Transcript Slide 1

Marine Worms
(Flatworms, Segmented Worms,
Roundworms)
General Stuff About Worms…
• Worms are found pretty much
everywhere in the ocean.
• Most worms tend to live near the
seafloor.
• Some of the worms we will be
discussing are parasitic.
• There are a number of different
groups , or phylums, each having it’s
own distinctive characteristics.
Worms, Worms, Worms!
Phylum- Platyhelminthes
(aka: Flatworms)
 Have flat bodies.
 Found in both fresh and salt water.
 Can range in size from microscopic to
nearly 20 meters (60 feet!)
 Have bilateral symmetry.
 Move by contracting muscles and beating
of cilia.
 Have a very simple nervous system.
 Have a very simple digestive system.
 Reproduce asexually (regeneration) or
sexually (hermaphrodite).
Flatworms
Tapeworms
 These worms are parasites.
 They live in or on the body of a host
organism.
 They do not need digestive systems
because the absorb nutrients directly
from the host into their own bodies.
 Some examples are: Blood fluke,
Liver Fluke, Trematode.
Tapeworms
Roundworms
• These are the most common type of worm.
• There are about 10,000 different species of
roundworm!
• They generally live at the bottoms of
oceans, and burrow in sand and mud.
• They whip their bodies back and forth to
move around.
• Some can swim.
• They belong to the phylum Nematoda.
• There are two sexes, but some are still
hermaphroditic.
Roundworms
Segmented Worms
• Typically found in moist soil or sand.
• Belong to the Phylum “Annelida”.
• There are more than 10,000 species of
segmented worms.
• They have a well developed digestive,
circulatory, and nervous system.
• They breathe through their skin and have
moist bodies.
• Oxygen and Carbon Dioxide diffuse through
the skin.
Segmented Worms