Morphological and ultrastructural studies of moose spermatozoa.

Epididymal spermatozoa from moose were studied in phase contrast, light interference and electron microscope. Some samples taken from cauda were diluted and frozen in liquid N. The motility of the sperms after thawing was good. The concentration of spermatozoa in cauda was calculated to 10 × 10 cells per µl. Morphologically the spermatozoa of moose were found to be quite similar to those collected from bulls. The length of the sperm head was found to be approx. 8.8 µ and the average maximal width 5.2 µ. The average length of the tail was 54.7 µ and the entire length of the spermatozoon varied from 60 to 64 µ. Compared with sperm cells from bulls the moose spermatozoa appeared to have a somewhat shorter and broader head and a slightly shorter tail. The migration of the cytoplasmatic droplets, which was found to be completed in caput, seemed to follow the same pattern as in bulls and boars. As found in these species there was also in the moose a higher frequency of secondary abnormalities in the spermatozoa from cauda than in those from the other parts of epididymis. Studies of the fine structure of the moose spermatozoa seemed to indicate that these are of the same type as the spermatozoa of bulls, rams and boars. In sagittal sections the sperm head was thin, but in contrast to the sperm cells of the species mentioned above no typical waist-like narrowing in the equatorial region was found. The equatorial segment also seemed to be less arched than in the spermatozoa from bulls, rams and boars. Otherwise, no principal difference was found between ultrastructure of the moose spermatozoa and that of the spermatozoa collected from domestic species.