Morphological variation of the cuticle that may result from mucus. A Smooth cuticle B–C Wrinkled cuticle D–E Cracked surface of cuticle F Areole-like structures on the anterior end of the cuticle G–J Indentations on the G–I mid-body and J anterior end of the cuticle surface. Scale bars 100 µm (A), 10 µm (B), 50 µm (C–E), 100 µm (F), 20 µm (G), 100 µm (H), 10 µm (I), and 100 µm (J).