Rodriguez, L. and Carrillo, M. and Sorbera, L.A. and Zohar, Y. and Zanuy, S. (2004) effects of photoperiod on pitiuary levels of three forms of GnRH and reproductive hormones in the male European sea bass (Dicentrarchus labrax, L.) during testicular differentiation and first testicular recrudescence. General and Comparative Endocrinology, pp. 37-48
| Species | Development state | Trait | Primary Data | Secondary Data |
| Dicentrarchus labrax | Male | Onset of spermatogenesis | October | ['October'] |
| Dicentrarchus labrax | Male | Main spermatogenesis activity | December | ['December'] |
| Dicentrarchus labrax | Male | Maximum GSI value | 2.5 [In January] | 2.5 percent |