General Characteristics Physical Characteristics

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Biology 111 Mr. Connors
Phylum Nematoda
Ashlyn Foley Matt Hanson, Carine Nzirorera Vince
OConnell Leah Secord Stephanie Totten
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PseudocoelomatesPhylum Nematoda

• Originated from south American Andes
• The name Nematoda comes from the Greek word Nema
  meaning thread, and Eidos meaning form.
• Also known as Roundworms
• The Nematodes were originally named Nematoidea by
  Rudolphi (1808). They were renamed Nematodes by
  Burmeister 1837. then Nematoda (Diesing 1861).

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General Characteristics

• Nematodes are bilaterally symmetrical and
  vermiform.
• They have more than two cell layers, tissues and
  organs.
• Body cavity is a pseudocoel, body fluid under
  high pressure.
• The body of Nematodes is covered in a tough
  cuticle made of epidermal cells or keratinocytes.
  
• Nematodes have a nervous system with a pharyngeal
  ring.
• They do not have circulatory system.
• The body of a nematode has a through gut with a
  subterminal anus.
• Vermiform- long, thin, cylindrical shape of a
  worm.
• Pseudocoel-the body cavity of certain
  invertebrate animals between the body wall and
  the intestine. False body cavity.
• Pharyngeal-of, pertaining to, or situated near
  the pharynx.
• Subterminal -Located or occurring near an end.

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• The bodies of nematodes can range from less than
  1 mm to more than one meter.
• Nematodes are non segmented.
• Nematodes periodically shed their cuticle and
  forms a new, larger one.
• Female nematodes are larger than males.
• Nematodes posess triploblastic protosomes
• There are 25 000 known Nematodes, these include
  parasitic and free-living organisms.
• Nematodes reproduce sexually, which involves
  internal fertilization.
• Nematodes play an important role in decompostion
  and nutrient cycle.
• Triploblastic-having three primary germ layers,
  as the embryos of vertebrates

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Taxonomy

• Phylum Nematoda is divided into two
  classes, Adenophorea and Secernentea.
• Adenophorea are primarily free-living nematode.
  They live in marine, freshwater and terrestrial
  environments. They are considered to be the most
  primitive form of nematodes.

Criconemoides informis
Mononchus (Mononchida - Adenophorea)
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• Secernentea are almost exclusively terrestrial
  nematodes, they are generally parasitic of
  plants, invertebrate and vertebrate animals.

A soybean cyst nematode and its egg
Diplogasterida
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Day to Day Processes
Round worm (Secernentea)
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Day to Day Processes

• Locomotion
• They undulate, meaning they move in a wave-like
  manner. Thick muscle fibers contract with the
  absence of circular muscles.

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Day to Day Processes

• Reproduction
• Nematode's reproduce sexually.
• Males are smaller and have a bent tail
• Nematode's sperm is thought to be the only
  eukaryotic cell without the globular protein G4.

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Day to Day Processes

• What They Eat
• Bacteria
• Fungi
• Protozoans
• Some are filter feeders (straining suspended
  matter and food particles from water)
• Excretion
• Has an anus at its posterior end and a series of
  excretory tubes that end in an excretory pore

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Day to Day Processes

• Digest system

The nematode digestive system is generally
divided into three parts

• Stomodeum- consists of the mouth and lips
• Mesenteron-  Simple tubular intestine
• 3.Proctodeum- Rectum is the short portion of the
  digestive tract at the end of the intestine

Respiration There is no respiratory system but
nematodes use diffusion to breathe.
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Works cited

• www.en.wikipedia.org/wiki/Nematodes
• www.faculty.vassar.edu/mehaffey/academic/animalstr
  ucture/outlines/nematoda
• www.earthlife.com
• www.mcwdn.org/Animals/Roundworms
• Campbell, NeilReece, Jane. Biology,Seventh
  Edition. San Francisco, California, United States
  of America, 2005.
• Bowers, R.Eichorn, D.Silverman, L.de Souza,
  GYoung,R. Biology 11 Toronto, Ontario, Canada,
  2001.