Morphology and Ventilation of the Olfactory Organ in the Indo-Pacific Sergeant Abudefdufvaigiensis (Pomacentridae)

Abstract

The structure of the olfactory organ in Indo-Pacific sergeant Abudefduf vaigiensis has been studied by electron microscopy. The single olfactory opening (nostril) in Indo-Pacific sergeant is large; the olfactory rosette of an arrow-shaped type lies on the medial wall of the olfactory cavity, which is comparatively large in volume. The number of lamellae in the rosette is small; their peculiar form is associated with water flow regulation in the olfactory organ. Two ventilation sacs, large lacrimal and small ethmoidal, are attached to the olfactory cavity. The scheme of the olfactory organ ventilation is proposed. Changes in the main morphological structures of the olfactory organ with an increase in the body length of fish are observed.