Malison, J.A and Porcarione, L.S. and Barry, T.P. and Kapuscinski, A.R. and Kayes, T.P. (1994) Endocrine and gonadal changes during the annual reproductive cycle of the freshwater teleost, Stizostedion vitreum. Fish. Phys. Biochem., pp. 473-484
| Species | Development state | Trait | Primary Data | Secondary Data |
| Sander vitreus | Female | Oocyte development | Group-synchronous ovarian developpement | Group-synchronous |
| Sander vitreus | Female | Onset of oogenesis | October [7.6% in November] | ['October', 'November'] |
| Sander vitreus | Female | Intensifying oogenesis activity | January-February | ['January', 'February'] |
| Sander vitreus | Female | Maximum GSI value | About 16-17 [April] | 16.5 percent |
| Sander vitreus | Female | Oogenesis duration | From October to April | 7.0 months |
| Sander vitreus | Female | Resting period | From May to October | 7.0 months |
| Sander vitreus | Male | Onset of spermatogenesis | September, GSI rise significantly and stay relatively constant until March | ['March', 'September'] |
| Sander vitreus | Male | Main spermatogenesis activity | March [Also very important in September] | ['March', 'September'] |
| Sander vitreus | Male | Maximum GSI value | Mean 3.2%, up to 3.7% [Prior to spawning, April] | 3.2 percent |
| Sander vitreus | Male | Spermatogenesis duration | From October until December | 4.0 months |
| Sander vitreus | Male | Resting period | <1% [From May through September] | 1.0 months |
| Sander vitreus | Spawning conditions | Spawning season | Walleye are one of the first species to spawn in the spring, shortly after ice break-up. Early to mid-April | ['April', 'May', 'June'] |