Development of epidermal and mucosal galectin containing cells in metamorphosing leptocephali of Japanese conger

The epidermis of premetamorphic leptocephali of Japanese conger Conger myriaster consisted of only a few cell layers including congerin- (a galectin) containing club cells. The epidermis increased in thickness after metamorphosis, mainly due to a preponderant development of club cells. This suggested that the biological significance of congerins increased at this stage, which may be related to a change in life style. Epidermal mucous cells showed only limited distribution. Immuno-positive cells in the mucosal epithelia of the buccal cavity wall and oesophagus were not found in the youngest individuals. Though these cells were observed at the commencement of metamorphosis, the development of the epithelia and club cells was apparently retarded compared to that of the epidermis. No immuno-staining was found in the gills at any stages.