Kovac, 1998



Citation


Kovac, V. (1998) Biology of Eurasian Ruffe from Slovakia and Adjacent central european countries. J. Great Lakes Res., pp. 205-216

Associated characteristics


Species Development state Trait Primary Data Secondary Data
Gymnocephalus cernuus Spawning conditions Spawning temperature 7.1-20.2 13.65 °C
Gymnocephalus cernuus Spawning conditions Spawning water type Spawning of Eurasian ruffe in the the Baka side-arm system of the River Danube, in the Orava Reservoir, Lipno reservoir No category
Gymnocephalus cernuus Egg Egg adhesiveness Very adhesive Adhesive
Gymnocephalus cernuus Female Relative fecundity 585-1540 1062.5 thousand eggs/kg
Gymnocephalus cernuus Female Age at sexual maturity 2 [Part of the population at 1] 2.0 years
Gymnocephalus cernuus Egg Degree-days for incubation 136 136.0 °C * day
Gymnocephalus cernuus Spawning conditions Spawning migration distance Ruffe do not make long migrations, however short diurnal and seasonal movements are common No data
Gymnocephalus cernuus Female Onset of oogenesis Between September and March, gonad weight increases slowly ['March', 'September']
Gymnocephalus cernuus Egg Egg size after water-hardening 0.97-1.07 [Activated egg] 1.02 mm
Gymnocephalus cernuus Female Oocyte development Polycyclic, with asynchrous ripening of eggs and protracted spawning Asynchronous
Gymnocephalus cernuus Spawning conditions Spawning season Mid-April to Mid-June ['April', 'June']
Gymnocephalus cernuus Larvae Temperature during larval development At water temperature ranging from 16.2 to 23.2°C (mean 19.4°C), the larval period lasted 20 days 16.2 °C
Gymnocephalus cernuus Female Length at sexual maturity 5.7-9 SL [All female exceeding 9 cm were mature] 7.35 cm
Gymnocephalus cernuus Male Length at sexual maturity 3.2-8 SL [All male exceeding 8 cm were mature] 5.6 cm
Gymnocephalus cernuus Larvae Initial larval size 3.35-3.81 3.58 mm
Gymnocephalus cernuus Larvae Larvae behaviour Most to the time they stay at the bottom Demersal
Gymnocephalus cernuus Female Age at sexual maturity 2 [Part of the population at 1] 2.0 year
Gymnocephalus cernuus Spawning conditions Parity Most individuals atain a maximum age of 6 years, excepeionally 7 or 8 years No category