Download Phylum Platyhelminthes

Phylum Platyhelminthes
FLATWORMS: planaria,
flukes, tapeworms
tapeworm
Planarian
fluke
• Habitat
–Marine, freshwater, moist land
• Importance
–Cause disease, parasitic in plants
and animals
Method of obtaining food/digestive
system
• Extends pharynx and sucks up
food into gastro vascular cavity or
absorbs nutrients from host
Asexual Reproduction
• regeneration (some)
• fission
Sexual Reproduction
• Most are
hermaphrodites
• Internal sperm
exchange
• Life cycle with
many hosts
Parasitic Blood
fluke
Symmetry
• Bilateral
Internal Body Cavity
• Coelom
–Fluid filled space found between the
body wall and the digestive tract
Internal body cavities/ tissue layers
• Ectoderm- outer
• Acoelomates- no
layer of skin;
body cavity
• Pseudocoelomates nervous system;
sense organs
- (false body cavity)
body cavity located • Endoderm-lining of
digestive tract;
between the
digestive organs; etc
endoderm and
• Mesoderm-most of
mesoderm
the skeleton,
• Coelomates-true
muscles,
coelom…located
reproductive organs
entirely within the
mesoderm
Nervous System
•
•
•
•
Ganglia
Eyespots
Ability to learn
Sensory organs
Circulatory/Respiratory
• diffusion
Fresh water
planarian
Anything else
• Tapeworm can grow 10 m long
• Flukes need snails and humans
to reproduce.
Phylum Nematoda
Roundworms
Habitat
• Soil, marine, animals, freshwater
Hook worm
ascaris
Importance
• Parasitic (some) in
plants and animals
Method of obtaining
food/digestive
system
• Parasitic-absorbs
nutrients
• Predators-catches
food in mouth
Digestive
system
Asexual reproduction
• none
Sexual Reproduction
• Internal fertilization
• Male deposits sperm
• Parasites has 2-3 hosts
Symmetry
• Bilateral
Nervous System
• Free living
• Sense organs
Circulatory/Respiratory
• Diffusion
Anything Else
• Moves with muscles and cilia