Rotifers belong to which phylum

Hint: Rotifers belong to the phylum rotifera and are also known as wheel animals. It is a small group of aquatic animals which possess a wheel like ciliated organ that are for swimming and feeding purposes. Complete answer- Let us begin with gathering some information about Rotifers. These are mostly found in freshwater environments but some can be seen in salty water too. These can either be free-living like a planktonic species, or can be stationary which lives inside a tube. It contributes to the decomposition of soil organic matter and is also the chief source of food as the maximum part of freshwater is the zooplankton. Rotifers are multicellular organisms that produce new daughter cells through sexual mode of reproduction. They possess both male as well as female reproductive organs and so are dioecious in nature. During the favorable conditions, the female Rotifers produce up to seven eggs simultaneously, without the genetic help of a male rotifer. All these eggs are identical to each other and may hatch in around 12 hours to form new daughter cells. Additional information- Rotifers have an elongated, transparent and cylindrical body. It possesses bilateral symmetry. They are 0.1-1mm in length. It’s body has more than two cell layers with tissues and organs. It’s anterior end contains a crown of cilia called the corona i.e. organized into wheel like ciliary organs from where the name of the group is derived. Note- Rotifers also produce parthenogenetically, in which ...

Key Points • The rotifer body form consists of a head (containing the sensory organs in the form of a bi-lobed brain and small eyespots near the corona), the trunk (containing organs), and the foot (which can hold fast). • The foot of the rotifer secretes a sticky material to help it adhere to surfaces. • Rotifers are filter feeders that generate a current using the corona to pass food into the mouth, which then passes by digestive and salivary glands into the stomach and intestines. • Rotifers exhibit sexual dimorphism; the gender of many species is determined by whether the egg is fertilized (and develops into a female) or unfertilized (and develops into a male). Phylum Rotifera The rotifers are a microscopic (about 100 µm to 30 mm) group of mostly-aquatic organisms that get their name from the corona: a rotating, wheel-like structure that is covered with cilia at their anterior end. Although their taxonomy is currently in flux, one treatment places the rotifers in three classes: Bdelloidea, Monogononta, and Seisonidea. The classification of the group is currently under revision, however, as more phylogenetic evidence becomes available. It is possible that the “spiny headed worms” currently in phylum Acanthocephala will be incorporated into this group in the future. Figure \(\PageIndex\): Rotifers: A bdelloid rotifer is a member of a class of rotifers found in fresh water and moist soil. The rotifer body consists of a head, a truck, and a foot. They eat by filtering food...

Carolus Linnaeus developed a system of classification in the 18th century, which involves giving each organism a scientific name, then placing it in broader and broader categories according to its relationship to other organisms. In order of broad to specific, these seven categories are Kingdom, Phylum, Class, Order, Family, Genus, and Species. Definition of Phylum As you can see, Phylum is one of the broadest of these seven categories. While animals in the same phylum can be very different, they all share similar characteristics. For example, we are in the phylum Chordata. This phylum includes allanimals with a notochord (vertebrates). The rest of the animals are divided up into a very diverse array of invertebrate phyla. Other examples of chordates include marine mammals and fish. Even though we are very different from fish, we share similar characteristics, such as having a spine and being • Acanthocephala- These are parasitic worms that live in the guts of vertebrates and invertebrates. They have a thornyproboscisand may also have spines on their bodies. • Annelida- This phylum contains • Arthropoda- Many familiar types of seafood, such as • Brachiopoda- This phylum includes lamp shells. • Bryozoa-Bryozoansare invertebrates that are also known as moss animals. They are colonial organisms that primarily live in colonies of individuals, and may encrust • Cephalorhyncha- A group of worms that includes spiny-crown worms,loriciferans, horsehair worms, and priapulid worms. •...

Phylum Platyhelminthes The flatworms are acoelomate organisms that include many free-living and parasitic forms. The flatworms possess neither a lophophore nor trochophore larvae, although the larvae of one group of flatworms, the Polycladida (named after its many-branched digestive tract), are considered to be homologous to trochophore larvae. Spiral cleavage is also seen in the polycladids and other basal flatworm groups. The developmental pattern of some of the free-living forms is obscured by a phenomenon called “ blastomere anarchy,” in which a sort of temporary feeding larva forms, followed by a regrouping of cells within the embryo that gives rise to a second-stage embryo. However, both the monophyly of the flatworms and their placement in the Lophotrochozoa has been supported by molecular analyses. The Platyhelminthes consist of two monophyletic lineages: the Catenulida and the Rhabditophora. The Catenulida, or “chain worms,” is a small clade of just over 100 species. These worms typically reproduce asexually by budding. However, the offspring do not fully detach from the parents and the formation resembles a chain in appearance. All of the flatworms discussed here are part of the Rhabditophora (“rhabdite bearers”). Rhabdites are rodlike structures discharged in the mucus produced by some free-living flatworms; Eucoelmate protostomes are schizocoels, in which mesoderm-producing cells typically migrate into the blastocoel during gastrulation likely serve in both def...

