Comparative Morphology of Fish Olfactory Epithelium—III: Cypriniformes

Abstract

The olfactory rosettes of 15 species of the Cypriniformes were studied by scanning and transmission electron microscopy. Olfactory lamellae are similar in surface features to one another among 15 species examined. A feature specific to the Cypriniformes is a patchy distribution of dense cilia. The ciliary patches are scattered not only on the olfactory lamellae but on the floor of the olfactory chamber. The ciliary patch consists of a cluster of type 1 ciliated cells (cells giving off numerous cilia from the wide and fiat free surface.) In the peripheral zone along the distal margin of each lamella, the ciliary patches are surrounded by non-ciliated indifferent epithelium. In the central to basal region of each lamella, the ciliary patches are surrounded by sensory epithelium which is composed of type 2 ciliated cells (cells protruding a round cell apex from which 4–6 cilia project radially), microvillous cells (cells having a tuft of many microvilli) and supporting cells. Rod cells which protrude a short rod from the free surface are occasionally found in the sensory epithelium. © 1978, The Japanese Society of Fisheries Science. All rights reserved.