Spermatozoa Characteristics in Six Psittacine Species Using Light Microscopy

Even though breeding of companion birds has increased continuously for years, the fecundity assessment of birds has hardly been acknowledged. Knowledge of the structure of spermatozoa is crucial for evaluation of the basic reproductive biology of any species as well as for phylogenetic research and cladistic analyses of internal relationships. Spermatozoa of six different psittacine species (Nymphicus hollandicus, Myiopsitta monachus, Agapornis roseicollis, Melopsittacus undulatus, Tanygnathus lucionensis, Guarouba guarouba) were examined using light microscopy. Head length (nucleus including acrosome), head width, midpiece length and tail length were measured and documented. Significant differences were obvious among almost all of the species for almost all four parameters. However, in all the six species a significant moderate correlation between spermatozoa midpiece lengths and tail lengths (r = 0.535, p [less-than or equal to] 0.01), spermatozoa head lengths and midpiece lengths (r = 0.508, p [less-than or equal to] 0.01) as well as tail lengths (r = 0.472, p [less-than or equal to] 0.01) was found. The present results confirm that spermatozoa of cockatiels have shorter heads and midpieces than the other psittacines examined in this study. Spermatozoa characteristics in the monk parakeet, blue-naped parrrot and golden conure are previously unreleased and documented for the first time.