=
1.
™ Platyhelminthes
™ aka
2.
™ Nematoda
™ aka
Coelom =
=
Kingdom: Animalia
Phylum: Platyhelminthes
Class :
Class :
Class :
Phylum Nemertea –
Phylum GnathostomulidaPLATYHELMINTHES = “platy” = “helminth” =
1. Body structure
size range
------►
(Cestoda)
♦ Acoelomate =
♦ No cavity
♦ Space between body wall and digestive tract is filled with
(
)
♦ Shape –
2. Level of Organization –
3. Symmetry – (has
&
)
4. Habitat – aquatic (
)
5. Feeding - depends on class
¾ Turbellaria – planarians
• Mostly
•
digestive tract – one opening (
• Mouth
• Protrusible
• Gastrovascular cavity (GVC)
•
•
digest food
)
¾ Trematoda –
•
•
E.g.
¾ Cestoda – tapeworms
•
•
•
6. Respiration via
Endo-parasites
NO need for dig. tract –
(only a few cell layers thick)
7. Internal transport – via
8. Excretion – via diffusion
EXCEPTION: planarians have
move waste to
9. Response – (Nervous system)
• Primitive
– anterior ganglia
(ganglion =
• Ladder-like
• Sense organs:
1. Ocelli –
2. Auricles 3. Statocysts –
4. Rheoreceptors –
( w/
that help
, then out of the body
)
10. Locomotion –
o Planaria
to GLIDE
o Trematoda, Cestoda –
11. Reproduction
♦ Asexual –
♦ Sexual –
12. Ecological Roles
(Planaria only)
(hermaphrodites)
(swap sperm)