Tomlinson, M.L. and Perrow, M.R. (2003) Ecology of the bullhead., pp.
| Species | Development state | Trait | Primary Data | Secondary Data |
| Cottus gobio | Egg | Egg size after water-hardening | 2-2.5 | 2.25 mm |
| Cottus gobio | Egg | Egg adhesiveness | Adhere to the underside of the stone | Adhesive |
| Cottus gobio | Egg | Incubation time | 20-30 days | 25.0 days |
| Cottus gobio | Larvae | Initial larval size | 6-7 | 6.5 mm |
| Cottus gobio | Larvae | Larvae behaviour | The young absorb their yolk sac after which, as fry (9 mm in length) they are ready to disperse | Demersal |
| Cottus gobio | Larvae | Full yolk-sac resorption | Large yolk-sac absorbed in 10 days | 10.0 °C * day |
| Cottus gobio | Male | Male sexual dimorphism | Males are deadily distinguished at spawning time by their dark colouration, a cremy dorsal edge to the first dorsal fin, and protruding genial papillae | Absent |
| Cottus gobio | Spawning conditions | Homing | Fish are faithful to permanent shelter for many years; Bullhead developed a fixation for their "home" stone, selecting it above others even when it moved, although for a short time the fish occasionally returned to its stone's original location. This suggests bullheads may home effectively; a finding that was supported by a field experiment in which 87% of fish were found under the stone six days after initial capture. | Present |
| Cottus gobio | Spawning conditions | Spawning season | Spawn from February to June | ['February', 'March', 'April', 'May', 'June'] |
| Cottus gobio | Spawning conditions | Spawning site preparation | The male excavates a nest under a suitable large stone to attract female | No category |
| Cottus gobio | Spawning conditions | Mating system | Some males may attract more than one female | No category |
| Cottus gobio | Spawning conditions | Spawning release | Typically once for females in upland streams, and up to four times in warmer, more productive lowland streams [Females adopt fractional reproduction in the latter, with successive batches of secondary oocytes developping into eggs, which the females then lays, perhaps with different partners] | Multiple |
| Cottus gobio | Spawning conditions | Spawning release | Females lays a batch of up to 400 eggs | Multiple |
| Cottus gobio | Spawning conditions | Parental care | The male defends the brood against egg predators, and manages the nest by fanning the eggs with his pectoral fins. | Male parental care |