Platyhelminthes--continued

Parasitism and the loss of the digestive tract

1. Complete gut (mouth, pharynx, intestine and anus)
2. Muscular pharynx for pumping food into intestine

No gut due to parasitic nature.  Cuticle prevents host from digestion worm.   Can absorb nutrients through body wall

1. Use corona of cilia to produce current that flows towards the mouth
2. Use mastax to masticate food particles

Complete gut (mouth, pharynx, stomach, intestine and anus)

1. Gut has typhlosole--increases surface area of intestinal tract
2. Gut also has glands that produce a buffer material

1. Some function very much like earthworms
2. Some are carnivorous--have pinchers at base of evertible proboscis
3. Some are filter feeders

Sabellid worms and tentacular crown

Chaetopterus and muscous bag

Amphitrite and tentacles