Animal

Most species of the rotifers are cosmopolitan, but there are also some endemic species, like Cephalodella vittata to Lake Baikal….Rotifer.

Rotifers are thus multicellular creatures who make make their living at the scale of unicellular protists. The name “rotifer” is derived from the Latin word meaning “wheel-bearer”; this makes reference to the crown of cilia around the mouth of the rotifer.

Background. Although prevalent in prokaryotes, horizontal gene transfer (HGT) is rarer in multicellular eukaryotes. Bdelloid rotifers are microscopic animals that contain a higher proportion of horizontally transferred, non-metazoan genes in their genomes than typical of animals.

Innate immune system of bdelloid rotifers.

When viewed under a microscope, there is something that looks rather a lot like a beating heart. However, this is actually a unique muscular pharynx known as a mastax containing structures known as trophi.

Radioactive danger If you think of DNA as a recipe book for the various parts of a living thing, the double-stranded DNA breaks that are caused by ionising radiation are like tearing the book up into small chunks. Absorbed doses of radiation are measured in Grays and ten of these are more than enough to kill a human.

There are no known adverse effects of rotifers on humans.

Every rotifer has eyes and ocelli. Most frequently, there is one eye on the brain and two anterior ocelli in the rotatory apparatus.

Most rotifers are around 0.1-0.5 mm long, and are common in freshwater throughout the world with a few saltwater species. Rotifers may be free swimming and truly planktonic, others move by inchworming along the substrate whilst some are sessile, living inside tubes or gelatinous holdfasts.

Essentially when environmental conditions are good, female rotifers produce up to 7 eggs simultaneously, without any genetic help from a male rotifer. These eggs are genetically identical, and will hatch to form new “daughter” rotifers with in 12-hrs.

Rotifers in the wild have little significance to humans. They may have some economic significance, however, because many species are cultured as a food source for aquariums and cultured filter-feeding invertebrates and fish fry. They also may be used as biological pollution indicators.

Scientists have discovered and purified a substance made by rotifers that can paralyze the worms that cause schistosomiasis, a dangerous infection that affects 200 million people worldwide.

Rotifers are important in freshwater environments due to having one of the highest reproductive rate among metazoans, thus obtaining high population densities in short times, being dominant in many zooplanktonic communities. They act as links between the microbial community and the higher trophic levels.

Although common in freshwater on all continents, some species occur in salt water or brackish water, whereas others live in damp moss or lichens. Most are free-living; some are parasitic. Most live as individuals, but a few species form colonies. Most rotifers are only 0.1 to 0.5 mm (0.004 to 0.02 inch) long.

Most rotifers are free-living. They can swim or walk by anchoring their feet.

Most rotifers have no true cuticle and do not moult. The life cycle is typically a few days to two weeks, but eggs may be produced as little as two days after the parent itself hatched. The maximum life span is about two months.

We demonstrated that zebra mussels Dreissena polymorpha collected from the Hudson River could consume two rotifer species that were common before the zebra mussel invasion. The ingestion rates (biomass of rotifers per hour) for the two rotifer species also differed, but both increased with increasing rotifer density.

Are zebra mussels edible? Most clams and mussels are edible, but that does not mean they taste good! Many species and fish and ducks eat zebra mussels, so they are not harmful in that sense. Therefore to be safe, it is not recommend they be eaten by people.

The dreaded zebra mussel — an invasive species — is killing off native species in lakes and rivers all over the country. But in Lake Ontario, it turns out the zebra mussel has had a positive impact for salmon fishermen. It’s producing fatter, faster-growing salmon.