1. ZOO 115 Invertebrate Zoology Nematoda

2. hooge.developmentalbiology.com/meiofauna/media Phylum Nematoda • Common name: round worms • >20,000 species. • Mostly widespread and abundant of all metazoans • 90,000 worms in a decomposing apple. • Marine and freshwater benthos, soil, parasites on plants and animals

3. /creatures.ifas.ufl.edu/nematode Nerve cords Digestive tract Ovaries Excretory canal Phylum Nematoda - Anatomy • Most freeliving <2.5 mm in length. Some parasites > 50 cm in length. • Body is cylindrical with a pseudocoel • Complex cuticle • Must molt (Ecdysis) • Anterior end is radially symmetrical but the rest of the body has bilateral symmetry

4. Sensilla /creatures.ifas.ufl.edu/nematode Sensilla • Ring-like brain • Sensilla • Chemosensory • Males also have them near the anus /creatures.ifas.ufl.edu/nematode Brain • Dorsal, ventral and lateral nerve cords www.unice.fr/LEML/coursJDV/images/biologie/ www.unice.fr/LEML/coursJDV/images/biologie/ Phylum Nematoda - Head RegionNervous system

5. /creatures.ifas.ufl.edu/nematode Stylet - like a Hypodermic needle • Muscular pharynx 3 to 6 lips Pharynx /creatures.ifas.ufl.edu/nematode Buccal Cavity Phylum Nematoda - Head Region • 3-6 lips at the mouth • Buccal Cavity varies depending on prey • Bacteria - no teeth or stylet • Plant root - stylet • Carnivore - small teeth and sometimes stylet • Intestine - large hook-like teeth

6. /creatures.ifas.ufl.edu/nematode /creatures.ifas.ufl.edu/nematode /creatures.ifas.ufl.edu/nematode • Foregut (buccal cavity and pharynx shown earlier) • Midgut -Intestine Cuticle Anus • Hindgut - Rectum Rectum Intestine Phylum Nematoda - Digestive tract

7. www.ustboniface.mb.ca/cusb/abernier/Animaux/Pseudocoelom Longitudinal Muscles Nerve cords Digestive tract Ovaries Excretory canal Phylum Nematoda – Excretion • Excretory glands and canals thought to be involved in: • Osmoregulation • Ionic regulation • Excretion of waste metabolites • Ammonia secreted through body wall

8. www.ustboniface.mb.ca/cusb/abernier/Animaux/Pseudocoelom Longitudinal Muscles Nerve cords Digestive tract Ovaries Excretory canal Phylum Nematoda – Musculature • Longitudinal muscles only!

9. Spicule Testis www.apsnet.org/education/LessonsPlantPath/PineWilt/images/ Rectum - Cloaca creatures.ifas.ufl.edu/nematode/ Phylum Nematoda - Reproduction • Separate sexes - usually • Males have hook-like posterior • Testis • Male Rectum - Cloaca • Reproduction • Digestive waste • Spicule for sperm transfer • Retractable

10. creatures.ifas.ufl.edu/nematode/ Ovary Seminal recepticle Eggs Vulva creatures.ifas.ufl.edu/nematode/ Phylum Nematoda - Reproduction • Females • Ovaries • Eggs • Vulva • Seminal Receptacle

11. Baylisacaris procyonis Racoon parasite www.extension.umn.edu/distribution/cropsystems/images Human Parasite Plant parasite Ascaris lumbricoides Phylum Nematoda - Parasites: Roundworm Life Cycles

12. www.biosci.ohio-state.edu/~parasite/lifecycles Phylum Nematoda - Parasites: Hookworm

13. Phylum Nematoda - Parasites: Trichinella

14. www.cvm.okstate.edu/~users/jcfox/htdocs/DISK1/IMAGES/ Phylum Nematoda - Parasites: Filariasis