Internal and external indicators of male reproduction in the lesser long-nosed bat Leptonycteris yerbabuenae

(Uploaded by Plazi for the Bat Literature Project) Information on animal reproduction is critical for the application of wildlife conservation plans. The lesser longnosed bat (Leptonycteris yerbabuenae) is classified as threatened in Mexico; however, many aspects of its reproductive biology are still unstudied. The formation of a dorsal patch in males of Leptonycteris spp. during the mating period has been described and evidence suggests this patch is involved in reproductive behavior. We determined the male reproductive cycle of L. yerbabuenae over time based on the seminiferous cycle. We then related these internal indicators with 3 external indicators—testis size, dorsal patch size, and female/male ratio in the population. Finally, we evaluated whether the epididymis functions in long-term sperm storage. Bats were captured monthly and external indicators were registered. Three adult males were euthanized each month for the evaluation of internal indicators. We determined only 1 period of spermatogenesis per year beginning in September and completing in January. The seminiferous epithelium cycle showed 11 stages and 14 steps. Internal reproductive indicators were correlated with external indicators. External testis size and female/male ratio were positively correlated with dorsal patch size. A testis size of approximately 48.2 mm2 corresponded with the beginning of sperm production. The epididymis was not involved in long-term sperm storage. This study provides the 1st description in L. yerbabuenae of the annual timing of the male reproductive cycle based on histological characteristics, and also reports a relationship between the size of the dorsal patch and male reproductive function.