Nematodes in Spongebob
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Nematodes have THREE germ layers
1. Cuticle layer: Strong, flexible (Outer)
2. Epidermis layer: mass of cellular material
and nuclei without separate membranes
(Middle)
3. Muscle Layer: Makes nematodes only able to
move side to side (Inner)
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Nematodes are BILATERALLY symmetrical
Roundworm
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Nematodes ARE NOT coelomate.
Nematodes instead are PSEUDOCELOMATE
Pseudocelomate: Body cavity for the organs
lined with mesoderm
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COMPLETE digestive tract:
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Has both a mouth and an anus
Because of this simple digestive system, nematodes
can CONSTANTLY eat
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http://www.youtube.com/watch?v=0N0epPU
UZ60
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Nematodes have a RING OF NERVOUS
TISSUE around the pharynx that leads to the
dorsal and ventral nerve. These run the length
of the ENTIRE BODY
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Nematodes are a type of round worm that are
NOT SEGMENTED.
No separation occurs.
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Nematodes range from microscope to 5cm
long.
They do not have an internal skeleton, they
instead have a cuticle that covers their body
and keeps their shape (hyrdostatic).
They have no appendages.
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Nematodes do not have a defined circulatory
system.
They instead deposit all their fluids into the
pseudocelomate.
They also do not have a respiratory system –
they instead have nutrients and waste together
in the body cavity and excrete it.
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Nematodes have both the sexes in their species.
Males are generally smaller than females.
They reproduce in a similar fashion to humans.
However, in free-living worms, the eggs hatch
into larvae.
In parasitic roundworms, the lifecycle is much
more complicated.
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Nematodes have adapted to almost every
environment from salt water to inside a
human.
They outnumber other animals in numbers and
in diversity – possible 500,000 variations.