(of an organism or tissue) living in the absence of air or free oxygen. pertaining to or caused by the absence of oxygen.
Parakeets can breed year round if conditions are right in their environment. Normal breeding season begins early in the year and continues until fall. It is very rare to see parakeets mating, but a male and a female must mate to keep the eggs fertile.
Doctors have visited from Europe and a Syrian doctor is now working with a couple to try and grow sperm from the stem cells of a man with aspermia. In the rose-ringed parakeets, the period of aspermia in April had begun already before the endoscopic procedure. Testicular biopsy in psittacine birds (Psittaciformes): impact of endoscopy and biopsy on health, testicular morphology, and sperm parameters.