Phylum Annelida Essay

Phylum Annelida

Annelids are members of the Superphylum Lophotrochozoa. The division of the Phylum is in three classes Hirudineans (leeches), Oligochaetes (earthworms) and Hirudinean (Polychaetes and leeches). They inhibit marine aquatic with Parapodia, like nereis Meglitsch P, 1972()

They are worm like animals that have muscular body walls that elongate. They are also circular in cross section. The major difference between Phylum Annelida and other worm like creatures is that, they have segmented bodies (also known as metameric). Each segment has its own particular function. Phylum Annelida include different types of earthworms, leeches and marine polychaetes. There are those that live in fresh water, marine also terrestrial. Some of them live as parasites. Annelids are skilled in swimming, creeping and burrowing Badea, Gagyi-Palffy, Stoian, & Stan, 2010

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Meglitsch P (1972)

, said that Annelids are connected to Molluscs and seem to have arisen from flatworms.Given the characteristics that the Annelida display, they may be the predecessors to arthropods. Meglitsch's arguments are made from the fact that they both have segmentation. Among Phylum Annelida, those consider most primitives and polychaetes though to-date they have been relegated degenerate Badea et al., 2010

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Characteristics of Phylum Annelida

Characteristics that Phylum Annelida possesses which are distinctive from the other worm like creatures are given in this section. Phylum Annelida have no backbones they have cylindrical segmented bodies (metameric). Their digestion is extracellular, meaning they have a complete mouth to anus digestive system with muscular walls such that body movement does not interfere with digestive tract movements Badea et al., 2010

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. They are vascular - meaning they have a well developed circulatory system - with vessels for pumping and distributing substances throughout the body. They.....