Darchambeau, F. and Poncin, P. (1997) Field observations on the spawning behaviour of European grayling. Journal of fish biology, pp. 1066-1068
| Species | Development state | Trait | Primary Data | Secondary Data |
| Thymallus thymallus | Female | Length at sexual maturity | Two females (total lengths 25 and 30 cm) | 30.0 cm |
| Thymallus thymallus | Female | Female sexual dimorphism | Distinguished from the males by their pale colour pattern | Present |
| Thymallus thymallus | Male | Length at sexual maturity | On each spawning area, only one male (31 cm total length for the upstream site; 34 cm for the downstream site) was territorial for 2 days. Two other males (both about 30 cm total length) did not appear to defend territories. | 31.0 cm |
| Thymallus thymallus | Spawning conditions | Spawning period duration | Spawning period ran from 6 to 8 April | 6.0 weeks |
| Thymallus thymallus | Spawning conditions | Spawning temperature | Average temperature of 8.8°C | 8.8 °C |
| Thymallus thymallus | Spawning conditions | Spawning depth | Most spawing occurred in 20-55 cm water depth | 37.5 m |
| Thymallus thymallus | Spawning conditions | Spawning substrate | The stream beds consisted of fine gravel (1-2 cm)mixed up with larger pebbles (5-10 cm) and stones (15-25 cm). | Lithophils |
| Thymallus thymallus | Spawning conditions | Mating system | A spawning act was considered successful when the behavioural sequence observed in a pair included 'apporach', 'quiverin', 'dorsal fin clasping', 'tail crossing', 'head and tail-up posture', and finally 'gaping', associated with the release of eggs en sperm [Of the 25 spawning acts observed, 24 included the female and the territorial male with one spawning act included two males and one female; of the 70 behavioural sequences, 18 involved a second male that joined he pair before spawning] | No category |