| Namespace | MPheno.ontology | Obsolete | false |
| description | any structural anomaly of the central core of the sperm flagellum, composed of a ring of 9 outer microtubule doublets surrounding a central pair; inner and outer dynein arms project from each of the outer 9 doublets, and these arms are responsible for generating the motive force of the flagellum; in addition, 9 radial spokes, each of which originates from 1 of the 9 outer microtubular doublet pairs, project inward toward the central pair in a helical fashion |