The organisms belonging to phylum Nematoda are roundworms, examples of which are ascaris, trichinella, filaria worms, hookworms and pinworms. Nematodes are part of a group of animals, known as ecdysozoans, that periodically shed their skin as they grow. Although nematodes are frequently found in nature, numerous species live as internal parasites in most vertebrates, including humans.
Phylum Nematoda is a sub-category of Kingdom Animalia, which consists of multicellular heterotrophs that require oxygen for survival. Under this phylum, taxonomists have already classified around 16 to 20 orders. Since the mid-1980s, more than 2,200 genera and 15,000 species have been identified.
The anatomy of nematodes includes a mouth, retracted piercing device, nerve ring, pharynx, intestine, ovary, pseudocoelom, cuticle, reproductive pore, anus and excretory pores. Although these organisms lack a circulatory system, roundworms possess a complete digestive tract. The pseudocoelom contains fluids that aid in the transportation of nutrients. Some nematodes, particularly those species that are abundant in soil, are grouped according to their feeding habits. Herbivores feed on plants, bacterivores on soil bacteria, fungivores on fungi, predators on other nematodes or similarly sized organisms and omnivores on several types of food sources. Members of the order Tylenchida, Rhabditida, Aphelenchida, Mononchida and Dorylaimida are generally considered as herbivores, bacterivores, fungivores, predators and omnivores, respectively.Learn More
Paramecia belong to the phylum Protozoa, which falls into the kingdom Protista. Paramecia are considered free-ranging protozoans that are generally very small in size. There are eight species of paramecium, which vary in appearance but share the characteristics of being single-celled organisms that are covered with tiny delicate hairs called cilia.Full Answer >
All true fish belong to the phylum Chordata. Animals of this phylum possess a hollow backbone, and at various stages of development, all have grooves and slits in the area of the throat behind the mouth and a tail that extends past the anus.Full Answer >
Earthworms belong to phylum annelida. This phylum is part of the animal kingdom and includes marine, freshwater and terrestrial worms in addition to leeches.Full Answer >
Planaria are non-parasitic flatworms that are grouped in the phylum Platyhelminthes. This puts planaria in the same general family as tapeworms and liver flukes. Planaria are distinguished by their lack of a body cavity and circulatory system.Full Answer >