Rapid adaptation of Brachionus angularis (Rotifera) to invasion by Brachionus calyciflorus

Hydrobiologia ◽  
2019 ◽  
Vol 844 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Yi-Long Xi ◽  
Ke-Qiang Huang ◽  
Ling Pan ◽  
Han Zhu ◽  
Ya-Li Ge ◽  
...  
Biologia ◽  
2013 ◽  
Vol 68 (6) ◽  
Author(s):  
Paweł Napiórkowski ◽  
Teresa Napiórkowska

AbstractThe diversity and longitudinal variation of zooplankton in the lower Vistula River were analyzed. Samples were taken from 40 stations located along a 272-km long section of the lower river course. During the study the unique technique of taking samples from “the same water” was used. The zooplankton community was dominated by rotifers and nauplii — larval stages of copepods. The most abundant species were: Brachionus angularis, Brachionus calyciflorus and Brachionus budapestiensis. The zooplankton species diversity in the main channel of the lower Vistula River was similar to other large European rivers; however, its abundance was lower. The diversity, abundance and biomass of potamoplankton steadily decreased downstream. This could be related both to scarcity of storage zones for potamoplankton development in the river due to the extensive regulation processes, and changes in hydrological conditions of the main channel (by the straightening of riverbed) where the samples were collected.


Author(s):  
Kun Zhang ◽  
Quan Wan ◽  
Yi-Long Xi

Intensive interspecific competition for limited resource often can result in the exclusion of inferior competitors, decrease the species diversity and alter the structure of the zooplankton community. Competitive experiments between Brachionus calyciflorus and Brachionus angularis were conducted at three Scenedesmus densities (0.5 × 106, 1.0 × 106 and 2.0 × 106 cells ml−1) and four initial inoculation densities (numerically, 100% B. calyciflorus, 75% B. calyciflorus and 25% B. angularis, 50% each of the two species, 25% B. calyciflorus and 75% B. angularis, and 100% B. angularis). The results showed that at the low food level, B. angularis outcompeted B. calyciflorus and vice versa at the high food levels. At the intermediate food level, B. angularis was displaced by B. calyciflorus at nearly all the initial inoculation densities except for 75% B. angularis, at which both species coexisted until the termination of the experiment. When grown alone at 0.5 × 106, 1.0 × 106 and 2.0 × 106 cells ml−1 of Scenedesmus, B. calyciflorus reached the peak abundance values of 34 ± 4, 69 ± 5 and 101 ± 9 individuals ml−1 and had population growth rates of 0.608 ± 0.032, 0.654 ± 0.033 and 0.518 ± 0.039 d−1, respectively. The corresponding values for B. angularis were 265 ± 8, 330 ± 30 and 802 ± 87 individuals ml−1 and 0.623 ± 0.020, 0.770 ± 0.036 and 0.871 ± 0.013 d−1. The results suggest that the outcome of competition depends not only on the size of the competing species and food availability but also on their colonizing density.


2010 ◽  
Vol 36 (5) ◽  
pp. 935-942 ◽  
Author(s):  
Jin-Yan ZHANG ◽  
Yi-Long XI ◽  
Qin MA ◽  
Xian-Ling XIANG

2021 ◽  
pp. 103530462098360
Author(s):  
Fiona Jenkins ◽  
Julie Smith

In the COVID-19 pandemic, people’s dwellings suddenly became a predominant site of economic activity. We argue that, predictably, policy-makers and employers took the home for granted as a background support of economic life. Acting as if home is a cost-less resource that is free for appropriation in an emergency, ignoring how home functions as a site of gendered relations of care and labour, and assuming home is a largely harmonious site, all shaped the invisibility of the imposition. Taking employee flexibility for granted and presenting work-from-home as a privilege offered by generous employers assumed rapid adaptation. As Australia emerges from lockdown, ‘building back better’ to meet future shocks entails better supporting adaptive capabilities of workers in the care economy, and of homes that have likewise played an unacknowledged role as buffer and shelter for the economy. Investing in infrastructure capable of providing a more equitable basis for future resilience is urgent to reap the benefits that work-from-home offers. This article points to the need for rethinking public investment and infrastructure priorities for economic recovery and reconstruction in the light of a gender perspective on COVID-19 ‘lockdown’ experience. JEL Codes: E01, E22, J24


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