Cellular organization of the olfactory epithelium during growth, maturation, spawning and post-spawning phases of freshwater catfish, Eutropiichthys vacha (Hamilton, 1822) (Teleostei: Siluriformes)

Cytological status of olfactory epithelium during different reproductive phases of Eutropiichthys vacha (Hamilton, 1822) were described by light microscopy. The olfactory organ was composed of various lamella contained two principal layer: olfactory mucosa and central core, radiated from midline raphe. A sharp divergence existed between the mucosa of the olfactory lamella and raphe. The olfactory mucosa was distinguished into sensory and non-sensory epithelium, which consisted of polymorphism of receptors, supporting, labyrinth, mucous and basal cells. The central core was made up of loosely disposed connective tissue, nerve fibres and blood capillaries. A well-developed basement membrane was clearly distinguishable in between the olfactory epithelium and central core. The seasonal changes of the olfactory mucosa during growth, maturation, spawning and post-spawning phases was characterized by considering the tallness and architecture of the receptor cells as main criteria along with commute cellular features and staining patterns of different cell types. The structural components of the olfactory epithelium were correlated with the olfaction in the life of fish concerned.