Dynamics and population structure of native Echinogammarus stammeri (Karaman, 1931) (Crustacea: Amphipoda) and non-native Gammarus roeselii Gervais, 1835 (Crustacea: Amphipoda) occurring in sympatry in Northern Italy

Gammarids are one of the most successful invaders in freshwater ecosystems due to both their diet plasticity and high reproductive capability. The Balkanic amphipod, Gammarus roeselii Gervais, 1835, has colonised a small canal in the southern part of the sub-lacustrine Ticino River basin (Northern Italy), where it lives in sympatry and shares the same habitat with the native species Echinogammarus stammeri (Karaman, 1931). We surveyed the...