lect 9 & 10 (annelida)

1

earthworm (oligochaete)

2

leeches (hirudinea)

3

sedentary polychaetas

4

errant polychaetas

annelida is a __ and a closed circulatory system

eucoelomate

what’s the synapomorphy of Annelida?

• used for gripping, sensory & defense

• made from chitins & other proteins

chaetae

what is the circular muscle used for?

elongation

what is the longitudinal muscle used for?

shorten

pharynx, crop or gizzard:

• specialized storage (temporary)

• flexible

crop

pharynx, crop or gizzard:

• extra muscle

• high mechanical breakdown

• pulls food in

pharynx

pharynx, crop or gizzard:

• extra muscle

• physical grinding of food (since no jaw present)

gizzard

oligochaeta reproduction

hermaphroditic, internal fertilization (clitellum)

what are those?

leeches (hirudinea)

what structures were lost in leeches?

septa, chaetae & blood vessels (open circulatory system)

what structures were gained in leeches?

suckers, jaw, teeth

leech reproduction:

hermaphroditic, internal fertilization (similar to oligochaete)

sedentary polychaetes are entirely __

marine

what are those?

sedentary polychaetes

what are those?

errant polychaetes

errant polychaetes have __ which is a tissue extension used for respiration, locomotion, defense & mechanosensory

parapodia

polychaete reproduction is __ (have trocophore form similar to molluscs)

gonochoristic, broadcast spawners