New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Rotifer

The rotifers make up a phylum of microscopic, and near-microscopic pseudocoelomate animals. 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. 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. About 25 species are colonial, either sessile or planktonic. 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.

Related Stories
 


Plants & Animals News

August 27, 2025

Even sharks’ famous tooth-regrowing ability may not save them from ocean acidification. Researchers found that future acidic waters cause shark teeth to corrode, crack, and weaken, threatening their effectiveness as hunting weapons and ...
Ripple bugs’ fan-like legs inspired engineers to build the Rhagobot, a tiny robot with self-morphing fans. By mimicking these insects’ passive, ultra-fast movements, the robot gains speed, control, and endurance without extra ...
Researchers discovered that bees use flight movements to sharpen brain signals, enabling them to recognize patterns with remarkable accuracy. A digital model of their brain shows that this movement-based perception could revolutionize AI and ...
A new study reveals that the majority of Earth’s species stem from a few evolutionary explosions, where new traits or habitats sparked rapid diversification. From flowers to birds, these bursts explain most of the planet’s ...
Scientists have uncovered a startling split in the venom of Australia’s Eastern Brown Snake. In the south, bites cause rock-solid blood clots, while in the north, they trigger flimsy clots that ...
Planting more trees can help cool the planet and reduce fire risk—but where they are planted matters. According to UC Riverside researchers, tropical regions provide the most powerful climate benefits because trees there grow year-round, absorb ...
Kelp forests bounce back faster from marine heatwaves when shielded inside Marine Protected Areas. UCLA researchers found that fishing restrictions and predator protection strengthen ecosystem resilience, though results vary by ...
MSU researchers discovered that microbes begin shaping the brain while still in the womb, influencing neurons in a region critical for stress and social behavior. Their findings suggest modern birth practices that alter the microbiome may have ...
NASA-backed simulations reveal that meltwater from Greenland’s Jakobshavn Glacier lifts deep-ocean nutrients to the surface, sparking large summer blooms of phytoplankton that feed the Arctic food ...
Roughly two-thirds of all atmospheric methane, a potent greenhouse gas, comes from methanogens. Tracking down which methanogens in which environment produce methane with a specific isotope signature is difficult, however. UC Berkeley researchers ...
Scientists have engineered a groundbreaking cancer treatment that uses bacteria to smuggle viruses directly into tumors, bypassing the immune system and delivering a powerful one-two punch against cancer cells. The bacteria act like Trojan horses, ...
Weaver ants have cracked a teamwork puzzle that humans have struggled with for over a century — instead of slacking off as their group grows, they work harder. These tiny architects not only build elaborate leaf nests but also double their pulling ...

Latest Headlines

updated 12:56 pm ET