[Abortive spermatogenesis in the hybrid duck (cross of male Anas platyrhynchos and female Cairina moschata). Ultrastructural study].

The ultrastructural study of the abortive spermatogenesis of the hybrid drake (cross: male Anas platyrhynchos L. X female Cairina moschata L.) shows the following characteristics: 1) deep anomalies during the pachytene stage (meiotic prophase) where the chromosomes form more or less irregular packs close to the nuclear enveloppe; 2) the total lack of 2nd spermatocytes and in their place were found: --either some cells with lobed or fragmented nuclei in a cytoplasm filled with numerous annulate lamella, lipid droplets and centrioles, --or necrosing cells, with vacuolised chromatin close to the inner side of the nucleus and with abundant smooth endoplasmic reticulum vesicles and dark mitochondria; 3) numerous Sertoli cells overloaded with lysosomes. The mitochondria of the spermatogonia, the basal membrane of seminiferous tubules and the Leydig cells have the same structure that exists in the fertile Barbary drake testis.