In the present study, two small lakes on the margins of the River Cuiabá were analyzed regarding taxonomic composition and population densities of the zooplankton. Diversity was evaluated for two groups, Rotifera and Cladocera; sampling was carried out on two dates: 2 March 1999, in the rainy season, and 25 August 1999, in the dry season. Seventy-nine rotifer taxa, 30 cladoceran taxa, and 6 cop...

Two Iranian strains of Brachionus rotifers were cultured under different food and salinity regimes. The rotifers were fed with five algal types (freshwater and marine Chlorella vulgaris, Nannochloropsis occulata, Isochrysis galbana and Scenedesmus obliquus) at three different salinities (5, 15 and 25 g/L) and their reproductive and growth parameters were assessed. The maximum number of ovigerou...

Axenic rotifers were cultured under synxenic conditions on a bacteria-free artificial diet. The cultures were inoculated either with one of four strains of cultured marine bacteria, or with mixtures of bacteria made up with the same four strains and differing only in the proportions of cells from each strain within the blends. Control cultures were inoculated with bacteria present in Ž . freshl...

BACKGROUND Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scar...

The oomycete genus Aquastella is described to accommodate two new species of parasites of rotifers observed in Brooktrout Lake, New York State, USA. Three rotifer species--Keratella taurocephala, Polyarthra vulgaris, and Ploesoma truncatum--were infected, and this is the first report of oomycete infection in these species. Aquastella attenuata was specific to K. taurocephala and Aquastella acic...

Rotifers have attracted the attention of biologists for well over 200 years. Interest in these exquisite animals rests in their diverse morphology, short generation time resulting in high growth rates, ability to withstand desiccation, and wide distribution, coupled with evidence of cryptic speciation. Moreover, three modes of reproduction are present in the phylum: obligatory sexuality, cyclic...

Copepods have often improved larviculture of marine fish species that are not easily reared using rotifers. One such species is Glaucosoma hebraicum. G. hebraicum larvae were reared on a combined diet consisting of equal numbers of cultured copepod nauplii and rotifers and a diet of rotifers only. Growth was significantly greater in larvae fed with the combined diet. Survival was 37% in the cop...

Although numerous hypotheses exist to explain the overwhelming presence of sexual reproduction across the tree of life, we still cannot explain its prevalence when considering all inherent costs involved. The Red Queen hypothesis states that sex is maintained because it can create novel genotypes with a selective advantage. This occurs when the interactions between species induce frequent envir...

Rotifers have attracted the attention of biologists for well over 200 years. Interest in these exquisite animals rests in their diverse morphology, short generation time resulting in high growth rates, ability to withstand desiccation, and wide distribution, coupled with evidence of cryptic speciation. Moreover, three modes of reproduction are present in the phylum: obligatory sexuality, cyclic...

Species distribution models (SDMs) are a general suite of models that relate the frequency of species occurrences (presence only or presence/absence) to sets of environmental variables. These relationships can then be used to generate predictions of the geographic areas where the species are expected to occur, making SDMs powerful and widely used tools in conservation biology, biogeography and ...