Nematoda

1. Nematoda
(nematodes -Heterodera glycines)
By: Sarah Larsen
5/19/09
Period 4

2. Classification
•Usually classified into 5 main groups:
•Bacterivores- bacteria eating nematodes
•Fungivores- fungus eating nematodes
•Predators- eat other nematodes of the same
size.
•Omnivores- eat more than one food material
•Unknown- food source has not been
determined yet.

3. , ,
Bodyform symmetry andskeletal
systems

• Tripoblastic: Has 3 germ layers… Ectoderm(cuticle),
Mesoderm and Endoderm.
•Psuedocoelomate Animal: has a fully functional body cavity.
•Bilateral Symmetry: when one side of the body mirrors the
other.
•Nematodes
do not have a
segmented
body.

4. Reproduction
• Generally sexual, sometimes asexual,
involves internal fertilization.
•Most species, sexes are separate, the male is
smaller than the female.
•Female nematodes can deploying over
100,000 eggs in a day.

5. FeedingandDigestiveSystem
•Food is transported in the psuedocoloem by
interior and exterior pressures.
•Three parts: stomodeum, intestine, proctodeum.
•The stomodeum = the “mouth and lips”, buccal
cavity, and the pharynx (esophagus).
•Buccal cavity = tube that can contain small
‘teeth’ , food is sucked through the mouth into the
buccal cavity.

6. CirculatorySystem
•Nematodes have a separate circulatory
system made up of muscular tubes.
•Circulatory system: circulating fluid within
the pseudocoelom.

7. RespiratorySystem
•Respiratory system: respiration by
diffusion.

8. Environment
•Nematodes are mostly found naturally in
soil.
•Parasitic nematodes will live in a host
such as an insect or plant.

9. HumanInteractions
•Some parasitic nematodes are the cause of
many dangerous and even life-threatening
diseases.
•Such as Trichinosis, Hookworm Infection, and
Intestinal Roundworm Infection.
• Some are very helpful to people ‘cause they eat
pests that can kill plants.

10. UniqueFeatures
• 25,000 species have been identified, scientists
estimate that that is only 5% of what could be
out there.
•Over 50 species live in humans alone.
•Species range vastly in size, from under a
millimeter to over a meter.

11. Species
Hookworms
(Ancylostoma duodenale)
Roundworms
(Parascaris equorum)
Pinworms
(Strongyloides stercoralis)

12. Bibliography
•www.cusmibio.unimi.it/.../nematodes/index3.htm
•http://www.eol.org/pages/2715
•http://entnemdept.ufl.edu/creatures/nematode/soil_nematode.htm
•Silverstein,Robert. Invertebrates. New York, N.Y.:Twenty-
First Century Books, 1996.
•http://ucdnema.ucdavis.edu/imagemap/nemmap/ENT156HTML/vertlife
•http://nematode.unl.edu/digestive_system.html