Rotifera Temporal range:
Possible Devonian and Permian records | |
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Bdelloid rotifer (Bdelloidea) | |
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Pulchritia dorsicornuta (Monogononta) | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Clade: | Bilateria |
Clade: | Nephrozoa |
(unranked): | Protostomia |
(unranked): | Spiralia |
Clade: | Gnathifera |
Phylum: | Rotifera Cuvier, 1798 |
Classes and other subgroups | |
The rotifers (/ˈroʊtɪfərz/, from the Latin rota, "wheel", and -fer, "bearing"), commonly called wheel animals or wheel animalcules,[1] make up a phylum (Rotifera /roʊˈtɪfərə/) of microscopic and near-microscopic pseudocoelomate animals.
They were first described by Rev. John Harris in 1696, and other forms were described by Antonie van Leeuwenhoek in 1703.[2] Most rotifers are around 0.1–0.5 mm (0.0039–0.0197 in) long (although their size can range from 50 μm (0.0020 in) to over 2 mm (0.079 in)),[1] and are common in freshwater environments throughout the world with a few saltwater species.
Some rotifers are free swimming and truly planktonic, others move by inchworming along a substrate, and some are sessile, living inside tubes or gelatinous holdfasts that are attached to a substrate. About 25 species are colonial (e.g., Sinantherina semibullata), either sessile or planktonic. Rotifers are an important part of the freshwater zooplankton, being a major foodsource and with many species also contributing to the decomposition of soil organic matter.[3] Most species of the rotifers are cosmopolitan, but there are also some endemic species, like Cephalodella vittata to Lake Baikal.[4] Recent barcoding evidence, however, suggests that some 'cosmopolitan' species, such as Brachionus plicatilis, B. calyciflorus, Lecane bulla, among others, are actually species complexes.[5][6] In some recent treatments, rotifers are placed with acanthocephalans in a larger clade called Syndermata.
In June 2021, biologists reported the restoration of bdelloid rotifers after being frozen for 24,000 years in the Siberian permafrost.[7][8] Early purported fossils of rotifers have been suggested in Devonian[9] and Permian[10] fossil beds.
john harris rotifer.