scholarly journals Feasibility of planctomycetes as a nutritional or supplementary food source forDaphniaspp

2016 ◽  
Vol 52 ◽  
pp. 317-325 ◽  
Author(s):  
S. C. Antunes ◽  
R. A. Almeida ◽  
T. Carvalho ◽  
O. M. Lage
2020 ◽  
Vol 16 (6) ◽  
pp. 20200133 ◽  
Author(s):  
Johan F. Nilsson ◽  
Jan-Åke Nilsson ◽  
Juli Broggi ◽  
Hannah Watson

The combination of short days and long cold winter nights, in temperate regions, presents a major challenge for small diurnal birds. Small birds regularly employ heterothermy and enter rest-phase hypothermia during winter nights to conserve energy. However, we know little about how environmental conditions, such as food availability, shape these strategies. We experimentally manipulated food availability in winter to free-living great tits Parus major . A ‘predictable' and constant food supply was provided to birds in one area of a forest, while birds in another area did not have access to a reliable supplementary food source. We found that predictability of food affected the extent of nocturnal hypothermia, but the response differed between the sexes. Whereas male nocturnal body temperature was similar regardless of food availability, females exposed to a naturally ‘unpredictable' food supply entered deeper hypothermia at night, compared with females that had access to predictable food and compared with males in both treatment groups. We suggest that this response is likely a consequence of dominance, and subdominant females subject to unpredictable food resources cannot maintain sufficient energy intake, resulting in a higher demand for energy conservation at night.


2017 ◽  
Vol 111 (6) ◽  
pp. 825-840 ◽  
Author(s):  
M. C. Marinho ◽  
O. M. Lage ◽  
José Catita ◽  
S. C. Antunes

1986 ◽  
Vol 43 (6) ◽  
pp. 1277-1284 ◽  
Author(s):  
D. C. Lasenby ◽  
T. G. Northcote ◽  
M. Fürst

Fisheries biologists have greatly altered the natural distribution of the crustacean Mysis relicta by introducing it into many lakes in both North America and Scandinavia to serve as a supplementary food source for fish. The original concept of Mysis as a deepwater benthic organism which remains isolated in the profundal zone of lakes needs to be modified to include its downstream dispersal capabilities. After introduction to a lake, Mysis will probably eventually reach all lakes in the downstream watershed. Recent studies indicate that rates of increase of introduced Mysis populations probably depend on available food and temperature. As well, introduced populations have been shown to modify benthic, phytoplankton, zooplankton, and fish communities. Most Mysis introductions have taken place without consideration of general criteria suggested for introduced species.


Acarologia ◽  
2021 ◽  
Vol 61 (1) ◽  
pp. 84-93
Author(s):  
Guang-Yun Li ◽  
Nick Pattison ◽  
Zhi-Qiang Zhang

Establishment and maintenance of the natural enemy are critical for successful biological control of pests on plants without alternative food for predators. Great efforts have been devoted to exploring suitable supplementary food for predators. In this study, we evaluated the feasibility of using Tyrophagus curvipenis (Fain and Fauvel) (Acari: Acaridae) as a supplementary food source for Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) by investigating the survival and development of N. cucumeris at different prey densities with the influence of conspecifics. Furthermore, we investigated predation rates and their body size at adult emergence. The results showed that N. cucumeris developed from egg to adult in approximately six days. Survival rates of immature predators increased significantly with the given prey density. No significant difference in body size was found between the survived adults fed at different prey density, but the females were always larger than males. To conclude, T. curvipenis can be an excellent alternative food source for the biological control agent N. cucumeris.


Author(s):  
D.R. Hill ◽  
J.R. McCurry ◽  
L.P. Elliott ◽  
G. Howard

Germination of Euonymous americanus in the laboratory has previously been unsuccessful. Ability to germinate Euonymous americanus. commonly known as the american strawberry bush, is important in that it represents a valuable food source for the white-tailed deer. Utilizing the knowledge that its seeds spend a period of time in the rumin fluid of deer during their dormant stage, we were successful in initiating germination. After a three month drying period, the seeds were placed in 25 ml of buffered rumin fluid, pH 8 at 40°C for 48 hrs anaerobically. They were then allowed to dry at room temperature for 24 hrs, placed on moistened filter paper and enclosed within an environmental chamber. Approximately four weeks later germination was detected and verified by scanning electron microscopy; light microscopy provided inadequate resolution. An important point to note in this procedure is that scarification, which was thought to be vital for germination, proved to be unnecessary for successful germination to occur. It is believed that germination was propagated by the secretion of enzymes or prescence of acids produced by microorganisms found in the rumin fluid since sterilized rumin failed to bring about germination.


2018 ◽  
Vol 1 (01) ◽  
pp. 18-21
Author(s):  
Yulian Syahputri ◽  
Diana Widiastuti

Dragon fruit skin, waste material (dragon fruit waste), will have a profitable sale value if it can be used as a food raw material. Dragon fruit skin waste contains relatively high dietary fiber so it can be used as a food raw material. This study aims to utilize dragon fruit skin waste for the manufacture of dragon fruit skin flour as an alternative food source. Some tests are made on white-meat dragon fruit skin, red-meat dragon fruit skin and super red dragon fruit skin. The preliminary study is the soaking of the three types of dragon fruit skin in two solutions, namely 0.1% sodium citrate and 0.1% sodium metabisulfite to prevent the browning effect on flour. Dragon fruit skin flour from the soaking with both solutions is then characterized physically, including its texture, color, flavor and rendement. The best physical characterization is followed by chemical characterization, including the contents of water, ash, protein, fat, carbohydrate, dietary fiber, minerals (Fe, Na, K, Ca and P), and also microbiological characterization of Escherichia coli, molds and Bacillus cereus. The chemical and microbiological characterization shows that the red-meat dragon fruit skin flour has better results than the white-meat and super red dragon fruit skin flour does. The red-meat dragon fruit skin flour contains 8.80% water, 0.20% ash, 2.35% fat, 7.69%, protein, 68,29% carbohydrate and 28,72% dietary fiber as well as 4.40 mg K, 8.76 mg Na , 0.65 mg Fe , 10.20 mg Ca and 32.58 mg P. Keywords: Waste, Dragon Fruit Skin, Dragon Fruit Skin Powder, Alternative Food Source


2020 ◽  
Vol 4 (1) ◽  
pp. 1-12
Author(s):  
Elizabeth C. Lopardo ◽  
Clare M. Ryan

Four dams on the lower Snake River in Washington State generate hydropower and allow for regional agriculture and barge shipping to Portland OR. However, the dams impede the migration of local salmon populations (Oncorhynchus spp.), which are in steep decline, and drastically impact the populations of salmon and orca whales, for whom salmon are a primary food source. For years, environmental groups have argued for breaching the dams; other interests counter that the dams are too critical to the economy of the region to lose; and federal agencies assert that the dams can remain and salmon populations will recover with mitigation techniques. Scientific and economic analyses, litigation, and elected officials’ efforts have not been able to move the issue towards a solution. Readers will examine the interests of primary actors in the issue, how they influence the policy process, the role of scientific and economic analyses, and possible approaches for resolving the issue.


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