title: The fine structure of spermatozoa of Hydrolagus colliei (Chondrichthyes, Holocephali).
abstract: The ultrastructure of spermatozoa in Hydrolagus colliei is described. Basic similarities of structure to the sperm of the related elasmobranch fish are noted. The most significant features of sperm structure in Hydrolagus that differ from those of elasmobranch fish occur in the tail. The axoneme is eccentrically located and forms a double helix with a single longitudinal column. A second longitudinal column is reduced to a short remnant at the base of the tail. Microtubules within the axoneme are also helically disposed, a feature that is consistent with the rotating motion of the sperm. Abundant glycogen reserves are stored along the length of the tail.
mesh_terms: D000818:Animals; D005399:Fishes / Q000033:anatomy & histology*; D008297:Male; D008854:Microscopy, Electron; D013094:Spermatozoa / Q000648:ultrastructure*