Albert, A. and Vetemaa, M. and Saat, T. (2006) Laboratory-base reproduction sucess of ruffe, Gymnocephalus cernuus (L.), in brackish water is determined by maternal properties. Ecology of Freshwater Fish, pp. 105-110
| Species | Development state | Trait | Primary Data | Secondary Data |
| Gymnocephalus cernua | Egg | Egg size after water-hardening | The egg diameter was measured in the middle of the spawning season: 0.65-0.85 [In lake Peipsi], 0.9-1.1 [In Matsalu Bay], 0.95-1.25 |In Pärnu Bay] | 0.75 mm |
| Gymnocephalus cernua | Egg | Temperature for incubation | The dishes were kept under the same conditions under natural photoperiod at 16°C | 16.0 °C |
| Gymnocephalus cernua | Larvae | Initial larval size | Standard length of larvae of freswater : meanSL range from 2.05 and 2.23 and brackishwater range from 2.32-3.03 | 2.67 mm |
| Gymnocephalus cernua | Spawning conditions | Spawning release | In asynchronous spawners like ruffe, egg size in consecutive batches is found to be smaller, which is associated with the diminishing resources of the female | Multiple |