MaleMusFIG 22: The spicules.

Illustration of the adult male tail region featuring the spicules, dorsal view. Sexually dimorphic muscles are underlined.(v/dsrL) Ventral and dorsal spicule retractors,(v/dspL) ventral and dorsal spicule protractors; (adp) anal depressor. (Adapted from Sulston et al., 1980.)