The coronal sections of the contracted posterior sucker.

<p>Four muscle fibers can be observed: long longitudinal muscular fiber (LLMF), short longitudinal muscular fiber (SLMF), circular muscular fiber (CMF), and radial muscular fiber (RMF). Minor muscle fibers can also be observed in the area beneath epidermal tissues of the sucker and body joints. SE: stratified epithelium, An: annuli of the body, GE: glandular elements. The scale bars = 200 μm in Fig 7B and 500 μm in Fig 7C and 7D.