Figure 6 from: Kutschera U, Elliott J (2014) The European medicinal leech Hirudo medicinalis L.: Morphology and occurrence of an endangered species. Zoosystematics and Evolution 90(2): 271-280. https://doi.org/10.3897/zse.90.8715

Figure 6 - Intact (A) and fragmented (B) posterior sucker of an adult alcohol-preserved Hirudo medicinalis. The disk-shaped sucker is largely composed of muscle tissue containing numerous mitochondria. DNA-extractions for mt-sequence analysis (fragments of the gene CO-I) were performed from this part of the body that is not contaminated with the gut content of the blood-sucking annelid.