We examined small-scale distribution and feeding ecology of a non-native fish species, round goby (Neogobius melanostomus (Pallas, 1814)), in different habitats of a coastal lagoon situated in the south-western Baltic Sea. First observations of round goby in this lagoon were reported in 2011, 3 years before the current study was conducted, and information on this species’ basic ecology in different habitats is limited. We found that mainly juvenile round gobies are non-randomly distributed between habitats and that abundances potentially correlate positively with vegetation density and thus structural complexity of the environment. Abundances were highest in shallower, more densely vegetated habitats indicating that these areas might act as a refuge for small round gobies by possibly offering decreased predation risk and better feeding resources. Round goby diet composition was distinct for several length classes suggesting an ontogenetic diet shift concerning crustacean prey taxa between small (≤ 50 mm total length, feeding mainly on zooplankton) and medium individuals (51–100 mm, feeding mainly on benthic crustaceans) and another diet shift of increasing molluscivory with increasing body size across all length classes. Differences in round goby diet between habitats within the smallest length class might potentially be related to prey availability in the environment, which would point to an opportunistic feeding strategy. Here, we offer new insights into the basic ecology of round goby in littoral habitats, providing a better understanding of the ecological role of this invasive species in its non-native range, which might help to assess potential consequences for native fauna and ecosystems.

我们研究了非本地鱼类圆虾虎鱼（Neogobius melanostomus的小规模分布和摄食生态（Pallas，1814）），位于波罗的海西南部沿海泻湖的不同栖息地。2011年，即本研究进行之前的3年，首次报告了该泻湖中的go鱼的观察结果，而且该物种在不同生境中的基本生态学信息有限。我们发现，主要是轮生的虾虎鱼在栖息地之间是非随机分布的，并且其丰度与植被密度以及环境的结构复杂度呈正相关。在较浅，较茂密的生境中，丰度最高，表明这些地区可能通过降低捕食风险和提供更好的觅食资源而成为小型轮虾的避难所。虾虎鱼的日粮组成在几个不同的长度类别上是不同的，这表明甲壳类猎物类群的个体发育饮食在小型个体（≤50 mm，主要以浮游动物为食）和中型个体（51–100 mm，主要以底栖甲壳类为食）和另一个在所有长度类别中，食肉动物的饮食变化随着体重的增加而增加。最小长度类别的栖息地之间的虾虎鱼饮食差异可能与环境中的猎物可利用性有关，这将表明机会性的喂养策略。在这里，我们提供了有关沿岸生境中虾虎鱼基本生态学的新见解，可以更好地了解该入侵物种在其非本地范围内的生态作用，