Abstract:
The Ponto-Caspian amphipod Dikerogammarus villosus is one of the most successful invaders in Central European rivers. Contrary to studies on its ecology, ecophysiological studies comparing the species\' physiological traits are scarce. In this context, in particular the metabolic activity of the invasive species has rarely been considered and, moreover, the few existing studies on this species report strongly deviating results. The purpose of this study was to assess the metabolic activity and behavior of D. villosus and other common European amphipod species (Gammarus fossarum, Gammarus roeselii) in relation to temperatures covering the thermal regime of the invaded habitats. Based on direct calorimetric measurements of metabolic heat dissipation at three temperature levels (5°C, 15°C and 25°C), we found the routine metabolic rate of D. villosus to be significantly lower than that of the other studied gammarid species at the medium temperature level. The estimated resting metabolic rate indicated a similar trend. At 5°C and 25°C, both routine and resting metabolic rate did not differ between species. Compared to G. fossarum and G. roeselii, D. villosus exhibited lower locomotor activity at the low and medium temperatures (5°C and 15°C). In contrast, its locomotor activity increased at the high experimental temperature (25°C). G. fossarum and G. roeselii were apparently more active than D. villosus at all studied temperatures. We conclude that D. villosus has both physiological and behavioral adaptations that lead to a reduction in metabolic energy expenditure, which is assumed to be beneficial and might contribute to its invasive success.
摘要:
里海两栖动物Dikerogammarusvillosus是中欧河流中最成功的入侵者之一。与其生态学研究相反,比较物种生理特征的生态生理研究很少。在这种情况下,特别是入侵物种的代谢活动很少被考虑,此外,对该物种的少数现有研究报告了强烈偏离的结果。这项研究的目的是评估D.villosus和其他常见的欧洲两栖动物物种(Gammarusfossarum,Gammarusroeselii)与覆盖入侵栖息地热态的温度有关。基于在三个温度水平(5°C,15°C和25°C),我们发现在中等温度水平下,D.villosus的常规代谢率显着低于其他研究的gammarid物种。估计的静息代谢率表明了类似的趋势。在5°C和25°C时,常规代谢率和静息代谢率在物种之间没有差异.与G.fossarum和G.roeselii相比,D.villosus在低温和中等温度(5°C和15°C)下表现出较低的运动活性。相比之下,在高实验温度(25°C)下,其运动活动增加。在所有研究温度下,G.fosarum和G.roeselii显然比D.villosus更活跃。我们得出的结论是,D.villosus具有生理和行为适应,导致代谢能量消耗减少,这被认为是有益的,可能有助于其侵入性的成功。