Characteristics Flashcards
Type of symmetry?
Bilateral symmetry
How many germ layers?
3
Triploblastic
Type of body plan?
Tube-within-a-tube body plan
How is the body segmented?
By the rings that encircle the body.
Another term for segmentation?
Metamerism
What is each segment called?
Somite
Type of body cavity?
True coelom
Structure of body cavity?
The well-developed & fluid filled coelom is divided internally by partitions called **septa **& serves as a hydrostatic skeleton.
Function of hydrostatic skeleton?
Provides structure against which mucles can pull & allows improved movement of individual body segments during locomotion.
Covering of body?
A thin cuticle covers the body & setae are usually present (used for locomotion).
What are Setae?
Bristles that anchor the worm & help it move.
Type of circulatory system?
Closed system
Type of reproductive system?
Hermaphroditic
Sexual reproduction
Type of habitat?
- Most species are marine
- Some freshwater
- Some terrestrial
Give some examples
- Clamworm or sandworm (Nereis)
- Earthworm
- Leeches (Hirudo)
What are Leeches?
- Blood-sucking parasites that inhabit freshwaters.
- They have neither setae not appendages.