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Introduction to the Rotifera Introduction to the Rotifera Rotifers : the "wheel animalcules" Rotifers are microscopic aquatic Because of their very small size and mostly soft bodies, rotifers are not commonly favored for fossilization. Their only hard parts, their jaws, might be preserved in the fossil record, but their tiny size makes detection a serious challenge (Örstan, 1999). However, fossils of the species Habrotrocha angusticollis have been found in 6000 year old Pleistocene peat deposits of Ontario, Canada (Warner et al., 1988). The oldest reported fossil rotifers have been found in Dominican amber dating to the Rotifers : The rotifers are microscopic animals, and under high magnification will look something like the picture at upper left, for most perople using a light microscope. Those with more sophisticated microscopes and lighting techniques can give rotifers such as Philodina, grazing at lower left, a beautiful glow. At right, Collotheca is another monogonont rotifer, shown here bearing an egg on its stalk end. Notice the extemely long coronal cilia this rotifer uses to catch food. (Click on any of the pictures above for a larger image). Rotifers are multicellular animals with body cavities that are partially lined by mesoderm. These organisms have specialized organ systems and a complete digestive tract that includes both a mouth and anus. Since these characteristics are all uniquely animal characteristics, rotifers are recognized as animals, even though the...

By Kenneth Wingerter Progressive aquarists have every good reason to familiarize themselves with the biology of the Rotifaria. Firstly, these diverse and surprisingly complex creatures are quite interesting in their own right; however inconsequential their activities may appear to be, rotifers often exert significant influences on the ecosystems they populate. Further, advancements in the mass culture of certain rotifer species have played a considerable role in the rapid expansion of the mariculture industry over the last quarter century. Cultured rotifers offer an equal measure of promise for use as a feed for nonphotosynthetic corals and other filter feeding organisms. Additional species of rotifer are now being considered for use as live feed for increasingly specialized applications. Hence, an inclusive understanding of these unusual animals is of potentially great value; in the least, familiarity with the group’s natural history and culture procedure can give aquarists–from hobbyists to professional hatchery technicians–the requisite knowledge to produce and utilize them effectively. This piece discusses the classification, etymology, and morphology of the Rotatoria. A following piece will discuss rotifer ecology, development and reproduction. A final piece will discuss rotifer culture. In all pieces, an emphasis is placed on certain members of the genus Brachionus, owing to their present importance in the aquarium industry. There is a considerable variety of body fo...

Rotifera is a Phylum of primary freshwater Metazoa containing two major groups: the heterogonic Monogononta and the exclusively parthenogenetic Bdelloidea. Monogononta contains 1,570 species-level taxa, of which a majority (1,488) are free-living fresh or inland water taxa. Bdelloidea contains 461 “species,” only one of which is marine, but with many limnoterrestrial representatives or animals of unknown ecology. Actual numbers may be much higher, considering the occurrence of cryptic speciation in Monogononta and the unsatisfactory nature of taxonomic knowledge. Rotifers, mostly monogononts, occur in all types of water bodies, worldwide. They are particularly diverse in the littoral zone of stagnant waterbodies with soft, slightly acidic water and under oligo- to mesotrophic conditions. The rotifer record is highest in the Northern hemisphere, which may be due to the concentration of studies in those regions. Diversity is highest in the (sub)tropics; hotspots are northeast North America, tropical South America, Southeast Asia, Australia, and Lake Baikal, endemicity is low in Africa (including Madagascar), Europe, the Indian subcontinent, and Antarctica. Although the lack of fossil evidence and of molecular phylogenetic studies are major hindrances, contrasting hypotheses on the origin and evolutionary history of Brachionus, Macrochaetus, and Trichocerca are presented. • Beres, K. A., R. L. Wallace & H. H. Segers, 2005. Rotifers and Hubbell’s unified neutral theory of Biod...