Test2 Flashcards
(192 cards)
What are the three classes of annelids?
Polychaeta: polychaete worms
Oligochaeta: earthworms
Hirundinea: leeches
What is the most abundant class of annelids?
Polychaeta: polychaete worm
What is the second most abundant class of annelids?
Oligochaeta: earthworm
How many species of polychaete worms are there?
Over 10,000
What does the name polychaete mean?
The name polychaete means many bristles (or chaeta)
What features are on the head of a polychaete?
Polychaetes have a well differentiated head that has sense organs including eyes and cirri (short tentacles), jaws (in predatory forms), or a fan for filter feeding.
What do each segment of polychaete have?
Parapodia
What functions do parapodia have?
Crawling, anchoring to the substrate, and serves as gills
What two basic life styles do polychaete have?
Sedentary- borrow into the sediment
Errant- Active hunters
How do you sedentary polychaete eat?
They are filter feeders
What are the tubes made of by polychaete?
Tubes may be made from calcium carbonate, a secreted paper-like material, or sand grains.
What does the term oligochaetes mean?
oligochaetes “few bristles”
Where do earthworms live?
Earthworms burrow in (and eat) rich, damp soil and leave their burrows at night to eat vegetation and to breed.
What significant roles do earthworms play in soil?
Aeration
Mixing
Adding organic material
What is bioturbation?
Mixing of the soil by biological activity
Where can earthworms be found?
Terrestrial soils and in freshwater
What are the excretory organs in Oligochaetas?
Nephridia- there is a pair in each segment, each of which occupies parts of two successive segments
The excretory system in oligocheats exits the body where?
an aperture called a nephridiopore
How does the excretory organs in oligocheats work
The system works by cilia drawing coelomic fluid into the nephrostome and selective reabsorbtion of salts and water occurs in the loops leaving only a dilute urine to be excreted to the outside.
How do earthworms reproduce?
Earthworms are hermaphroditic and mate by aligning their ventral surfaces together
How is sperm exchanged in earthworms?
seminal receptacle
Where are a majority of the class Hirudinea found?
Freshwater
How do leeches - of the class Hirudinea - eat?
Many leeches are carnivorous, but leeches are best known as blood-sucking ectoparasites.
How do leaches penetrate its host?
The leech penetrates its host using its jaws or proboscis and sucks blood with its powerful pharynx.