First report of an epibiotic relationship between ciliates and planktonic copepods in a Brazilian floodplain

The peritrich ciliates are a widely distributed group of protozoa and include stalked and sedentary organisms, which may be solitary or colonial. These organisms are often observed as part of a relationship entitled epibiosis. This relationship is a facultative association between two organisms: the epibiont, which colonizes the surface of living substrates, and the basibiont, which hosts the epibionts. During a survey on the epibiotic relationship between ciliates e copepods in upper Paraná River floodplain-PR/MS Brazil, samples were taken in different types of environments (three rivers, three canals, 16 connected and 14 unconnected lakes), in a total of 36 sampling sites. Among these environments, 22 showed copepods infested by epibiont ciliates. The copepods Thermocyclops decipiens, Thermocyclops minutus and Notodiaptomus amazonicuswhere colonized by epibiont ciliates from the genus Epistylis.In this study, we reported for the first time, epibiosis in a Brazilian floodplain.(AU)

First report of an epibiotic relationship between ciliates and planktonic copepods in a Brazilian floodplain

The peritrich ciliates are a widely distributed group of protozoa and include stalked and sedentary organisms, which may be solitary or colonial. These organisms are often observed as part of a relationship entitled epibiosis. This relationship is a facultative association between two organisms: the epibiont, which colonizes the surface of living substrates, and the basibiont, which hosts the epibionts. During a survey on the epibiotic relationship between ciliates e copepods in upper Paraná River floodplain-PR/MS Brazil, samples were taken in different types of environments (three rivers, three canals, 16 connected and 14 unconnected lakes), in a total of 36 sampling sites. Among these environments, 22 showed copepods infested by epibiont ciliates. The copepods Thermocyclops decipiens, Thermocyclops minutus and Notodiaptomus amazonicuswhere colonized by epibiont ciliates from the genus Epistylis.In this study, we reported for the first time, epibiosis in a Brazilian floodplain.

Structure of planktonic ciliates community (Protist, Ciliophora) from an urban lake of southern Brazil / Estrutura da comunidade de ciliados planctônicos (Protista, Ciliophora) de um lago urbano do Sul do Brasil

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.

O presente estudo teve como objetivo investigar as variações temporais e espaciais (vertical) da composição, riqueza de espécies e abundância da comunidade de ciliados planctônicos em um lago urbano, eutrófico, e identificar alguns fatores limnológicos intervenientes na determinação dos padrões observados. Para tal, amostras de ciliados, bem como as mensurações das variáveis limnológicas foram obtidas em diferentes profundidades e períodos hidrológicos. Trinta e cinco espécies de ciliados foram identificadas, das quais 14 ocorreram em ambos os períodos e estratos. Prostomatida foi a ordem com maior número de espécies, seguida por Gymnostomatida, Oligotrichida, Peritrichida e Scuticociliatida. A composição e riqueza de espécies, em geral, variaram mais verticalmente que temporalmente, enquanto que para a abundância, diferenças foram observadas apenas entre os períodos hidrológicos Os resultados indicaram que espécies bentônicas parecem ser influenciadas principalmente pela quantidade de matéria orgânica, fósforo total e amônia, enquanto que as espécies planctônicas, abundantes na superfície, estiveram principalmente associadas com as maiores concentrações de oxigênio dissolvido. Desta forma, as variações sazonais e verticais das características limnológicas foram decisivas na determinação dos padrões de ocorrência e abundância de espécies de ciliados.