Regulation of fish fecundity types in changing environments: the case of species of the genus Alosa Doctoral dissertation Foivos Alexandros Mouchlianitis Aristotle University of Thessaloniki Faculty of Science School of Biology Department of Zoology Laboratory of Ichthyology Doctoral dissertation Regulation of fish fecundity types in changing environments: the case of species of the genus Alosa FOIVOS ALEXANDROS MOUCHLIANITIS Biologist Thessaloniki 2020 Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης Σχολή Θετικών Επιστημών Τμήμα Βιολογίας Τομέας Ζωολογίας Εργαστήριο Ιχθυολογίας Διδακτορική διατριβή Ρύθμιση του προτύπου γονιμότητας των ψαριών σε μεταβαλλόμενα περιβάλλοντα: η περίπτωση των ειδών του γένους Alosa ΦΟΙΒΟΣ ΑΛΕΞΑΝΔΡΟΣ ΜΟΥΧΛΙΑΝΙΤΗΣ Βιολόγος Θεσσαλονίκη 2020 The approval of this dissertation by the School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki does not imply acceptance of the author's opinions according to Law 5343/1932, article 202, paragraph 1. Η έγκριση της παρούσας διατριβής από το Τμήμα Βιολογίας της Σχολής Θετικών Επιστημών του Αριστοτελείου Πανεπιστημίου Θεσσαλονίκης δεν υποδηλώνει αποδοχή των γνωμών του συγγραφέως, σύμφωνα με τον Ν. 5343/1932, άρθρο 202, παράγραφος 1. I hereby certify that I am the author of this dissertation and that I have cited or referenced, explicitly and specifically, all sources from which I have used data, ideas, suggestions or words, whether they are precise quotes (in the original or translated) or paraphrased. Βεβαιώνω ότι είμαι ο συγγραφέας της παρούσας εργασίας και ότι έχω αναφέρει ή παραπέμψει σε αυτήν, ρητά και συγκεκριμένα, όλες τις πηγές από τις οποίες έκανα χρήση δεδομένων, ιδεών, προτάσεων ή λέξεων, είτε αυτές μεταφέρονται επακριβώς (στο πρωτότυπο ή μεταφρασμένες) είτε παραφρασμένες. Copyright: © Foivos Alexandros Mouchlianitis 2020. This is an open access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Cite this dissertation as follows: Mouchlianitis FA (2020). Regulation of fish fecundity types in changing environments: the case of species of the genus Alosa. Doctoral dissertation. Laboratory of Ichthyology, Department of Zoology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece Research funding: My research work was supported by the Hellenic Foundation for Research and Innovation (HFRI) and the General Secretariat for Research and Technology (GSRT), under the HFRI PhD Fellowship grant (GA. No. 493584). Advisory committee: Dr. Ganias Konstantinos, Associate Professor, School of Biology, Department of Zoology, Aristotle University of Thessaloniki, Greece Dr. Schultz Eric, Professor, Department of Ecology and Evolutionary Biology, University of Connecticut, US Dr. Antonopoulou Efthimia, Associate Professor, School of Biology, Department of Zoology, Aristotle University of Thessaloniki, Greece Examination committee: Dr. Kjesbu Olav Sigurd, Chief Scientist, Institute of Marine Research, Norway Dr. Somarakis Stylianos, Senior Researcher, Hellenic Centre for Marine Research, Greece Dr. Minos Giorgos, Associate Professor, Department of Nursing, International Hellenic University, Greece Dr. Bobori Dimitra, Associate Professor, School of Biology, Department of Zoology, Aristotle University of Thessaloniki, Greece Αφιερωμένο στον πατέρα μου, τον συμβουλάτορα και καθοδηγητή Table of contents List of abbreviations ....................................................................................................... i Glossary ........................................................................................................................ iii Summary ........................................................................................................................ v Περίληψη ..................................................................................................................... vii Acknowledgements ...................................................................................................... xi CHAPTER 1: Introduction .............................................................................................. 1 1.1 Genus Alosa ......................................................................................................... 1 1.2 Rationale behind Alosa sp. selection .................................................................. 5 1.3 Selected species ................................................................................................. 11 1.3.1 Alosa alosa .................................................................................................. 12 1.3.2 Alosa aestivalis ........................................................................................... 13 1.3.3 Alosa pseudoharengus ............................................................................... 14 1.3.4 Alosa macedonica ....................................................................................... 15 1.4 Aims and approach ............................................................................................ 15 CHAPTER 2: General methodology ............................................................................. 17 2.1 Sample processing ............................................................................................. 17 2.1.1 Histological process .................................................................................... 17 2.1.2 Whole-mount process ................................................................................. 18 2.3 Statistical analysis .............................................................................................. 20 CHAPTER 3: Role of oogonia, SG recruitment and SG oocyte production prior to the onset of spawning activity in a semelparous anadromous fish ................................ 21 3.1 Specific objectives ............................................................................................. 21 3.2 Specific methodology ........................................................................................ 21 3.3 Results ................................................................................................................ 23 3.4 Discussion .......................................................................................................... 28 CHAPTER 4: SG recruitment and SG phase of oogenesis during the spawning season of an iteroparous anadromous fish ............................................................................ 32 4.1 Specific objectives ............................................................................................. 32 4.2 Specific methodology ........................................................................................ 32 4.3 Results ................................................................................................................ 35 4.4 Discussion .......................................................................................................... 46 CHAPTER 5: Influence of life-history form on SG recruitment, SG phase of oogenesis and aspects of the spawning season .......................................................................... 49 5.1 Specific objectives ............................................................................................. 49 5.2 Specific methodology ........................................................................................ 49 5.3 Results ................................................................................................................ 52 5.4 Discussion .......................................................................................................... 56 CHAPTER 6: SG recruitment and SG phase of oogenesis within the ovulatory cycle of a landlocked iteroparous fish ................................................................................. 62 6.1 Specific objectives ............................................................................................. 62 6.2 Specific methodology ........................................................................................ 62 6.3 Results ................................................................................................................ 64 6.3.1 Ovulatory phases classification .................................................................. 64 6.3.2 Ovarian dynamics cyclicity ......................................................................... 67 6.3.3 Fecundity type and timing of SG Recruitment ........................................... 71 6.4 Discussion .......................................................................................................... 73 CHAPTER 7: General discussion and conclusions ....................................................... 75 Literature cited ............................................................................................................ 85 Annexes ..................................................................................................................... 109 Annex 1 .................................................................................................................. 109 Annex 2 .................................................................................................................. 110 Annex 3 .................................................................................................................. 111 Annex 4 .................................................................................................................