Ultrastructure of the spermatozoon in Pampus argenteus

Ultrastructure of Pampus argenteus spermatozoa was investigated by means of scanning electron microscopy(SEM) and transmission electron microscopy(TEM).Spermatozoa of P.argenteus consisted of a head,a midpiece and a tail(flagellum).The spermatozoa,39.51±1.64 μm in total length,was asymmetrically shaped.The head,with a coarse surface,was 1.98±0.30 μm in total length.Main structure of the head was nucleus and centriolar complex.The nucleus,of spherical shape,was located at the ventral part of the head.The nucleus consisted of electron dense chromatin materials and irregularly netlike gap.The proximal centriole,which is made up of nine triplets of peripheral microtubules,and the distal cintriole were arranged at a right angle to each other.The midpiece of spermatozoa includes sleeve and mitochondria.The sleeve,which contained 4-5 mitochondria and a few vesicles,was connected to the posterior end of the nucleus.Tail was slim and long,37.52±1.68 μm in total length.The end part of the tail was much thinner than the anterior part.The main structure of the tail was axoneme,of typical 9+2 model.The tail had lateral fins,which were undulating and arranged asymmetrically.