Subclass Oligochaeta (Class Clitellata/Phylum Annelida)

Question 1

What does “oligochaeta” mean?

Answer 1

“few hairs/bristles”

Question 2

How do they perform locomotion?

Answer 2

• alternating contraction of circular & longitudinal muscles
• circular muscle → push forward → longitudinal → setae → anchored and repeat process

Question 3

Digestive Tract

Answer 3

• food → mouth → pharynx → esophagus → crop → gizzard (muscular structure) where mechanical breakdown so enzymes can work on it → intestine (typhlosole) increases SA & secretes digestive enzymes → anus

Question 4

What do they do for reproduction?

Answer 4

• sexual
• monoecious → bidirectional sperm exchange
• finds guaranteed mate
• gravid → secretes larva in cocoon through slime tube (keeps it wet)