Annalids Flashcards
What are annelids
Segmented worms
What is metamerism
Condition of being constructed in a linear pattern of repeating parts
What is the structure of each segment in annelids
Dorsal blood vessel
Ventral nerve cord
Gut through the centre
Ceolom is present
How do annelids move
They either crawl/swim rapidly by wriggling side to side
Constriction of circular muscles elongating segments causing them to be pushed forward (like in earthworms)
What are chaetae
Bristles made of chitin
They help anchor the annelid within its burrow
What are the key characteristics of the annelid circulatory system
Closed system
Muscular blood vessels
Used haemoglobin
Body walls act as a general surface for gas exchange, but only in moist environments
What are the orders within the annelid group
Polychaeta (have paired appendages e.g. bobbit worms)
Clitellata (earthworms and leeches)
Why are annelids very important to their ecosystems
They break down organic matter (bioturbation)
Increases oxygen penetration into the sea floor
Important food source
