PHENOTYPIC PLASTICITY OF THE AMUR SLEEPER (<i>PERCCOTTUS GLENII</i>) INVASIVE POPULATIONS DURING THE COLONISATION OF WATER BODIES

Abstract

The variability of the body shape in invasive fish species - Amur sleeper (Perccottus glenii) - from natural and anthropogenic water bodies of the Middle Urals with different completeness of the species composition was studied by the use of geometric morphometrics methods. We compared samples of the Amur sleeper from neighboring adjacent water bodies - Lake Shitovskoye and two peat quarries filled with water. Samples of different seasons and years of collection were taken in the lake, which allowed us to correlate the influence of climate and season on the morphogenesis of the Amur sleeper. According to the control catches, the fish community of the lake is represented by 10 species, i.e. it has a poly-species composition: 6 native species (roach, river perch, ruff, tench, crucian carp, and pike) and 4 alien species (bream, belica, Amur sleeper, carp). The share of the Amur sleeper in the control catches in the lake was no more than 3-5%. In the water bodies of peat quarries, oligoid communities of 2 species were formed (Amur sleeper and crucian carp). Discriminant analysis of the body shape of fish from the lake and peat pits allowed us to reveal the origin of 93-98% of individuals. Comparing the samples of the younger (2+-3+ years) and older (4+-7+ years) age groups of fish divided by sex and biotope, different directions of changes in the shape of the Amur sleeper body in ontogenesis were revealed between the biotopic groups. The range of age variability was almost 5 times lesser than the intergroup biotopic differences of fish from ecologically contrasting water bodies. Seasonal and inter-annual intra-population variability of body shape in the Amur sleeper in the lake is significantly lesser pronounced than the intergroup differences between samples from the lake and peat quarries. Sex differences accounted for only 6% of the intergroup variance (3 times lower than the level of age differences), and in the poly-species lake community, sex differences decrease with age, and in the water bodies of quarries, on the contrary, they increase. Within-group morphological disparity ( MNND ) is significantly higher in samples from peat quarries. The data obtained are of a key character, since they characterize a high degree of phenotypic plasticity of the Amur sleeper and a rapid adaptive restructuring of its morphogenesis to different conditions of natural and anthropogenic water bodies of the Middle Urals.