Class Bdelloidea It is the second-largest group, and contains about 350 species of rotifers. Body possesses a through gut with an anus. Body cavity is a pseudocoelom. Most rotifers are about 0.5mm in length or less, and their bodies have a total of around a thousand cells. Phylum Rotifera is comprised of two classes, Eurotatoria (which includes orders Monogononta and Bdelloidea) and Seisonidea, with over 2,200 currently known species.They are most commonly found in freshwater, although some species live in brackish or marine habitats, in soil, or on mosses. Body has more than two cell layers, tissues and organs. Rotifers are small (50-1000 µm) zooplankton that occur in freshwater, brackish, and marine environments. You can easily find … The trunk is elongated and often enlarged. Has a nervous system […] Diversity. Most rotifers are solitary, free swimming or crawling animals, but there are sessile as well as a few colonial species which are in fact aggregation of solitary individuals. There is a slender terminal posterior tail or foot. Class Seisonidea You can also see the color of the food they just ate! Rotifers aren't easily seen such as pods are and that is the first advantage to our reef tanks, size. Rotifers have real organs, including a brain, stomach and intestines. Rotifers are usually transparent, so you can see their organs. Class Monogononta It is the largest group of rotifers, containing about 1,500 species. The anterior end is broad or narrowed and is usually equipped with a ciliary apparatus. Rotifers are microscopic animals found in aquatic environments all around the world. They are divided into the following three classes. As the name suggests, all animals in this phylum are called rotifers. 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 (Figure 1).Although their taxonomy is currently in flux, one treatment places the rotifers in three classes: Bdelloidea, Monogononta, and Seisonidea. Rotifers feed on microalgae and are consumed by a wide variety of fish, shellfish, corals, and other organisms. There is a … Characteristics of Rotifera: Bilaterally symmetrical. We can think of them as mighty mini lunch bags loaded full of nutrients. Rotifers are small, mostly freshwater animals, and are amongst the smallest members of the Metazoa -- that group of multicellular animals which includes humans, and whose bodies are organized into systems of organs. Asplanchna) or spherical (Trochosphaera), while some are wide and The rotifers make up a phylum of microscopic, and near-microscopic pseudocoelomate animals. Their size makes it a lot easier for our beautiful corals [even fish larvae for fish breeders] to digest. Rotifers are 0.04 to 2 mm long with most below 0.5 mm. Body covered in an external layer of chitin called a lorica. Rotifers are found in fresh and marine water as well as in moist terrestrial habitat among mosses and lichens. Rotifers may be sessile or sedentary and some species are colonial. Some rotifers are sacciform (sac-shaped) (e.g. Phylum: Rotifera. The Phylum Rotifera Etymology- From the Latin Rota a wheel, and Ferre to bear or carry. What Are Rotifers? Fun facts: A vernal pool is a great place to see Rotifers. There are a variety of different shapes of rotifer.