Lecture 13: Annelids
Terms in this set (37)
What are some general characteristics of Annelids?
-Marine, freshwater, terrestrial
Why are annelids important to humans?
-food, medicine, fish bait, important in food chain, soil, invasive species
What is metamerism?
segmented arrangement of body parts
Why is metamerism beneficial?
-lessens impact of injury
What is a cuticle?
the outer layer of protective tissue that is shed
What are some general characteristics of Class Polychaetes?
-sand worms, featherduster worms, tube worms
What are parapodia?
lateral appendages extending from body
What are parapodia used?
Parapodia are used for movement and burrowing
How do polychaetes move?
They use longitudinal muscles and parapodia
How do polychaetes feed?
-They are scavengers, herbivores, predators, filter feeders
-direct deposit, selective deposit, filter feeders
How do most polychaetes exchange gas?
What structure potentially helps with polychaetes exchange gas?
What type of circulatory system polychaetes possess?
What are epitoky?
Worms transform into a reproductive morph capable of reproducing
How do Polychaeta reproduce?
-mostly sexual and dioecious
-most fertilized externally
What are some general characteristics of Class Oligochaeta?
-mostly freshwater and terrestrial
Do Oligochaetas have parapodia?
Do Oligochaetas have setae/chaetae?
yes just fewer
What special feature do oligochaetas have?
How do oligochaetes move?
-alternately contract muscles
-use setae as an anchor
How do oligochaetes eat?
-digestive tract with a crop and gizzard
What do the crop and gizzard do?
They aid in the earthworm digestion
What type of circulatory system do Oligochaetes have?
How do oligochaetas do gas exchange/breath?
What are the nephridia on oligochaetes?
used for urine output
How do Oligochaetas reproduce?
What is the seminal vesicle?
What are the seminal receptacles?
This is where worms receive semen from other worms
What is the Clitellum?
special reproductive unit of earthworm that contains eggs and once fertilized secretes it of their body in cocoons
What ecological role do Clitellum play?
They are an invasive species that can weaken roots and churn up the dirt
What are some general characteristics of Class Hirudinea?
-have a clitellum
-anterior and posterior suckers
What do you know about their external strucures?
They have anterior and posterior suckers
How do Class Hirudinea move?
use their suckers as anchors and muscles alternately contract
How do Class HIrudinea feed?
-3 blade like jaws and have a muscular pharynx (crop) to eat
-eat bodily fluids or small invertebrates
What is Hirudo medicinalis used for?
-reduce hematomas or blood clots
Do they produce clitellum?
Only in the spring
Describe the reproduction of Class Hirudinea
-reproduction is sexual