Seasonal variations of zooplankton communities were studied in the southern Caspian Sea for 4 successive seasons and 8 transects with 5 stations from 5 to 100 m depths which sampled during 2009. The zooplankton population constituted of 73.33% copepods, 24.21% rotifers, 2.23% cladocerans and 0.23% protozoans. Copepods were dominant at all stations with a density between 1456±531 ind. m-3 (Trans...

We examined population growth rate, reproduction and phosphatase activity in digestive tracts of individual Brachionus calyciflorus fed by P-replete (molar C:P 1⁄4 107) or P-depleted (C:P 1⁄4 920) algal food supplied at three carbon (C) concentrations (1, 2, and 4 mg C L). Rotifer growth rate was significantly influenced by P content, whereas the effect of algal C concentration was not signific...

Many eukaryotes share a common response to environmental stresses. The responses include reorganization of cellular organelles and proteins. Similar stress responses between divergent species suggest that these protective mechanisms may have evolved early and been retained from the earliest eukaryotic ancestors. Many eukaryotic cells have the capacity to sequester proteins and mRNAs into transi...

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 Class Bdelloidea of the Phylum Rotifera is the largest metazoan taxon in which males, hermaphrodites, and meiosis are unknown. We conducted a molecular genetic test of this indication that bdelloid rotifers may have evolved without sexual reproduction or genetic exchange. The test is based on the expectation that after millions of years without these processes, genomes will no longer contai...

Zooplankton communities were investigated in a turbid shallow lake with an aim to analyze (i) relationships between ecological conditions and the communities and (ii) trophic state inferred from abiotic and biotic indicators. According to results emerged littoral vegetated zone increased diversity (30 taxa) in comparison to the pelagial (17 taxa). Rotifers dominated in terms of diversity and ab...

A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensit...

An extreme radiation of hundreds species different groups animals occurred in Lake Baikal, Siberia, Russia; among them, amphipods represent one the most remarkable invertebrates with about 350 endemic species. Amphipods host associated epibiont rotifers, and aim study is to explore possibility that bdelloid rotifers living as epibionts on Baikal coevolved their hosts diversified species-specifi...

Rotifers of Class Bdelloidea are common freshwater invertebrates of ancient origin whose apparent asexuality has posed a challenge to the view that sexual reproduction is essential for long-term evolutionary success in eukaryotes and to hypotheses for the advantage of sex. The possibility nevertheless exists that bdelloids reproduce sexually under unknown or inadequately investigated conditions...