This study was aimed to gain knowledge on the ontogeny of digestive enzymes in common carp larvae at the governmental Warm water Fish Aquaculture Center of Shahid Rajaee in Sari, Mazandaran, Iran. The ontogenetic development of pancreatic (trypsin, chymotrypsin, lipase and α-amylase) and intestinal (alkaline phosphatase and aminopeptidase-N) enzymes were assessed in common carp larvae from firs...

In kinetoplastids, Euglena, and four metazoan phyla, trans-splicing has been described as a mechanism for the generation of mature messenger RNAs (mRNAs): 5'-ends of precursor mRNAs are replaced by a short spliced leader (SL) exon from a small SL RNA. Although the full phylogenetic range is unknown, trans-splicing has not been found in vertebrates, insects, plants, or yeast. In animal groups wh...

Species of Hexarthra and Polyarthra are freshwater rotifers with well-known escape behaviors that result from interactions with planktonic predators. Both rotifers bear a suite of mobile appendages that function in evasive maneuvers and saltatory jumps through the water column, but the anatomical and functional bases of these actions are poorly understood. Here, we use a combination of phalloid...

Rotifers are useful model organisms for aging research, owing to their small body size (0.1-1 mm), short lifespan (6-14 days) and the relative easy in which aging and senescence phenotypes can be measured. Recent studies have shown that antioxidants can extend the lifespan of rotifers. In this paper, we analyzed changes in the mRNA expression level of genes encoding the antioxidants manganese s...

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...