Morphology of the lingual apparatus of the Swiftlet, Aerodramus fuciphagus (Aves, Apodiformes, Apodidae)

The Swiftlet, Aerodramus fuciphagus Thunberg, 1812 (A. fuciphagus) is known for its edible nest building ability. The present study was conducted to examine and describe the morphology of lingual apparatus and associated structures which contribute to the nest building ability of the A. fuciphagus. Gross examination was done on the upper and lower jaw of the beak prior to tissue processing and sectioning. Following fixation and embedding, cross-sections of the lower jaw were made and stained with hematoxylineosin (HE) and observed under the light microscope. Microscopy examination revealed various structures within the lingual apparatus, which include stratified squamous epithelial lining, lingual salivary glands, hyaline cartilage and intrinsic skeletal muscle. Paired sublingual salivary glands were also observed. Taken together, these findings may provide some new insights in understanding the role of the lingual apparatus and the salivary glands of the Swiftlet (A. fuciphagus) especially in its unique nest building ability.