Data from: Invasion strategies in round goby (Neogobius melanostomus): is bigger really better?

Few studies have systematically investigated mid- or long-term temporal changes of biological characteristics in invasive alien species considering the different phases of an invasion. We studied the invasion performance of one of the most invasive species worldwide, the round goby Neogobius melanostomus, from total absence over first occurrence until establishment from 2010 to 2015 in the upper Danube River. After an upstream movement of the invasion front of about 30 river km within four years, the pattern that round goby pioneering populations significantly differ from longer established ones has been confirmed: Pioneering populations at the invasion front comprised more females than males, and adult specimens with a larger body size compared to those at longer inhabited areas. On the population-level, the proportion of juveniles increased with time since invasion. The results of this study provide support for the previously postulated ´bigger is better´ and ´individual trait utility´ hypotheses explaining invasion success in round goby. Pioneering invaders with their greater exploratory behavior, highly adaptive phenotypic plasticity and increased competitive ability seem to act as prime emperors of new habitats, strongly following and benefiting from man-made river-bank structures.目前鲜有研究结合入侵进程的不同阶段，系统探究外来入侵物种生物学特征的中长期时序变化。本研究以全球入侵性最强的物种之一——黑口新鰕虎（Neogobius melanostomus）为研究对象，对2010至2015年多瑙河上游河段中该物种从完全无分布、首次出现直至成功建立种群的入侵进程展开探究。在四年内入侵前沿向上游推进约30河公里后，本研究证实黑口新鰕虎的先锋种群与长期定居种群存在显著差异：入侵前沿的先锋种群雌性个体数量多于雄性，且成体体型较长期栖息区域内的个体更大。在种群层面，幼体占比随入侵时长的增加而升高。本研究结果为此前提出的解释黑口新鰕虎入侵成功的‘体型优势（bigger is better）’与‘个体性状效用（individual trait utility）’假说提供了支撑。具备更强探索行为、高度适应性表型可塑性以及更强竞争能力的先锋入侵个体，俨然成为新生栖息地的核心拓殖者，它们紧密依附并受益于人工河岸构筑物。