Browsing by Author "Luo, Wei"

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    Food algae for Lesser Flamingos: a stocktaking
    (Springer, 2016-07) Krienitz, Lothar; Krienitz, Doris; Dadheech, Pawan K.; Hübener, Thomas; Kotut, Kiplagat; Luo, Wei; Teubner, Katrin; Versfeld, Wilferd D.
    Lesser Flamingo, the flagship species of saline wetlands of Africa and India, is a specialised feeder subsisting on microscopic cyanobacteria and algae. To establish the relationship between flamingo occurrence and food algal abundance and quality, an extensive microphyte survey in more than 150 sampling trips to seven countries over a 15-years period (2001–2015) was carried out. The 44 habitat sites included the core soda lakes in eastern Africa (Bogoria, Nakuru, Elmentaita, Oloidien), where the highest numbers of flamingos were observed, and five breeding sites in eastern and southern Africa as well as in north-western India. A reference describing the diversity of microphytes was established including members of three orders of cyanobacteria and nine orders of eukaryotic algae that potentially could act as food source for Lesser Flamingos. Preferred food organisms consisted of filamentous cyanobacteria, mainly Arthrospira, as well as benthic diatoms. Further investigation on the suitability of other microphytes as alternative flamingo diet revealed the food potential of chlorophytes and euglenophytes. This paper discusses a phycological perspective in the feeding ecology of Lesser Flamingos. The survey findings can assist scientists and conservationists in evaluating the potential of wetlands to support flocks of this endangered bird.
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    Hidden diversity of eukaryotic plankton in the soda lake Nakuru, Kenya, during a phase of low salinity revealed by a SSU rRNA gene clone library
    (Springer, 2013) Luo, Wei; Kotut, Kiplagat; Krienitz, L.
    A SSU rRNA gene clone library was constructed to establish the diversity of eukaryotic plankton in the African soda lake Nakuru during a phase of low salinity (9.7 ppt = hyposaline). Normally, the lake is mesosaline (up to 50 ppt) and its phytoplankton is dominated by few species of cyanobacteria, in particular Arthrospira fusiformis, which is the main food resource of Lesser Flamingos. Our study recovered a unique phytoplankton species composition characterized by a high diversity of monadoid and coccoid green algae. Out of 77 clones detected, 52 belonged to Chlorophyta. Many of the chlorophytes were transported from the catchment area into the lake through small seasonal rivers and an outflow of the Nakuru town sewage treatment plant. Other phylogenetic groups detected were Fungi, Cryptophyta, Jakobida, Alveolata, Stramenopiles, and Metazoa. Our findings reveal a hidden diversity, which would not have been detected by traditional observations.
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    Molecular diversity of plankton in a tropical crater lake switching from hyposaline to subsaline conditions: Lake Oloidien, Kenya
    (Springer, 2016-09) Kotut, Kiplagat; Luo, Wei; Li, Huirong; Krienitz, Lothar
    Salinity in the climate sensitive tropical endorheic crater lake Oloidien (Great African Rift Valley, Kenya) decreased from hyposaline to subsaline conditions during the period 2010–2015. The change in salinity was accompanied by a pronounced change in planktonic life forms—from blooms of the cyanobacterium Arthrospira supporting tens of thousands of Lesser Flamingos to highly diverse communities of cyanobacteria and algae which do not sustain the consumer birds. Besides the well-known macroand microscopic lake life, a hidden diversity of microorganisms was detected using molecular methods. SSU rRNA gene clone libraries and data from Ilumina Miseq sequencing of samples collected at the two contrasting stages revealed distinct and highly diverse microbial communities. Different bacterial clades dominated the two samples. In 2011, Firmicutes (class Bacilli) whose origin was the fecal waste of birds were the dominant group. However, the Cyanobacteria and Chloroflexi were the most prevalent in 2015. From the microbial eukaryote samples obtained in 2011, rotifers and ciliates that feed on Arthrospira and rich bacterial food dominated the plankton, while the cryptophytes were the most prevalent in 2015. On the two occasions, a mixture of organisms previously not known to occur in saline or in freshwater habitats was found.
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    Picocystis salinarum (Chlorophyta) in saline lakes and hot springs of East Africa.
    (2012-01) Krienitz, L.; Bock, Christina; Kotut, Kiplagat; Luo, Wei
    The occurrence of Picocystis salinarum in saline inland waters of East Africa was investigated using a polyphasic approach of small-subunit (SSU) rDNA phylogeny and light microscope observations. Recent studies have found that Picocystis occasionally replaces the dominant cyanobacterium (Arthrospira fusiformis), which is the main food resource of Lesser Flamingos, in soda lakes of Bogoria and Nakuru. This article discusses the consequences of a high abundance (maximum cell numbers of > 3 billion cells l−1) of Picocystis on food chains of African saline waters. During the study, we found a new morphotype of Picocystis characterized by larger cell sizes and absence of lobes in hot springs near Lake Magadi. SSU rRNA genes of Picocystis strains and uncultured field clones collected from Lake Nakuru were subjected to phylogenetic analyses together with other picoplankton from field and culture samples from saline, marine or freshwater. Picocystis salinarum from saline inland waters represents a link between marine and freshwater habitats from both an ecological and a phylogenetic point of view and is therefore of great interest.