Nematoda


 * By August Kim**


 * Phylum:** Nematoda


 * Subkingdom:** Parazoa


 * Class:** Adenophorea, Secernentea


 * Sub-classes:** Enoplia, Chromadoria, Rhabditia, Spiruria, Diplogasteria


 * Body Plan:** The body is bilaterally symmetrical and vermiform (worm-like). The body is made up of more than two cell layers, tissues, and organs. The body cavity is also a pseudocoel ("false cavity") and it has a through gut with a subterminal anus. The epidermis of the nematoda is covered in a complex cuticle. It has a nervous system with pharyngeal nerve ring and has no circulatory system. The way that nematodas reproduce is through normal sexual contact and gonochoristic. It will feed on just about everything and lives just about everywhere. Essentially, the Nematoda is a long hollow tube with another tube inside of it.


 * Germ Layers:** The outer cuticle is made up of 3 germ layers. These 3 different layers, starting from the outside, are called the cortex, the matrix layer, and the fibre layer.


 * Symmetry:** The Nematoda is bilaterally symmetrical, meaning it could dividing into matching halves by drawing a line down the middle.


 * Coelomate:** Nematodas have a pseudocoelem, which is filled with paired sets of reproductive organs[[image:http://upload.wikimedia.org/wikipedia/commons/thumb/2/28/Soybean_cyst_nematode_and_egg_SEM.jpg/220px-Soybean_cyst_nematode_and_egg_SEM.jpg width="161" height="133" align="right"]]


 * Habitat:** Nematodas have a wide variety of habitats from the bottom of the deepest ocean to the tops of the highest mountains. They basically live in any kind of habitat. Nematodas are also found as parasites which cause many diseases to man and other animals as well as plants.

to flail side to side that pushes them forward.
 * Movement:** They can "swim" but it is not an accurate description of how it actually moves. Nematodas only have longitudinal muscles that allow them
 * Skeletal System:** They are similar to earthworms in that they have round cross sections. They are different from worms because they can maintain their body fluids under great pressure. This allows Nematodas


 * Evolutionary Advancement:** Still primitive but have evolved more towards being a parasite than just a organism living on its own


 * Special Adaptations:** They can maintain body fluids under incredibly high pressures. On average the internal pressure equals 1.49 PSI


 * Feeding Patterns:** Most Nematodas are carnivores, meaning they eat animals and organisms even smaller than they are. Sometimes they even eat other Nematodas. Some Nematodas feed on plants or vegetation.
 * Respiration:** Respiration occurs through the Nematoda cuticle permeable to both water and gases


 * Circulation:** Nematodas have no circulatory system


 * Excretory:** The waste of Nematodas are secreted via two simple ducts or tubules
 * Nervous:** Nematodas have well developed nervous system. It is made up of a circum-pharyngeal nerve ring made up from 4 nerve ganglia from which 6 longitudinal nerve extend down through the body to the various parts of the gut and the reproductive organs. There are also 6 shorter nerves which extend forward from the circum-pharyngeal ganglia towards the mouth.


 * Reproduction:** Most of the Nematodas body cavity is filled with paired sets of reproductive organs, either ovaries. Male and female Nematodas have sexual intercourse with the help of the male's 2 stiff horny spicules. The females can lay her eggs at a rate of up to 200,000 eggs per day and have over 27 million eggs total.[[image:sharonapbio-taxonomy/nematode.jpg]]

[] [] [] http://www.ucmp.berkeley.edu/phyla/ecdysozoa/nematode.jpg [] http://entnemdept.ufl.edu/creatures/nematode/soil_nematode02.gif