“…The interaction between environmental factors, the neuroendocrine system, and reproduction in fish has not yet been fully explored, however, a considerable number of related studies have been published. Similar to other vertebrates, reproduction in fish depends on the neuroendocrine system, which initiates and controls gametogenesis (formation of female oocyte and male spermatozoon) and steroidogenesis (formation of steroids), through the activation of hypothalamus-pituitary-gonad axis (HPG) or the gonadotropic axis (Levavi-Sivan and Yaron, 1993;Kah et al, 1993;Van der Kraak et al, 1998;Fink, 2000;Tena-Sempere and Huhtaniemi, 2003;Kajimura et al, 2004;Marchesan et al, 2005;Pinilla et al, 2012). The initiation and completion of reproductive activity in teleost fish is controlled by photoperiod, which ensures an appropriate reproduction season favorable for offspring survival (Bromage et al, 2001).…”