Abstract
We analyzed the genetic diversity (V4 region of the 18S rRNA) of planktonic microbial eukaryotes in four high mountain lakes including two remote biogeographic regions (the Himalayan mountains and the European Alps) and distinct habitat types (clear and glacier-fed turbid lakes). The recorded high genetic diversity in these lakes was far beyond of what is described from high mountain lake plankton. In total, we detected representatives from 66 families with the main taxon groups being Alveolata (55.0% OTUs97%, operational taxonomic units), Stramenopiles (34.0% OTUs97%), Cryptophyta (4.0% OTUs97%), Chloroplastida (3.6% OTUs97%) and Fungi (1.7% OTUs97%). Centrohelida, Choanomonada, Rhizaria, Katablepharidae and Telonema were represented by <1% OTUs97%. Himalayan lakes harbored a higher plankton diversity compared to the Alpine lakes (Shannon index). Community structures were significantly different between lake types and biogeographic regions (Fisher exact test, P < 0.01). Network analysis revealed that more families of the Chloroplastida (10 vs 5) and the Stramenopiles (14 vs 8) were found in the Himalayan lakes than in the Alpine lakes and none of the fungal families was shared between them. Biogeographic aspects as well as ecological factors such as water turbidity may structure the microbial eukaryote plankton communities in such remote lakes.
Highlights
In the last years, molecular tools have seized biodiversity studies, and next-generation sequencing (NGS) approaches have become popular instruments to estimate protist diversity (Margulies et al, 2005)
The nitrate (NO3-N) values were generally higher in the Alpine lakes than in the Himalayan ones
Conductivity and dissolved organic carbon (DOC) concentrations were higher than in the turbid lakes and the concentrations of total phosphorus (TP) and the pH were lower in the clear lakes, with the highest TP concentration observed in FAS 3 (Table 1)
Summary
Molecular tools have seized biodiversity studies, and next-generation sequencing (NGS) approaches have become popular instruments to estimate protist diversity (Margulies et al, 2005). Alexander et al, 2009; Stoeck et al, 2010; Edgcomb et al, 2011; Bik et al, 2012; Stock et al, 2012). Received: 17 September 2014; Accepted: 21 January 2015 C FEMS 2015. Hitherto only very few sequence data are available from protistan plankton in high mountain lakes (e.g. Triado -Margarit and Casamayor 2012). These data emphasized high mountain lakes as diversity hotspots for (hitherto unknown) eukaryotic microbial plankton. Such a scarce knowledge on microbial eukaryotic plankton in high mountain lakes is unsatisfying considering the ecological importance of these organisms in the energy and carbon transfer within aquatic food webs (e.g. Azam et al, 1983; Sherr and Sherr 1988; Weisse and Muller 1998; Sonntag et al, 2006; Zingel et al, 2007)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
