Sulistyo, I. and Fontaine, P. and Rinchard, J. and Gardeur, J.N. and Migaud, H. and Capdeville, B. and Kestemont, P. (2000) Reproductive cycle and plasma levels of steriods in male Eurasian perch Perca fluviatilis. Aquat. Living. Resour., pp. 99-106
| Species | Development state | Trait | Primary Data | Secondary Data |
| Perca fluviatilis | Male | Onset of spermatogenesis | End of August | ['August'] |
| Perca fluviatilis | Male | Onset of spermatogenesis | August | ['August'] |
| Perca fluviatilis | Male | Main spermatogenesis activity | September | ['September'] |
| Perca fluviatilis | Male | Maximum GSI value | 8.5 ± 1.8 [September] | 8.5 percent |
| Perca fluviatilis | Male | Spermatogenesis duration | 1.5 [The development of the testes occurred within about 6 weeks in end of August and September] | 1.5 months |
| Perca fluviatilis | Male | Resting period | 0.2 ± 0.1 [Late June, July, August) | 4.0 months |