Abstract：
Turbidity can be a result of suspended natural particles, such as sediment, or anthropogenic particles such as microplastics. This study assessed whether Daphnia magna, a pelagic filter feeder known to ingest suspended particles, have an altered response to equally turbid environments caused by the presence of either suspended bentonite or suspended polyethylene microplastics. Compared to controls, daphnids exposed to suspended bentonite maintained their feeding efficiency and increased their digestive activity, as measured by mandibular movement, peristalsis, and expulsion, to pass bentonite through the digestive tract. The same effects were not seen in microplastic-exposed individuals, in which feeding efficiency was decreased and only peristaltic movement was increased but without a coordinated increase in expulsion, suggesting that microplastics do not have the same ability as bentonite to pass through the digestive tract. This study highlights the need to discern the identities of particulates contributing to turbid environments as different particles, even of the same size, can have different effects on filter feeders, which inherently ingest suspended particles.
摘要：
浊度可能是悬浮的天然颗粒的结果，如沉积物，或微塑料等人为颗粒。这项研究评估了大型蚤是否，一种已知摄取悬浮颗粒的中上层过滤器喂食器，由于悬浮膨润土或悬浮聚乙烯微塑料的存在，对同样浑浊的环境的反应发生了变化。与对照组相比，daphnids暴露于悬浮的膨润土保持他们的摄食效率和增加他们的消化活动，通过下颌运动来衡量，蠕动,和驱逐，使膨润土通过消化道。在暴露于微塑料的个体中没有看到相同的效果，其中进食效率降低，仅蠕动运动增加，但排出量没有协调增加，这表明微塑料不具有与膨润土相同的通过消化道的能力。这项研究强调了将导致浑浊环境的颗粒物识别为不同颗粒的必要性，即使大小相同，可以对过滤器进料器产生不同的影响，固有地摄取悬浮颗粒。
