Functional morphology of the suckers and teeth of the medicinal leech Hirudo verbana Carena, 1820 (Annelida; Clitellata; Hirudinida): A scanning electron microscope study

In this study, the triple jaws and suckers of the leeches belonging to the Hirudo verbana Carena, 1820 (Annelida; Clitellata; Hirudinida) were examined using the stereomicroscopy and scanning electron microscopy. In H. verbana, suckers are seen on the first annulus and last annulus of the body. The mouth opens in the center of the front suction cup, and behind this opening is a movable triple jaw apparatus with many teeth. The posterior sucker disc consists of the last seven body segments and lacks an opening. The shape of the jaw is trignatous. The pharynx is equally located around of the three muscular jaws. The jaws are muscular covered with cuticle and carry a row of teeth arranged at the tip. In this study, it was determined that secretory canal holes were identified between the teeth. The results show that the size of teeth determines long‐term bleeding so revealing the structure and working mechanism of the teeth has importance for medicinal leeches. At the same time, the difference of teeth and jaw structures of leeches may be a criterion in the classification of medicinal leeches. The triple jaws and suckers of the leeches belonging to the Hirudo verbana were examined, using the stereomicroscope and scanning electron microscopy. There is a mouth opening in the center of the front suction cup, and behind this opening is a movable triple jaw apparatus with many teeth.