Abdoli, A. and Pont, D. and Sagnes, P. (2005) Influence of female age, body size and environmental conditions on annual egg production of the bullhead. Journal of fish biology, pp. 1327-1341
| Species | Development state | Trait | Primary Data | Secondary Data |
| Cottus gobio | Egg | Oocyte diameter | Means between age range from 1.7-2.2, total range from 1.31 to 2.39 [egg-diameter of ripening female] | 1.95 mm |
| Cottus gobio | Female | Age at sexual maturity | Among actively reproducing female, the smallest gravid female was 2 years and oldest 7 | 2.0 year |
| Cottus gobio | Female | Length at sexual maturity | Among actively reproducing female, the smallest gravid female was 5.7 cm and 13.4 cm | 5.7 cm |
| Cottus gobio | Female | Weight at sexual maturity | Among actively reproducing female, the smallest gravid female was 2.3 g, whereas the maximum weight was 31.7 g | 2.3 kg |
| Cottus gobio | Female | Relative fecundity | Mean absolute fecundity range from 184 ±7 [At age 2 and size 72 +/1, about 3 g; and 609 ± 47 [At age 6 and size 121 ±2 and about 30 g] | 184.0 thousand eggs/kg |
| Cottus gobio | Female | Absolute fecundity | 69 to 896 eggs per female | 69.0 thousand eggs |
| Cottus gobio | Female | Oocyte development | Just before spawning, the egg size distribution per site of all sampled gravid females showed a single mode | Synchronous |
| Cottus gobio | Spawning conditions | Spawning migration distance | As bullhead are well known to be territorial fish with reduced migratory activity | No data |
| Cottus gobio | Spawning conditions | Spawning season | Females spawned in April or early in all sites | ['April'] |
| Cottus gobio | Spawning conditions | Spawning period duration | Occur over a period of about 1 month | 1.0 weeks |
| Cottus gobio | Spawning conditions | Spawning temperature | 7-8 [5-12] | 7.5 °C |
| Cottus gobio | Spawning conditions | Spawning water type | Tributaries, reaches with relatively steep river slope | No category |
| Cottus gobio | Spawning conditions | Spawning depth | The water depths were <40 cm at the end of the low flow period | 40.0 m |
| Cottus gobio | Spawning conditions | Spawning substrate | All dominated by coarse substrata, mainly cobbles and large stones | Lithophils |
| Cottus gobio | Spawning conditions | Spawning release | Females laid all their eggs during the same period [Producing only one single batch of eggs per year] Yet, Fox also found that bullhead in less productive streams lay only one batch of eggs annually but in highly productive streams may lay up to four batches of eggs | Multiple |
| Cottus gobio | Spawning conditions | Parity | Actively reproducting female range from 2 to 7 years | No category |