Treasurer, J.W. and Holliday, F.G.T. (1981) Some aspects of the reproductive biology of perch Perca fluviatilis. A histological description of the reproductive cycle. J. Fish Biol., pp. 359-376
| Species | Development state | Trait | Primary Data | Secondary Data |
| Perca fluviatilis | Female | Onset of oogenesis | GSI rise steadily in August | ['August'] |
| Perca fluviatilis | Female | Intensifying oogenesis activity | Steadily increase from August until April | ['January', 'February', 'March', 'April', 'August', 'September', 'October', 'November'] |
| Perca fluviatilis | Female | Maximum GSI value | 21.3-24.3% [Immediatly prior to spawning] | 22.8 percent |
| Perca fluviatilis | Female | Oogenesis duration | From August until April | 9.0 months |
| Perca fluviatilis | Female | Resting period | 4-4.5 [From April until August] | 4.25 months |
| Perca fluviatilis | Male | Onset of spermatogenesis | August | ['August'] |
| Perca fluviatilis | Male | Main spermatogenesis activity | September-October, then decrease slightly until spawning and remain at about 5% during winter | ['January', 'February', 'March', 'September', 'October'] |
| Perca fluviatilis | Male | Maximum GSI value | 6.6-7.1 [September-October] | 6.85 percent |
| Perca fluviatilis | Male | Resting period | 0.2 [June, July] | 3.0 months |
| Perca fluviatilis | Spawning conditions | Spawning release | All eggs are shed in a single batch | Multiple |