Lingual morphology of three urban molossid bats from South America: Filiform lingual papillae with somatosensory innervation

Bats have evolved a wide variety of dietary strategies. These diverse diets have driven significant morphological specialization of their tongues. This study focuses on the external and histological morphology of lingual papillae in three South American insectivorous bat species belonging to the family Molossidae: Molossus fluminensis , Molossus molossus , and Eumops patagonicus . Using scanning electron microscopy (SEM), conventional histological techniques, and immunohistochemistry, we identified four types of lingual papillae: filiform, scale‐like filiform, fungiform, and circumvallate. A distinctive lingual torus was observed in all three species, dividing the tongue into proximal and distal regions, with large circumvallate papillae present in the posterior region. Histologically, the tongues of these species exhibited a stratified squamous keratinized or parakeratinized epithelium and its lamina propria of connective tissue in the mucosa and a muscular layer of visceral striated muscle. Taste buds were identified in fungiform and circumvallate papillae. Immunohistochemical analysis revealed positive detection of neurofilament and S‐100 proteins, indicating the presence of somatosensory innervation and suggesting its potential role in sensory perception. Neurofilament‐positive nerve bundles were localized within the muscular layer and lamina propria of mucosa, while S‐100 immunoreactivity was observed in nerve bundles near the taste buds and lamina propria of mucosa of filiform papillae. These findings suggest that, despite the lack of taste buds in filiform papillae, they may serve a sensory function, aiding in the manipulation and retention of prey during aerial capture. This study contributes to our understanding of the morphological and functional adaptations of the lingual papillae in molossid bats.