Seasonal and annual population dynamics of ciliates in a shallow eutrophic lake

The trophic role and impact of plankton ciliates in the microbial web structure of a tropical polymictic lake dominated by filamentous cyanobacteria

“…Therefore, the nanociliate abundance increased during the rainy season (third survey) when the bacteria, picocyanobacteria and filamentous cyanobacteria were least abundant. This apparent lack of correlation is inconsistent with what occurs in bottom-up-regulated ecosystems (by resources) (Auer et al, 2004;Zingel and Nõges, 2010), where significant correlations are found among ciliates and chlorophyll a or picoplankton densities. However, a careful follow-up of the nanociliate and picoplankton densities for several days would be necessary to determine if top-down control actually prevails or if the observed pattern observed was a result of picoplankton depletion by nanociliates.…”

“…These findings may generalize to an almost cosmopolitan distribution throughout these aquatic systems (Pfister et al, 2002). Several of the observed morphotypes, such Uronema, Cyclidium, Rimostrombidium (Šimek et al, 1995;Zingel et al, 2007), Mesodinium, Colpoda (Foissner et al, 1999;Zingel and Nõges, 2010), and Halteria (Šimek et al, 1995), graze on picoplankton, these may include nanociliates which play an important role in energy and matter transfer through the microbial web because of the high metabolic rates associated with their small size.…”

“…Several of the genera mentioned thus far have also been reported to graze on microalgae, such as Halteria, Mesodinium, Rimostrombidium, Limnostrombidium and Pelagostrombidium (Foissner et al, 1999;Zingel and Nõges, 2010), as well as certain larger ciliates, such as Bursaridium, and Linostomella, the latter of which is a particularly voracious grazer upon the chain-forming A. granulata and small pennate diatoms. Predatory forms, such as Paradileptus and Litonotus, were also found.…”

“…The ciliate assemblages also contained Actinobolina, Belonophrya, Mesodinium, Monodinium, and Lagynophrya, which prey on smaller protists, including ciliates (Foissner et al, 1999;Jürgens et al, 1999b;Zingel and Nõges, 2010). Several of the genera mentioned thus far have also been reported to graze on microalgae, such as Halteria, Mesodinium, Rimostrombidium, Limnostrombidium and Pelagostrombidium (Foissner et al, 1999;Zingel and Nõges, 2010), as well as certain larger ciliates, such as Bursaridium, and Linostomella, the latter of which is a particularly voracious grazer upon the chain-forming A. granulata and small pennate diatoms.…”

“…Moreover, the ciliate importance to the food web increases with higher primary productivity (Sherr and Sherr, 2002), although it remains to be shown if this relationship holds true for tropical lakes, such as Catemaco. The nature of lacustrine trophic microbial web components and their interactions have been studied for temperate lakes with different trophic statuses (Straškrabová et al, 1999;Pfister et al, 2002;Auer et al, 2004;Chróst et al, 2009;Agasild et al, 2013;Van Wichelen et al, 2013), including eutrophic temperate lakes affected by cyanobacterial blooms (Moustaka-Gouni et al, 2006;Zingel et al, 2007;Zingel and Nõges, 2010), shallow soda lakes of Africa (Burian et al, 2013), relatively shallow eutrophic lakes, deep oligotrophic tropical lakes of Eastern Africa (Yasindi and Taylor, 2003), deep athalassohaline lakes of North America Peštová et al, 2008), and shallow subtropical lakes with differing trophic statuses (Beaver and Crisman, 1989;Beaver and Crisman, 1990;Gomes and Godinho, 2003;MachadoVelho et al, 2005;Havens et al, 2007;Bagatini et al, 2013;Machado-Velho et al, 2013). These studies have demonstrated that microbial food webs, particularly the composition, abundance, biomass and diversity of ciliates, present specific responses to the geographic, climatic and ecological features of different lakes and reservoirs.…”