Reproductive biology of the male sheath-tailed bat, Taphozous longimanus (Emballonuridae) from India.

The seasonal chronological events of the reproductive cycle in the male sheath-tailed bat T. longimanus and changes in structure and function of accessory sex organs were studied at Varanasi (latitude: 25 degrees N, 83 degrees E). The first peak of spermatogenesis was observed in September with the appearance of spermatozoa. The spermatogenic arrest in winter dormancy (December) was followed by a second peak of spermatogenesis in January. This period coincides with ovulation in females. The third peak of spermatogenesis started after regression in late April, and completely regressed tubules were found after May. The cycle of accessory sex gland complex generally paralleled the testicular cycle, reaching maximum hypertrophy from September to January and again in late April. Thereafter, the accessory sex glands involuated. Spermatozoa were present in the cauda epididymidis throughout the year. The reproductive cycle in family Emballonuridae varies with changes in latitude, and this was so even in members of the same species. The presence of spermatozoa in the cauda epididymidis throughout the year is an interesting feature in the reproductive cycle. Temperature and photoperiod do not play a regulatory role in reproduction in T. longimanus.