Functional Anatomy of the Olfactory Organ of Fish and the Ciliary Mechanism of Water Transport

TLDR

The olfactory organ of tench is functionally divided into a vestibule and a gallery, whereas other fish species lack this subdivision and instead possess accessory olfactory sacs. Water currents are generated by oriented, symmetrical ciliary beats along corridor walls with appropriate spacing, or by a pumping mechanism in accessory sacs. Unidirectional water currents flow from vestibule to gallery through rosette leaf corridors, a sampling mechanism conserved across trout, carp, roach, catfish, eel, rockling, and dogfish.

Abstract

Abstract The olfactory organ of tench is functionally divided in a vestibule and a gallery. Experimental observations are presented indicating that an unidirectional watercurrent is created from the vestibule to the gallery via the corridors which are formed by the leaves of the olfactory rosette. The conditions for creating the watercurrents are: oriented and symmetrical beats of cilia situated on the walls of the corridors, and appropriate spacing of the corridors. This principle for water sampling is found in the olfactory organs of trout, carp, roach, catfish, eel, rockling and dogfish. In some other fishes studied the olfactory organs have accessory olfactory sacs and there is no subdivision in vestibule and gallery. In these organs the watercurrents are achieved by a pumping mechanism of the sacs.