2. Types of Marine Worms
Phylum Platyhelminthes – the flatworms
Phylum Nemertea – the ribbonworms
Phylum Nematoda – the roundworms
Phylum Chaetagnatha – the arrow worms
Phylum Pogonophora – the deep sea tubeworms
Phylum Annelida – the segmented worms
7. Phylum Platyhelminthes – the flatworms
-Ex:
Tapeworms, Planaria, Parasit
ic Fluke
-Some parasites, some free-
living scavengers or
predators
-Some cause “Swimmers’
Itch”
9. Phylum Platyhelminthes cont.
• Mouth/Anus
in same spot
• Simplest
animal to
have a CNS
• Light sensitive
eyespots
• 3 cell layers
10. Phylum Annelida – the segmented worms
• Ex:
earthworms, leeches, pol
ychaetes (bristle worms)
• Bodies divided into ring-
like sections
• More advanced of the
worms
• Bilaterally symmetrical
11. Phylum Annelida cont.
• Coelom – fluid
filled body space
• Between
digestive tube
and body wall –
helps animal
move, acts like a
skeleton
12. Phylum Annelida cont.
• Other advances include:
– Body systems (not present in more primitive
worms), i.e. digestive, nervous, circulatory (with
blood, hemoglobin)