Publication Abstract

Life-history traits of invasive bighead goby Neogobius kessleri from the middle Danube with a prediction of who will win the goby competition

Life-history traits of invasive bighead goby Neogobius kessleri from the middle Danube with a prediction of who will win the goby competition

V. Kovac, G.H. Copp* and R.P. Sousa

Life history traits in invasive population of bighead goby from the middle Danube, including absolute and relative fecundity, egg size, number of spawning batches and size at first maturation, were examined and evaluated within an epigenetic context. Ripe bighead goby females attained 42.8–142.5 mm L_S, with absolute fecundities ranging from 669 to 5 646 eggs (mean 2 109 eggs), and relative fecundities of 61.6 to 174.0 eggs g^-1 body weight (mean 119.6 eggs). Egg diameters varied between 0.04 mm and 1.70 mm (mean = 0.57 mm). In the pre-spawning period, there was no clear size distinction in eggs (0.12 – 1.45 mm; mean = 0.52 mm) in 34.1 % of females, in 65.9 % of females two egg size groups were distinguished: Group I diameters ranged 0.06 – 0.85 mm (mean = 0.43 mm), Group II diameters ranged 0.55 – 1.70 mm (mean = 1.17 mm). Females with size-group II eggs at the beginning of the reproductive season were assumed to be ready to spawn and the others to be subsequent spawners. Bighead goby appears to be altricial compared to round goby, though in both species a shift from highly precocial towards a less precocial life history was observed. These differences, affected by epigenetic mechanisms and resulting in alternative ontogenies, may have important implications for a species’ potential success in novel environments, favouring round goby over short time scales (several years) and bighead goby over longer time scales (decades and longer).

Reference:
V. Kovac, G.H. Copp* and R.P. Sousa (2009) Life-history traits of invasive bighead goby Neogobius kessleri from the middle Danube with a prediction of who will win the goby competition. Journal of Applied Ichthyology, 25; 33-37

Kovac, V., G.H. Copp* and R.P. Sousa

Journal of Applied Ichthyology, 25; 33-37