Spatial and temporal patterns of plankton ciliates species composition in the Paraná River floodplain were investigated. Samplings were carried out in twelve environments in two distinct hydrological periods (limnophase and potamophase). A total of 61 species of ciliates were recorded, and among them 21 are classified as pelagic while 40 are considered preferentially as littoral species. The registered species belong to eleven orders, and among them, Prostomatida was the most specious followed by Hymenostomatida and Peritrichida. The ciliate species composition was significantly distinct between periods, but not among environments. In this way, typically pelagic species characterized the ciliate community during the limnophase period, while the littoral species were predominant during the potamophase period. Our results strongly support the idea of the flood pulse as the main factor driving the composition pattern of the planktonic ciliates community in the Paraná River floodplain.Keywords: planktonic ciliates, species composition, floodplain, Paraná River.Padrões espaciais e temporais da composição de espécies de ciliados (Protozoa: Ciliophora) no plâncton da planície de inundação do Alto Rio Paraná
ResumoNo presente estudo foram investigados os padrões espaciais e temporais da composição de espécies de ciliados planctônicos na planície de inundação do Alto Rio Paraná. As amostras foram obtidas em 12 ambientes, em dois períodos hidrológicos distintos (limnofase e potamofase). Foram registradas 61 espécies de ciliados entre as quais 21 foram classificadas como pelágicas enquanto 40 foram consideradas preferencialmente litorâneas. As espécies registradas pertencem a 11 ordens, sendo Prostomatida foi a mais especiosa, seguida por Hymenostomatida e Peritrichida. A composição de espécies de ciliados foi significativamente distinta entre os períodos hidrológicos, enquanto que entre os ambientes, diferenças na composição não foram evidenciadas. Dessa forma, espécies tipicamente pelágicas caracterizaram a comunidade de ciliados na limnofase, enquanto que espécies litorâneas foram preponderantes para a composição de ciliados na potamofase. Os resultados suportam a idéia do pulso de inundação como principal fator controlador dos padrões de composição da comunidade de ciliados planctônicos na planície de inundação do Alto Rio Paraná.Palavras-chave: ciliados planctônicos, composição de espécies, planície de inundação, Rio Paraná. Pauleto, GM. et al. 518
This study evaluated the influence of rainfall amount on the abundance, species richness, and species occurrence and abundance distribution of the ciliate community associated with the bromeliad Aechmea distichantha. The plants were collected from a rock wall of about 10-km long at the left bank of Paraná River. We assessed the effects of both spatial and temporal variables on the community attributes, as well as whether plants geographically closer have a similar abundance distribution and species composition. The ciliate community was substantially distinct between both hydrological periods, with greater values of species richness and abundance in the rainy period. No spatial structuring (differences in the species occurrence and abundance distribution among strata) or geographical similarity (similarity in ciliate species composition among the plants) was found. Multiple regression analysis showed a positive relationship only between the ciliate abundances and water volumes for both periods. Although few of the formulated predictions were confirmed, our study provides valuable information on the ecological aspects of the ciliate community inhabiting bromeliad phytotelmata.
Background: In this paper, we verified the changes in species composition of the ciliate community inhabiting phytotelmata of tank bromeliads in response to seasonality (rainfall). Plants were located at several heights of a great rocky wall on the left bank of the Parana River, southern Brazil. We also assessed if the heights of the plants in relation to the river influence the ciliate species composition. Thus, samplings were performed in the dry and rainy seasons, in three layers of the rock walls (lower, middle, and upper), with a total of 72 samples in both periods. Results: A relative high number of species and a predominance of hymenostomatids were observed in the sampled plants. Among the recorded species, about 35% occurred exclusively in the dry season. The detrended correspondence analysis demonstrated that the ciliate community changed substantially due to rainfall. However, there was no distinctness in species composition among the strata. In contrast to expectations, the number of species recorded in the dry season was greater than that recorded in the rainy season, refuting the hypothesis that the precipitation volume favors an increase in the number of species. Conclusions: The rainfall is, undoubtedly, the main factor structuring the community and determining the ciliate species composition in the phytotelmata of the bromeliads. We found that the closeness of the plants with the river is also an important factor for the structuration of the community, due to the dispersion of organisms from the river to the tanks. The occurrence and predominance of planktonic species in the plants at the lower stratum and soil species at the higher stratum indicates a great influence of the neighboring environments on the ciliate community inhabiting the phytotelmata.
Phytotelmata are vegetal structures that hold water from the rain, and organic matter from the forest and the soil, resulting in small, compartmentalized bodies of water, which provide an essential environment for the establishment and development of many organisms. These microenvironments generally harbor endemic species, but many organisms that are found in lakes and rivers, are also present. Here, we report, for the first time, the occurrence of the ciliate genus Paramecium in the tank of the bromeliad species Aechmaea distichantha. The identification of the Paramecium species was performed based on live observations, protargol impregnation, scanning electronic microscopy, and sequencing of the 18s rRNA. The absence of Paramecium from bromeliad tank water was highlighted in several earlier investigations, and may be due to the fact that this species is unable to make cysts. The occurrence of Paramecium multimicronucleatum in our samples may be explained by the proximity between the bromeliads and the river, a potential source of the species. Further, we also believe that the counting methodology used in our study provides a more accurate analysis of the species diversity, since we investigated all samples within a maximum period of 6 h after sampling, allowing minimum loss of specimens.
This study examined temporal and spatial (vertical) variations of composition, richness and abundance of the planktonic ciliates community in an urban and eutrophic lake, as well as identified the limnological factors involved in determining the patterns observed. To this end, samples of ciliates and measures of limnological variables were taken at different depths and hydrological periods. 35 ciliate species were identified, among which 14 species occurred in all periods and strata, being Prostomatida the most specious, followed by Gymnostomatida, Oligotrichida, Peritrichida, and Scuticociliatida. The patterns found for composition, abundance and species richness evidenced a vertical and temporal variation of these attributes. However, in general the composition and species richness have varied more along the vertical gradient than between periods, whereas for the abundance, only temporal differences could be detected. Results observed herein indicated that benthic species seem to be mainly influenced by the amount of organic matter, phosphorus and ammonia, while planktonic ones, abundant at the surface, were mainly associated with higher dissolved oxygen concentrations. In this way, seasonal and vertical variations of limnological characteristics were decisive for the patterns of occurrence and abundance of ciliate species.
The biodiversity and biogeography of protists inhabiting many ecosystems have been intensely studied using different sequencing approaches, but tropical ecosystems are relatively under-studied. Here, we sampled planktonic waters from 32 lakes associated with four different river-floodplains systems in Brazil, and sequenced the DNA using a metabarcoding approach with general eukaryotic primers. The lakes were dominated by the largely free-living Discoba (mostly the Euglenida), Ciliophora, and Ochrophyta. There was low community similarity between lakes even within the same river-floodplain. The protists inhabiting these floodplain systems comprise part of the large and relatively undiscovered diversity in the tropics.
scite is a Brooklyn-based startup that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.