Data for: Life in a changing environment: Dreissenids’ feeding response to different temperature

Invasive species have far-reaching consequences for whole ecosystems. In particular, filter feeders such as zebra and quagga mussels have a huge impact on lake ecosystems by filtering out resources that are otherwise used by native filter feeders. Quagga mussels can colonise deeper parts of a lake while zebra mussels prefer shallow areas. Both species show large variability in shell morphology, but only quagga mussels show a shallow and deep morphotype. The aim of this study is to investigate the depth adaptation of both dreissenid species. We hypothesize potential advantages of the quagga mussel over the zebra mussel with regard to feeding. We conducted common garden experiments, where we measured filtration rates at different temperatures (4, 12, and 20 °C) of quagga mussels collected from different water depths (1, 30, and 60 m) and compared them to zebra mussel from 1m depth. We found filtration rates to be strongly temperature dependent, and in particular, lower at 4 °C. Overall, zebra mussels fed less than quagga mussels taken from the same water depth. Quagga mussels collected from 1 m depth fed more at higher temperature than quaggas from 30 and 60 m depth. We hypothesize that deep-water mussels are less sensitive to lower temperature and have a higher temperature threshold to increase their filtration. Otherwise, filtration rates were independent of the depth of origin of the mussels. Our results indicate that zebra mussels are less competitive filter feeders compared to quagga mussels and quagga mussels are not locally adapted with regard to their feeding. Rather, quagga mussels are better accustomed to a wider range of temperatures in shallow water.

外来入侵物种会对整个生态系统造成深远影响。具体而言，滤食性生物如斑马贻贝（zebra mussel）与纹斑贻贝（quagga mussel）可通过滤食原本可供本地滤食生物利用的资源，对湖泊生态系统造成巨大冲击。纹斑贻贝可定植于湖泊较深区域，而斑马贻贝则偏好浅水环境。两类物种的贝壳形态均存在显著变异，但仅纹斑贻贝表现出浅栖与深栖两种形态型。本研究旨在探究两种饰贝属物种的水深适应性。我们提出假说：纹斑贻贝在摄食能力上相较斑马贻贝具有潜在优势。本研究开展了同质园实验（common garden experiments），分别测定了采自不同水深（1 m、30 m与60 m）的纹斑贻贝，以及采自1 m水深的斑马贻贝在不同温度（4 ℃、12 ℃与20 ℃）下的滤食率，并进行对比分析。研究发现滤食率强烈依赖于环境温度，尤其在4 ℃时滤食率显著降低。总体而言，相同水深来源的斑马贻贝的摄食量低于纹斑贻贝。采自1 m水深的纹斑贻贝在较高温度下的摄食量高于采自30 m与60 m水深的纹斑贻贝。我们进一步提出假说：深水来源的贻贝对低温的敏感性更低，且提升滤食率所需的温度阈值更高。除此之外，滤食率与贻贝的原生水深无关。本研究结果表明，相较于纹斑贻贝，斑马贻贝作为滤食生物的竞争力较弱；且纹斑贻贝并未在摄食方面表现出本地适应性，反而更适应浅水环境中更广范围的温度波动。