Macroscopic and microscopic description of snapper (Pagrus auratus) gonads from Shark Bay, Western Australia - Fisheries Research Report No. 184

.................................................................................................................. 1 1.0 Introduction ........................................................................................................... 2 2.0 Methods .................................................................................................................. 5 2.1 Collection of samples ...................................................................................... 5 2.2 Processing of samples ...................................................................................... 5 2.2.1 Gonad staging systems .......................................................................... 5 2.2.2 Batch fecundity ...................................................................................... 6 2.2.3 Staging of post-ovulatory follicles ....................................................... 7 2.2.4 Oocyte atresia ........................................................................................ 7 3.0 Results and Discussion .......................................................................................... 8 3.1 Macroscopic staging system ............................................................................ 8 3.1.1 Accuracy of macroscopic stages ........................................................... 8 3.1.2 Development of a more reliable macroscopic staging system .............. 10 3.2 Microscopic staging system ........................................................................... 12 3.3 Pictorial guide to staging P. auratus ovaries ................................................... 15 3.4 Improvement to estimates of batch fecundity using the more detailed microscopic staging system ............................................................................. 15 4.0 Conclusions ............................................................................................................ 18 5.0 Acknowledgements ................................................................................................ 19 6.0 References .............................................................................................................. 19 7.0 List of Plates ........................................................................................................... 21 8.0 Appendices ............................................................................................................. 28 Appendix 1 .............................................................................................................. 28 Appendix 2 .............................................................................................................. 29 Appendix 3 .............................................................................................................. 30 Appendix 4 .............................................................................................................. 31 Appendix 5 .............................................................................................................. 31