Rotatoris

Rotatoris is a genus of microscopic aquatic invertebrates in the phylum Rotifera. Members of this genus are small, transparent planktonic organisms typically measuring 150 to 300 micrometers in length. The body bears a frontal corona composed of ciliated lobes that enable suspension feeding and may exhibit rapid circular motion during prey capture. A compact mastax provides chewing action on diatoms, algae, and detritus. The elongated foot ends in adhesive toes that allow temporary attachment to submerged surfaces.

Distribution and habitat: Rotatoris species occur in freshwater lakes, ponds, and slow-moving streams across temperate and tropical regions. Some species tolerate brackish water, expanding their range to estuarine habitats.

Life cycle and reproduction: Reproduction is predominantly parthenogenetic, with amictic females producing diploid daughters asexually. In response to environmental stress or crowding, sexual reproduction may occur, yielding resting eggs that resist desiccation and cold.

Ecology and significance: As part of the microzooplankton, Rotatoris contributes to nutrient cycling by grazing microalgae. They serve as prey for small crustaceans and larval insects, forming a link in freshwater food webs. Their presence is used as an indicator of water quality in some studies.

Taxonomy and nomenclature: The genus Rotatoris was established to reflect the distinctive rotating motion of the corona observed in species during feeding. The name derives from Latin rota, wheel, plus -oris, a Latin possessive suffix.

See also: Rotifera, microzooplankton.