• Korean Journal of Ichthyology
• /
• v.36 no.1
• /
• pp.40-47
• /
• 2024

The anatomy and histology of the olfactory organ of Monopterus albus was investigated using stereo microscopy, light microscopy, and scanning electron microscopy. The external structure of the olfactory organ exhibited closed anterior and posterior nostrils parallel to the skin surface. The interior structure consisted of a pipe-like chamber, and lower and upper accessory nasal sacs. The olfactory chamber was composed of the sensory and non-sensory epithelium, and an unidentified organ. The sensory epithelium of the pseudostratified epithelial layer was composed of olfactory receptor neurons, supporting cells, basal cells, and lymphatic cells; and the non-sensory epithelium of the stratified squamous layer contained stratified epithelial cells and mucous cells with acidic mucopolysaccharides. The presence of intraepithelial blood capillaries and abundant dermal vascularization in the sensory epithelium of the olfactory chamber may provide strong histological evidence that respiration occurs through the olfactory epithelium.