phylum annelida

what are common names for annelida?

segmented worms

around when did the annelida evolve?

around 500 million years ago

what type of symmetry does annelida have?

bilateral symmetry

are annelida segmented?

yes

do annelida have tissues?

yes

do annelida have a coelom?

yes

what are longitudinal muscles?

muscles that run up and down the body to shorten segments that aid in movement

what are circular muscles?

they surround the longitudinal muscles that lengthen muscles when contracted to aid in movement

what are setae?

bristles found on the ventral surface of the earthworm, used for traction and movement.

what is clitellum?

segments that secrete a mucus ring with reproductive cells

what are septa?

the tissue that separates segments

how do annelida move around?

my contracting their muscles to move the organism in an accordion-like manner

how do annelids get their nutrients?

by preying on small invertebrates or through filtering decomposing matter

how do segmented worms reproduce asexually?

the clitellum creates a mucus ring where an egg and sperm cell is created. then the egg is fertilized in the mucus ring and put into the soil to hatch

how do segmented worms reproduce sexually?

the clitellum creates a mucus ring where the egg or sperm is produced and then another worm rubs bodies with the worm to fertilize the egg

what makes up the annelida digestive system?

the mouth, pharynx, esophagus, crop, gizzard, intestines, and anus

what are the three classes of annelids?

oligochate, polychaets, and hirudinea

what are oligochates(earthworms) and where do they live?

the class of annelids that means “few bristles” because of the setae bristles that are used to move. they live in the soil

what are polychaets and where do they live?

they mean “many bristles” and live in the ocean. ex. plume worms, bristle worms, and sand worms

what are hirudinea?

they are part-time parasites with suckers on both sides of their bodies. they are found in ocean sands and reefs ex. leeches

how many species of annelids are there?

around 9000 species

how many hearts do annelids have?

5 hearts

how many germ layers do annelids have?

three germ layers, triploblastic

annelida are the first…

coelumates