Annelida Flashcards
What type of worms are phylum annelida
segmented worms
why type of worms are included in phylum annelida
earthworms, polychaete worms and leeches
what is another word for segmentation
metamerism
what is first seen in annelids
coelom
between 2 mesodermal layers
why are annelids more mobile than nematodes
hair like structures called SETAE (except leeches)
Sometimes located on paddle-like appendages called parapodia.
Are annelids generally parasitic
no, they are just invertebrates
what are the subgroups of phylum annelida
class oligochaeta (earthworms)
class polychaeta (marine worms)
class hirudinea (leeches)
What are the important evolutionary changes in annelids
- coelom between 2 mesodermal layers
- big cerebral ganglia for touch and pressure
- blood vessels: open and closed closed means only carried in vessels
- pulsating vessels that move blood
- excretory system: metanephridia
how can you compare metanephridia to nephrons of mammals
in our early embryonic life we have this primitive nephrostome as kidney then we develop Bowmans capsule as we grow
coelomic fluid filtered, useful solutes reabsorbed (like in mammals) urine excreted
how do earthworms reproduce
hermaphrodites but avoids self fertilisation
- spermatozoa exchanged when fem+mal glued together
- when mating done, slime tube formed CITELLUM full of liquid
- earthworm moves forward out of the tube, tube pass fem pick egg, tube pass male pick sperm
- fertilzed eggs develop in closed citellum
latin name for leeches and features
Hirudo medicinalis
- anterior and posterior sucker
- chitinous sharp teeth
- produces painkillers in saliva so bite does not hurt
- dont treatment disease as they dont vomit
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How can leeches be used in medicine
after skin graft, they can stimulate circulation or clean blood clots
