The rotifers make up a phylum of microscopic, and near-microscopic pseudocoelomate animals. They were first described by John Harris in 1696 (Hudson and Gosse, 1886). Leeuwenhoek is mistakenly given credit for being the first to describe rotifers but Harris had produced sketches in 1703. Most rotifers are around 0.1-0.5 mm long, and are common in freshwater throughout the world with a few saltwater species.

Rotifers get their name (derived from Latin and meaning "wheel-bearer"; they have also been called wheel animalcules) from the corona, which is composed of several ciliated tufts around the mouth that in motion resemble a wheel. These create a current that sweeps food into the mouth, where it is chewed up by a characteristic pharynx (mastax) containing tiny jaws. It also pulls the animal, when unattached, through the water. Most free-living forms have pairs of posterior toes to anchor themselves while feeding.

There are a variety of different shapes of rotifer. There is a well-developed cuticle which may be thick and rigid, giving the animal a box-like shape, or flexible, giving the animal a worm-like shape; such rotifers are respecitvely called loricate and illoricate. Many rotifers swim, and some illoricate forms move by inchworming along the substrate. Other rotifers are sessile, living inside tubes or gelatinous holdfasts. About 25 species are colonial (i.e. Sinantherina semibullata), either sessile or planktonic. Like many other microscopic animals, adult rotifers frequently exhibit eutely - they have a fixed number of cells within a species, usually on the order of one thousand.

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PLoS Medicine: New Articles

PLoS Medicine Issue Image | Vol. 6(6) June 2009
Tue, 30 Jun 2009 07:00:00 -0000
Clean water should be recognized as a human right. At the March 2009 United Nations meetings coinciding with the World Water Forum, a declaration that would recognize water as a basic human right was defeated. In this month's Editorial, the PLoS Medicine Editors argue that access to clean water should be declared a basic human right for three reasons. First, access to clean water can substantially reduce the global burden of disease caused by water-borne infections. Second, the privatization of water—as witnessed in Bolivia, Ghana, and other countries—has not effectively served the poor, who suffer the most from lack of access to clean water. Third, the prospect of global water scarcity—exacerbated by climate change, industrial pollution, and population growth—means that no country is immune to a water crisis.Image Credit: Rudhach at flickr.com
Seasonal Hunger: A Neglected Problem with Proven Solutions
Bapu Vaitla et al. Tue, 30 Jun 2009 07:00:00 -0000
Clean Water Should Be Recognized as a Human Right
Tue, 30 Jun 2009 07:00:00 -0000
Can We “Hedge” against the Development of Antiviral Resistance among Pandemic Influenza Viruses?
David K. Shay et al. Tue, 30 Jun 2009 07:00:00 -0000
David K. Shay and Benjamin Ridenhour discuss a modeling study predicting that stockpiling a secondary antiviral for use early in a flu pandemic can forestall resistance to the primary stockpiled drug.
Pralidoxime in Acute Organophosphorus Insecticide Poisoning—A Randomised Controlled Trial
Michael Eddleston et al. Tue, 30 Jun 2009 07:00:00 -0000
In a randomized controlled trial of individuals who had taken organophosphorus insecticides, Michael Eddleston and colleagues find that there is no evidence that the addition of the antidote pralidoxime offers benefit over atropine and supportive care.
What Is the Optimal Therapy for Patients with H5N1 Influenza?
Nicholas J. White et al. Tue, 23 Jun 2009 07:00:00 -0000
Nicholas White discusses optimal dosing of oseltamivir, Robert Webster and Elena Govorkova discuss combination antiviral therapy, and Timothy Uyeki discusses clinical care of patients with H5N1.

EurekAlert! - Biology

Study identifies how tamoxifen stimulates uterine cell growth and cancer
Thu, 02 Jul 2009 00:00:00 -0400
(University of California - San Francisco) University of California - San Francisco researchers have identified a new "feed-forward" pathway linking estrogen receptors in the membrane of the uterus to a process that increases local estrogen levels and promotes cell growth.
'Genetic arms race' between bacteria, viruses subject of stimulus grant
Thu, 02 Jul 2009 00:00:00 -0400
(Michigan State University) The oceans teem with microscopic bacteria that produce much of Earth's oxygen as they absorb carbon dioxide greenhouse gas. But fast-mutating viruses also populate the seas, attacking marine bacteria in an ages-old evolutionary arms race. A Michigan State University researcher will probe that ancient dynamic against the backdrop of environmental and climate change, and the pivotal role played by aquatic bacteria in maintaining the Earth's biological balance.
Learning from locusts
Thu, 02 Jul 2009 00:00:00 -0400
(Queen's University) A similarity in brain disturbance between insects and people suffering from migraines, stroke and epilepsy points the way toward new drug therapies to address these conditions.

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