annelida Flashcards
What is the distinguishing characteristic of annelida?
segmented bodies, meaning body elements may show repetition (metamerism)
What type of support system is found in annelida?
hydrostatic skeleton
What type of digestive system is found in annelida?
complete
what type of circulatory system is found in annelida?
closed
How many tissue layers are found in annelida? what is the name of the body cavity?
they are triploblastic and possess a coelom
What is the nervous system of annelida like?
a dorsal brain and a ventral nerve cord
How do annelids reproduce?
annelids are hermaphroditic, meaning they are monoecious
What class of annelida can sandworms be found in?
polychaeta
What are the distinguishing features of polychaetes?
members of polychaeta have side flaps called parapodia that contain the bristle-like setae, they also have a well-differentiated head
How do members of polychaeta feed?
some suspension feed, some carnivorous
Where can the oldest segments of annelida be found?
closest to the head
Where can the youngest segments of annelida be found?
farthest from the head
What are some distinguishing characteristics of the subclass oligochaeta, or class clitellata?
these annelids lack parapodia so rely on the entire epithelial surface for gas exchange. they also possess the clitellum, a tool for reproduction
What is the purpose of the parapodia?
parapodia are modified in different species, however they are essential for gas exchange and respiration in all
What is the function of setae in annelids?
locomotion
What is the name of the fleshy flap that covers the mouth of oligochaetes?
prostomium
What is the function of the pharynx in earthworms?
pumping in soil
what is the function of the crop in earthworms?
temporary storage of food before passing into the gizzard
what is the function of the gizzard in earthworms?
location where soil is mechanically ground up and food is separated from inorganic material
What is the function of the seminal vesicles in earthworms?
lobed organs that extend dorsally around each side of the esophagus that store maturing sperm
what is the function of the seminal receptacles in earthworms?
ventrally located organs that receive sperm during copulation and store until needed to fertilize eggs in cocoon
How do you located the nephridia in earthworms?
paired excretory organs located in body wall that release waste fluis; hard to see unless under microscope
What are the partitions between each segment in earthworms called?
septa
What is the function of the typhlosole in earthworms?
to increase surface area of intestine
Do annelids possess a cuticle?
yes, however unlike nematodes and the rest of ecdysozoa, annelids do not shed their cuticle
What are the distinguishing features of subclass oligochaeta, class hirudinida?
these are typically ectoparasites (leeches) that are fluid feeders. they possess posterior and anterior suckers
