Brown et al, 1998


Brown, W.P. and Selgeby, J.H. and Collins, H.L. (1998) Reproduction and early life history of ruffe (Gymnocephalus cernuus) in the St. Louis River, a Lake Superior tributary. Journal of Great Lakes Research [J. Great Lakes Res.], pp. 217-227

Associated characteristics

Species Development state Trait Primary Data Secondary Data
Gymnocephalus cernua Egg Incubation time 5-6 [At 16°C] 5.5 days
Gymnocephalus cernua Egg Temperature for incubation 16°C 16.0 °C
Gymnocephalus cernua Egg Degree-days for incubation About 90 [5-6 days at 16°C] 5.5 °C * day
Gymnocephalus cernua Larvae Larvae behaviour Larval ruffe hatch and become pelagic within 1 to 2 weeks after egg deposition and could possibly be netrained in ballast water duting the pelagic period Pelagic
Gymnocephalus cernua Larvae Temperature during larval development Larvae were captured at Allouez Bay from 30 May to 10 July, with peak catch the week of 13 June, corresponds to a temperature of 12-17°C on the graph. Larvae were captured at whaleback from 23 May to 3 June with a peak catch the week of 30 May, which corresponds to 12-16°c on the graph 14.5 °C
Gymnocephalus cernua Larvae Onset of exogeneous feeding 120-130: Active feeding and swim-up occurring 13 days after fertilization (hatching 5-6 days after fertilization) at 16°C 125.0 °C * day
Gymnocephalus cernua Female Maximum GSI value 9-11 [May] 10.0 percent
Gymnocephalus cernua Spawning conditions Spawning season May-July ['May', 'July']
Gymnocephalus cernua Spawning conditions Spawning period duration 8 8.0 weeks
Gymnocephalus cernua Spawning conditions Spawning temperature 5-18 [mainly between 12-14] 11.5 °C
Gymnocephalus cernua Spawning conditions Parity The prolonged spawning period is possibly due to different rates of development of the ovaries among females of different ages No category