to go, but I think I have ended up where I needed to be.” Douglas Adams i ii SUMMARY OF CONTENTS ACKNOWLEDGEMENTS................................................................................................................. v ABSTRACT .................................................................................................................................... vii RESUMO ........................................................................................................................................ ix GENERAL INTRODUCTION .......................................................................................................... 11 Colour polymorphism, camouflage and habitat use ............................................................... 11 The biological model ............................................................................................................... 12 References ............................................................................................................................... 14 CHAPTER 1 .................................................................................................................................. 17 Camouflage through colour change: mechanisms, adaptive value, and ecological significance ............................................................................................................................. 18 Abstract ............................................................................................................................... 18 Introduction ........................................................................................................................ 19 Mechanisms and control of colour change ......................................................................... 20 Causes, consequences, and ecological implications of colour change for concealment .... 26 Concluding remarks and key future research ..................................................................... 32 Acknowledgements ............................................................................................................. 36 References ........................................................................................................................... 36 CHAPTER 2 .................................................................................................................................. 41 Shape, colour plasticity, and habitat use indicate morph-specific camouflage strategies in a marine shrimp......................................................................................................................... 42 Abstract ............................................................................................................................... 42 Introduction ........................................................................................................................ 44 Methods .............................................................................................................................. 49 Results ................................................................................................................................. 56 Discussion ............................................................................................................................ 62 Conclusions ......................................................................................................................... 67 iii Acknowledgements ............................................................................................................. 68 References ........................................................................................................................... 68 Additional Information ........................................................................................................ 75 CHAPTER 3 .................................................................................................................................. 77 The adaptive value of camouflage and colour change in a polymorphic shrimp................. 78 Main text ............................................................................................................................. 78 Methods .............................................................................................................................. 81 Acknowledgements ............................................................................................................. 89 References ........................................................................................................................... 89 Additional Information ........................................................................................................ 92 CHAPTER 4 .................................................................................................................................. 95 Habitat-dependent niche partitioning between colour morphs of the algal-dwelling shrimp Hippolyte obliquimanus ......................................................................................................... 96 Abstract ............................................................................................................................... 96 Introduction ........................................................................................................................ 98 Material and methods ....................................................................................................... 101 Results ............................................................................................................................... 104 Discussion .......................................................................................................................... 111 Acknowledgements ........................................................................................................... 115 References ......................................................................................................................... 115 Additional Information ...................................................................................................... 121 GENERAL CONCLUSIONS .......................................................................................................... 123 iv ACKNOWLEDGEMENTS I am very thankful to… My supervisor Augusto Flores for all his help and stimulus to transform me in a scientist who thinks and develops your questions before anything else. Thanks for your friendship, confidence and freedom that allowed me to develop new skills sometimes far from your research line. Your optimism and admiration for your work encourages me to persist in this crazy world of science! To the post-graduation program in Comparative Biology (FFCLRP-USP) for receiving me as a PhD student and to the secretary Vera for helping me in all administrative issues even though the distance. To Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) for the financial support provided by a regular PhD fellowship (#2012/17003-0) and a BEPE grant to develop my research abroad (#2015/ 04484-8). To my collaborator and supervisor in the UK, Martin Stevens, for receiving me so good in Cornwall and open my mind to a new world about animal camouflage, image analysis and Cornish life-style. Thanks for all the meetings and discussions in different pubs when we forgot the time while we were talking about the fascinating world of the colourful prawns! To Catarina Vinagre and Miguel Leal for their assistance with the stable isotopes work and for all the discussions regarding the Chapter 4 of this thesis. To Álvaro Migotto for teaching me about photography and video recordings and for helping me to get the nicest and awarded shrimp images ever! To all CEBIMar staff