Transcript 8 Worm Worms and Worms

WORMS, WORMS, AND
MORE WORMS
June 2, 2016
Flatworms
Classification
Kingdom: Animalia
 Phylum: Platyhelminthes

Basic Characteristics
1.
2.
3.
4.
Flatworms are the simplest of the worm
groups.
There are about 20,000 species in this group.
They are found many places and can be free
living or parasitic.
Show cephalization
Basic Characteristics (cont.)
5.
6.
One of the best-known flatworms is the tapeworm.
The tapeworm can get into a person's digestive
tract and grow to enormous lengths.
Flatworms are found in marine and fresh water.
FYI:
Longest
Tapeworm to be
pulled out of a
human was 37
feet long
Flatworm Systems

Body Cavity



Acoelomate
Combo digestive & excretory
 Gastrovascular cavity
 Takes food in and gets rid of
wastes through same opening

Muscular-Skeletal
No skeleton
 Tiny bristles called cilia that
help it move
 2 layers of muscles under
its skin
 3 cell layers (endoderm,
mesoderm, and ectoderm)
Digestive


Nervous
Simple nervous system with 2
nerve cords running down
either side
 2 simple brains called
ganglia, which are simple
bundles of nerves
 2eyespots that help it sense
light

Flatworm Systems (cont.)

Circulation


Respiration


Fluid in body acts like a
primitive circulatory system
Takes in oxygen, but has no
formal system
Reproduction
Sexually: simultaneous
fertilization
 Asexually: Reproduces by
splitting in two. When it
splits up, it immediately
forms a new flatworm.

Flatworm Systems (cont.)

Excretion
Gets rid of wastes through
the same opening it takes
in food
 Flame cells function like a
kidney, removing waste
materials


Symmetry


Bilateral symmetry
Appearance

Can be microscopic or
many feet long and is
generally very thin
Roundworms
Classification
Kingdom: Animalia
 Phylum: Nematoda

Basic Characteristics
1.
2.
3.
4.
5.
More advanced than flatworms
but less advanced than
earthworms.
They have thin round bodies,
without pieces or segments.
Roundworms live in salt water,
fresh water, & the soil.
Many of them are harmful to man
as they are parasites.
Examples: hookworm, pinworm, &
trichinella are part of this group.
Roundworm Systems

Body Cavity


Muscular-Skeletal


Pseudocoelomate
No skeleton
Digestive
Definite digestive system
that runs the length of their
bodies
 Has mouth, pharynx,
intestine, & anus
 Many are parasites & live
off other animals & plants


Nervous

2 nerve cords that transmit
impulses in the roundworm
Roundworm Systems (cont.)

Circulation


Respiration


Has no heart or formal
blood vessels
Takes in oxygen, but has no
formal system
Reproduction
Sexually
 Female: has ovary, holds
eggs in an oviduct, & then
into uterus, where fertilized
 Male: has sperm cells are
made in the testis & stored in
vas deferens

Roundworm Systems (cont.)

Excretion
 Has
an anus at its rear
end & a series of
excretory tubes that end
in an excretory pore

Symmetry
 Bilateral

symmetry
Appearance
 Thin,
round, smooth and
can be up to four feet in
length
Segmented Worms
Classification
Kingdom: Animalia
 Phylum: Annelida

Basic Characteristics
1.
2.
3.
4.
5.
Earthworms are the most highly
developed worms.
They are divided into segments or
parts.
They are found in salt and fresh
water as well as in the soil.
Earthworms are helpful to man as
bait for fishing and more importantly,
because they loosen the soil for roots
to grow.
There are 2700 species of
earthworms.
Segmented Worm Systems

Body Cavity
 Coelomate

Muscular-Skeletal
 No
skeleton
 Bristles on each segment
called setae that help it
move
 2 sets of muscles; 1 that
makes it long & thin and
1 that makes it shorter &
fatter
Segmented Worm Systems

Digestive
 Eats
dirt, digesting the plant and animal matter in the dirt
and then eliminates the rest
 Esophagus
for the food to go down
 Crop to store the food in
 Gizzard that grinds the food down
 Intestines for the food to pass through and take out nutrients
 Anus for the food to come out
Segmented Worm Systems (cont.)

Nervous
 Simple
brain & ventral
nerve cord

Circulation
 Blood
& blood vessels with
multiple (5) hearts

Respiration
 No
formal system
 Takes in O2 directly
through skin & gives off
CO2
 Skin is always moist
Segmented Worm Systems (cont.)

Reproduction
Has both sperm &
eggs within its body
 Eggs must be fertilized by
the sperm of another worm

 Sexual:

Excretion
 Waste
helps to fertilize soil
 Gets rid of wastes through
tubes called nephridia that
lead to pores that allow the
wastes out
Symmetry
 Bilateral

Appearance
 Earth-tone
colors
 Can be up to 8 ft long