The flagellum of the motile spermatozoon of Nymphon leptocheles consists of a 12 + 0 axoneme. Centrioles with 12 triplets were also observed. The axoneme center was often occupied by a diffuse, sometimes rather electron dense material, but no central tubules, central sheath, or related structures were observed. No arms were present on the A tubule of the doublets, which were connected by a faint, circular line. In the basal region of the flagellum a complex of 12 Y-shaped connections between the flagellar membrane and the 12 microtubule doublets were found. © 1973 Academic Press, Inc.
van Deurs, B. (1973). Axonemal 12 + 0 pattern in the flagellum of the motile spermatozoon of Nymphon leptocheles. Journal of Ultrasructure Research, 42(5–6), 594–598. https://doi.org/10.1016/S0022-5320(73)80029-2