Rotifers represent an important component of freshwater zooplankton. The high richness taxa, particularly in littoral macrophyte zones water bodies tropical and subtropical flood-prone areas, is a repeatedly reported fact. However, studies on the composition periphytic rotifers Neotropics are reduced almost non-existent some regions. A qualitative study (Monogononta) associated with aquatic veg...

BACKGROUND The mortality rates of older people changes with the seasons. However, it has not been properly investigated whether the seasons affect medical care expenditure (MCE) and institutionalization. Seasonal variation in MCE is plausible, as MCE rises exponentially before death. It is therefore important to investigate the impact of the seasons on MCE both mediated and unmediated by mortal...

Investigating the seasonal asymmetry of violent behaviour has a long history. Despite this, there still remains considerable debate about the nature and aetiology of this phenomenon. Reports on homicide, for example, are mixed: some have found homicide seasonality but most have not. In contrast, all published studies on assault report that this behaviour is seasonal. Moreover, only two studies,...

Seasonal declines in avian clutch size are well documented, but seasonal variation in other reproductive parameters has received less attention. For example, the probability of complete brood mortality typically explains much of the variation in reproductive success and often varies seasonally, but we know little about the underlying cause of that variation. This oversight is surprising given t...

Little information is known about bioaccumulation of atrazine or the effects it has on consumers that ingest atrazine-contaminated prey. For that reason, freshwater microalgae Chlorella vulgaris cultures were exposed to different concentrations of atrazine for twenty-four hours and were then used as an exclusive food source for Brachionus calyciflorus for three days with the intent to evaluate ...

Members of the ciliate group of protozoans are often observed in mass cultures of rotifers. In particular, Euplotes and Vorticella are common contaminating species. In this study, I examined the effect of the ciliates Euplotes sp. and Vorticella sp. on the growth of the rotifer Brachionus rotundiformis by conducting inter-specific and tripartite-specific mixed-culture experiments. The growth of...

Using the marine rotifer Brachionus plicatilis acute toxicity tests, we estimated the toxicity of Corexit 9500A(®), propylene glycol, and Macondo oil. Ratios of 1:10, 1:50 and 1:130 for Corexit 9500A(®):Macondo oil mixture represent: maximum exposure concentrations, recommended ratios for deploying Corexit (1:10-1:50), 1:130 the actual dispersant:oil ratio used in the Deep Water Horizon spill. ...