Class Turbellaria (Phylum Platyhelminthes)

Question 1

Where are they found?

Answer 1

fresh water or marine (salt-water)

Question 2

Form of locomotion

Answer 2

cilia (on ventral side) for creeping along a substrate

Question 3

Muscle layers:

1. circular muscle layer

Answer 3

reproduction via fragmentation

Question 4

Muscle Layer

2. longitudinal muscle layer

Answer 4

swimming/locomotion

Question 5

Muscle Layer

3. dorsoventral muscle layer

Answer 5

internal movement

Question 6

Feeding role

Answer 6

predators, herbivores, & detritivores (eats stuff like skin that falls off)

Question 7

Sensory/nervous

Answer 7

• ocelli (eye spot) – photosensitive but not capable of making images
• auricles: chemosensitive (use to smell)
• mechanoreceptors: can feel

Question 8

Reproduction/regeneration

Asexual

Answer 8

• fragmentation
• if you cut it up, will grow back organs

Question 9

Reproduction/ Regeneration

Sexual

Answer 9

• monoecious
  
  • sometimes they have bidirectional sperm exchange → both become pregnant
  • penis fencing – whoever is poked first is female
• If female, you’re stuck. If male, have advantage b/c can go fence w/ others.