Fischer Jessica, Laforsch Christian
1Animal Ecology I, University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany.
2Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany.
NPJ Microgravity. 2018 Jan 18;4:3. doi: 10.1038/s41526-017-0037-5. eCollection 2018.
For future manned long-d uration space missions, the supply of essentials, such as food, water, and oxygen with the least possible material resupply from Earth is vital. This need could be satisfied utilizing aquatic bioregenerative life support systems (BLSS), as they facilitate recycling and autochthonous production. However, few organisms can cope with the instable environmental conditions and organic pollution potentially prevailing in such BLSS. Ostracoda, however, occur in eu- and even hypertrophic waters, tolerate organic and chemical waste, varying temperatures, salinity, and pH ranges. Thus, according to their natural role, they can link oxygen liberating, autotrophic algae, and higher trophic levels (e.g., fish) probably also in such harsh BLSS. Yet, little is known about how microgravity (µ) affects Ostracoda. In this regard, we investigated locomotion and orientation, as they are involved in locating mating partners and suitable microhabitats, foraging, and escaping predators. Our study shows that Ostracoda exhibit altered activity patterns and locomotion behavior (looping) in µ. The alterations are differentially marked between the studied species (i.e., 2% looping in , ~50% in ) and also the thresholds of gravity perception are distinct, although the reasons for these differences remain speculative. Furthermore, neither species acclimates to µ nor orientates by light in µ. However, Ostracoda are still promising candidates for BLSS due to the low looping rate of and our findings that the so far analyzed vital functions and life-history parameters of remained similar as under normal gravity conditions despite of its high looping rate.
对于未来的载人长期太空任务而言，以最少的来自地球的物资补给来供应食物、水和氧气等必需品至关重要。利用水生生物再生生命支持系统（BLSS）可以满足这一需求，因为它们有助于循环利用和本地生产。然而，很少有生物能够应对此类BLSS中可能普遍存在的不稳定环境条件和有机污染。然而，介形虫出现在富营养甚至超富营养水域中，能耐受有机和化学废物、不同的温度、盐度和pH范围。因此，根据它们的自然作用，它们可能也能在如此恶劣的BLSS中连接释放氧气的自养藻类和更高营养级（如鱼类）。然而，关于微重力（µ）如何影响介形虫，人们知之甚少。在这方面，我们研究了运动和定向，因为它们涉及寻找交配伙伴和合适的微生境、觅食以及躲避捕食者。我们的研究表明，介形虫在微重力环境下表现出改变的活动模式和运动行为（打转）。在所研究的物种之间，这些改变的程度有所不同（即，[物种1]中有2%打转，[物种2]中约50%打转），而且重力感知阈值也不同，尽管这些差异的原因仍属推测。此外，这两个物种都不会适应微重力环境，也不会在微重力环境下根据光线定向。然而，由于[物种1]的低打转率，以及我们的研究结果表明，尽管[物种2]打转率高，但到目前为止所分析的其重要功能和生活史参数在正常重力条件下仍保持相似，所以介形虫仍是BLSS的有前景的候选生物。
