Growth features of the Amur sleeper Perccottus glenii (Actinopterygii: Odontobutidae) in the invaded Carpathian basin, Hungary

Background. The Amur sleeper, Perccottus glenii Dybowski, 1877, is the most invasive alien fish species inthe native aquatic communities in central Europe. Although the accelerated invasion of P. glenii has been welldocumented, there is little information on the ecological and growth parameters of non-native populations in thisregion. The aim of this study was to describe the growth features of the population of P. glenii in a shallow oxbowlake in the Carpathian Basin.Materials and methods. Our study sample consisted of 1239 individuals (628 ♂ + 611 ♀) collected from anoxbow lake near the Tisza River in the same month for three years (2013–2015). The length, weight, age structure,sex-dependent growth rate, and the condition factor of the collected specimens were determined.Results. The sex ratio was 0.49 (♀ ÷ (♀ + ♂)). The standard length and weight of the collected P. glenii specimensranged from 20.7 to 127.7 mm and from 0.3 to 75.8 g, respectively. The length–weight relations (SL–W) wereallometrically negative for the males (W = 3.2 × 10–5SL2.960), females (W = 3.8 × 10–5SL2.921), and both sexes (W =3.5 × 10–5SL2.940), without significant differences between males and females. According to the length-frequencyanalysis, five age groups were differentiated. The von Bertalanffy growth models were L∞ = 138.87 mm, k = 0.21,t0 = –0.54 (♂), L∞ = 174.21 mm, k = 0.17, t0 = –0.33 (♀), L∞ = 154.01 mm, k = 0.19, t0 = –0.45 (♂ + ♀). The growthperformance parameters were Ф′ = 3.61 (♂), Ф′ = 3.71 (♀), Ф′ = 3.65 (♂ + ♀), respectively.Conclusion. Due to unequal investment in reproduction, there was a significant difference in the growth ratebetween males and females. The literature data showed that invasive gobies and odontobutids (e.g., P. glenii)exhibit more opportunistic reproduction strategy in newly colonized areas, which may contribute to the invasionsuccess. This strategy (e.g., earlier maturation, longer spawning period, etc.) results in slower growth rate due toenergetic trade-off between reproduction and somatic growth. The observed growth rate of invasive Amur sleeperpopulation (especially in the older age groups) was slower than that of native and more established naturalizedpopulations in Eurasia