Comparative anatomy and histology of the prostate gland in three neotropical vespertilionid bats (Chiropteran: Vespertilionidae).

The prostate gland is a principal accessory reproductive organ whose secretions are essential for sperm survival and viability. In Chiropteran, its morphology varies widely, yet interspecific anatomical and functional differences remain poorly understood. This study describes and compares the gross anatomy, histomorphology, and histochemical profile of the prostate in three Neotropical vespertilionid bats-Neoeptesicus furinalis, Myotis levis, and Lasiurus blossevillii-across two climatic seasons (cold-dry and warm-wet). Prostates from 20 adult specimens were analyzed using anatomical description, standard histology (H-E), and histochemistry (periodic acid-Schiff [PAS]-hematoxylin). Anatomically, a fundamental intergeneric difference was observed: N. furinalis exhibited two regions (ventral and dorsal), whereas M. levis and L. blossevillii showed a tricompartmentalized prostate (ventral, dorsal, and dorsolateral). All species presented a pseudostratified epithelium. Histochemically, the ventral lobe was consistently PAS-positive, but its mode of secretion differed-holocrine in N. furinalis and M. levis, and apocrine in L. blossevillii. Seasonal patterns also diverged: N. furinalis and M. levis showed marked variation in prostatic activity, whereas L. blossevillii remained active year-round. These results demonstrate pronounced intergeneric divergence in prostate organization and secretory dynamics, suggesting that the prostate gland plays a central, species-specific role in mediating reproductive strategies in response to environmental conditions in Neotropical vespertilionid bats.