Phylum annelida
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Transcript of Phylum annelida
The Segmented Worms
PHYLUM ANNELIDA
INTERNAL ANATOMY
INTERNAL ANATOMY
https://www.youtube.com/watch?v=u9HHS1uPFSo
• Note the adaptation of the mouth to the parasitic niche of the leeches
• Note also the segmentation which makes it similar to the other annelid worms
HIRUDINEA – THE LEECHES
• This leech has an anterior sucker for feeding and a posterior sucker for attachment
• https://www.youtube.com/watch?v=ye4N2ZeJESA
HIRUDINEA – THE LEECHES
• Note the parapodia
• Parapodia are expanded groups of structures (including lobes and setae) used for locomotion and gas exchange
• Note also the specialization of segments and well developed cephalization
• https://www.youtube.com/watch?v=kIoN2PCvL4o
• https://www.youtube.com/watch?v=UuApLH8rlwY
CLASS POLYCHAETAE
• Note the clitellum – a reproductive structure that will form a protective case for the eggs & larvae
• Note the specialization of anterior and posterior segments
• https://www.youtube.com/watch?v=uO4lkv-jLRs
CLASS OLIGOCHAETAE – THE EARTHWORMS
• Earthworms are monoecious (hermaphroditic), but cannot self-fertilize
• https://www.youtube.com/watch?v=bFpblBf1dfE
EARTHWORM REPRODUCTION