Download Class Hirudinea

Class Hirudinea
The leeches
1. Body structure
 Fixed number of segments = 34
 No setae
 No septa
2.
Habitat
 Most freshwater
 Some ectoparasites
Figure 1
3.Feeding
 Mouth : proboscis or pharynx with
three sets of jaws with teeth
 Anterior & posterior suckers (ectoparasites)
 Digestion: slow, no enzymes, bacteria digest blood
 3 chemicals in saliva:
1. anticoagulant – prevents blood clotting
2. antibiotic – prevents infection
3. anesthetic – causes numbness
4.Reproduction
 Clitellum present only during breeding season
5. Medicinal Use –
 stimulate blood flow for reattachment
of severed appendages