do siamese fighting fish actually fightWe built a whole protocol for transgenic and CRISPR knockout era for the combating fish, a species of specific mating and brooding behaviors supplementary note 3, Supplementary Material online. We thank Betta hobbyists from both Betta Club Singapore and Wild Betta Club Singapore for offering samples and footage. We acknowledge the fish facility, biocomputing facility and IT department of Temasek Lifesciences Laboratory for assist in fish tradition, high performance computing and data processing. We are grateful to Dr José Bessa and Dr Ying Yang for offering ZED and luciferase vectors, respectively. Our grateful thanks also are extended to Dr. Jinlu Wu for providing the Singapore grouper embryonic cell lines.