Department of Mechanical and Materials Engineering, Florida International University, 10555 W Flagler St, Miami, FL, 33174, USA.
Department of Fisheries, Animal and Veterinary Science, University of Rhode Island, Kingston, RI, 02881, USA.
Sci Rep. 2023 Apr 19;13(1):6370. doi: 10.1038/s41598-023-32873-1.
Current studies on abiotic impacts on Artemia, a crustacean which is widely used in aquaculture, and ecotoxicology, often focus on endpoint analysis (e.g., hatching rates, survival). Here, we demonstrate that a mechanistic understanding can be obtained through measurement of oxygen consumption in real-time over an extended time period in a microfluidic platform. The platform enables high level control of the microenvironment and direct observation of morphological changes. As a demonstration, temperature and salinity are chosen to represent critical abiotic parameters that are also threatened by climate change. The hatching process of Artemia consists of four different stages: hydration, differentiation, emergence, and hatching. Different temperatures (20, 35, and 30 °C) and salinities (0, 25, 50, and 75 ppt) are shown to significantly alter the duration of hatching stages, metabolic rates, and hatchability. Specifically, the metabolic resumption of dormant Artemia cysts was significantly enhanced at higher temperatures and moderate salinity, however, the time needed for this resumption was only dependent on higher temperatures. Hatchability was inversely related to the duration of the differentiation stage of hatching, which persisted longer at lower temperatures and salinities. The current approach of investigation of metabolism and corresponding physical changes can be employed to study hatching processes of other aquatic species, even those with low metabolic rate.
目前的研究主要集中在非生物因素对卤虫（一种广泛应用于水产养殖的甲壳类动物）的影响以及生态毒理学方面，通常侧重于终点分析（例如孵化率、存活率）。在这里，我们通过在微流控平台上实时测量长时间的耗氧量来证明，可以获得对机制的理解。该平台可以高度控制微环境，并直接观察形态变化。作为一个演示，我们选择温度和盐度来代表关键的非生物参数，这些参数也受到气候变化的威胁。卤虫的孵化过程由四个不同的阶段组成：水化、分化、出现和孵化。不同的温度（20、35 和 30°C）和盐度（0、25、50 和 75 ppt）显著改变了孵化阶段的持续时间、代谢率和孵化率。具体来说，休眠卤虫卵囊的代谢恢复在较高温度和中等盐度下显著增强，但是，这种恢复所需的时间仅取决于较高的温度。孵化率与孵化分化阶段的持续时间呈反比，在较低温度和盐度下，这个阶段持续时间更长。目前，这种研究代谢和相应物理变化的方法可以用于研究其他水生物种的孵化过程，甚至是那些代谢率较低的物种。
