Nematoda (Roundworm)

By: Keenan Faix and Timmy Leehttp://www.ento.csiro.au/science/nematodes/nem_monster.gif

(fake)

Sample Animals

• Soybean Cyst Nematode• http://en.wikipedia.org/wiki/

File:Soybean_cyst_nematode_and_egg_SEM.jpg

http://images.google.com/imgres?imgurl=http://protist.i.hosei.ac.jp/pdb/Images/Multicell/Nematoda/sp_2.jpg&imgrefurl=http://protist.i.hosei.ac.jp/pdb/Images/Multicell/Nematoda/index.html&usg=__h_xLCz2q_2IJmbqA9ayKv6gl4nc=&h=484&w=606&sz=73&hl=en&start=52&um=1&itbs=1&tbnid=rO1sJUizZXHsCM:&tbnh=109&tbnw=136&prev=/images%3Fq%3Dnematoda%26start%3D36%26um%3D1%26hl%3Den%26safe%3Doff%26client%3Dsafari%26sa%3DN%26rls%3Den%26ndsp%3D18%26tbs%3Disch:1

Unidentified Species of a Nemotoda (class Adenophorea)

Body Cavity (Coelom)

• Present• Pseudocoelomate –Body cavity is only

partially lined by tissue derived from mesoderm

Body Symmetry

• Bilateral Symmetry

http://bioweb.uwlax.edu/bio203/s2009/maiers_andr/nematode%205.bmp

Nervous System

• Has a Pharyngeal Nerve Ring–Essentially a ring of nerves starting near the mouth and extending back into the body

Circulatory System

• None - No blood system

http://www.bu.edu/gk12/eric/nematode.jpg

Digestive System

• There is a digestive system with a through gut• Oral cavity opens with a muscular pharynx• Digestive glands found in gut

Excretory System

• Anus• Removes nitrogenous (ammonia) wastes

through the body wall

Locomotion

• Longitudinal Muscles that produce thrashing movement

• Muscular layer surrounds body cavity• Filled with blood-lacking fluids

Skeletal Type

• None

http://www.inra.fr/hyppz/DESSINS/8032041.gif

Sensory Structures

• Lateral Nerves are sensory• Ventral Nerves combine both Lateral and

Dorsal Nerve functions• Contain sensory bristles and papillae to give a

sense of touch• Chemoreception organs near the head

Reproduction

• Sexual• Internal fertilization• Zygotes of most species are resistant to

harmful conditions • Females may deposit over 100,000 eggs in a

day

Gas Exchange

• Diffusion of gasses across the body wall, or cuticle

Other Unique Features

• Found in most aquatic habitat, soil, moist tissue of plants, and in body fluids and tissues

• Body is covered by tough coat called the Cuticle which molts (sheds) after aging

• Many are parasitic

What type of body cavity do nematodes possess?

A) NoneB) CoelomateC) PseudocoelomateD) Acoelomate

Which is not a function of the Cuticle?

A) Diffusion of gasesB) Removal nitrogenous wastesC) MovementD) For Molting

Which one of these is not a Nematode Organ System?

A) DigestiveB) NervousC) CirculatoryD) Excretory

What areas do most Nematodes resided in?

A) SoilB) Aquatic habitatsC) Bodily Fluids and TissuesD) Moist Tissues of PlantsE) All of the aboveF) Volcanoes