What are rotifers known for?

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. Most species of the rotifers are cosmopolitan, but there are also some endemic species, like Cephalodella vittata to Lake Baikal.

What is the function of the corona Rotifera?

In most species, the head carries a corona (crown) of cilia that draws a vortex of water into the mouth, which the rotifer sifts for food. The food itself is ground by the trophi (jaws), located just behind the mouth in the pharynx (throat).

What is a unique fact about rotifers?

Bdelloid rotifers are one of the strangest of all animals. Uniquely, these small, freshwater invertebrates reproduce entirely asexually and have avoided sex for some 80 million years. At any point of their life cycle, they can be completely dried out and live happily in a dormant state before being rehydrated again.

Are rotifers algae?

Rotifers have no nutritional value themselves, it is the algae they consume that provides this, the rotifers are in effect the transporters of nutrients to the larvae.

Where can rotifers be found?

Although common in freshwater on all continents, some species occur in salt water or brackish water, whereas others live in damp moss or lichens. Most are free-living; some are parasitic. Most live as individuals, but a few species form colonies. Most rotifers are only 0.1 to 0.5 mm (0.004 to 0.02 inch) long.

What is the cuticle of phylum Rotifera?

Body wall of Phylum Rotifera generally lacks a cuticle and thickened into stiff plates or lorica into which the head may retreat. 3. Anterior end with a ciliated organ called corona helps in swimming and feeding. 4. Posterior foot of Phylum Rotifera has two toes; foot with cement glands. 5. Cuticle secreted within epidermis and never moulted. 6.

What is the systematic status of rotifers?

Since their discovery, rotifers have a very uncertain systematic status. Rotifers exhibit superficial similarities with many inverte­brate groups, namely Arthropoda, Annelida and Platyhelminthes A. Affinities with Arthropoda: (i) Body covered by a cuticle. (ii) Superficial metamerism.

What are the characteristics of cilia of rotifer?

Cilia may be arranged uniformly on the corona or may form a ring-like around the corona. Most rotifers are either illoricate or with a fragile lorica. The foot bears two toes. The trophi is virgate type. Scaridium. The conical shaped bodies bear either literal appendages or three to four sen­sory bristles. Foot may be present or absent.

What is a bdelloid rotifer?

FIGURE 3. Typical bdelloid rotifer ( Philodina ). (Modified from several sources.) Most rotifers are free-moving, either swimming as members of the plankton or crawling over plants or within the sediments; however, some sessile species live permanently attached to freshwater plants ( Wallace, 1980 ).