Histo-morphological features of the efferent ductules of the African straw-coloured fruit bat (Eidolon helium)

Abstract

Introduction: The African straw-coloured fruit bat plays important roles as pollinators, seed dispersers and important carrier of zoonotic diseases. It is a non-hibernating seasonal breeder whose reproductive biology had received little attention. The aim was to study the histomorphology of the efferent ductules of Eidolon helvum using 10 adult male bats. Methods: The efferent ductules were obtained from the adult bats, fixed by immersion in neutral-buffered formalin and prepared for histology and histochemistry. Results: The result showed that the entire epididymis was enclosed by the thick dense regular connective tissue, tunica albuginea. Within the connective tissue, tubules of efferent ductules occurred in lobules. These lobules were separated from each other by connective tissue trabeculae. The efferent ductules are tiny tubules that connect the rete testis to the initial segments of the epididymis. Each efferent ductule was lined by a simple columnar epithelium of two cell types, containing the ciliated and the non-ciliated cells. The non-ciliated cells were more numerous exhibiting oval shapes, basally located euchromatic nuclei with prominent nucleoli. The ciliated cells were fewer and appeared as dark cells with oval to elongated, centrally or apically located heterochromatic nuclei. Cilia projected from the apical surfaces of the ciliated cells into the lumen. PAS/Alcian blue staining showed presence of PAS positive secretions in the apical cytoplasm of the non-ciliated cells. Significance: These findings indicate that the morphology of efferent ductules of the African straw-coloured fruit bat have similar morphology with most mammals but differ from those of insectivorous bats.