Abstract
The taste-buds of various teleost fishes consist of four cell types including two different receptor cells, which differ in their cytoplasmic density (“light” and “dark” cells) and the quantitative composition of their organelles. The light cells are characterized by generally well orientated systems of supra-nuclear microtubules and smooth endoplasmic reticulum. The dark cells contain mainly electron dense granules, bundles of tonofilaments and cisterns of rough endoplasmic reticulum. Both cells reach the apical surface of the epidermis, where they bear a few stout microvilli. Occasionally deep invaginations of the apical plasmalemm extend into the cytoplasm. At their base both cell types are in direct contact with nerve endings. The morphology of the synaptic region varies, e.g. membrane thickenings are relatively infrequent; a constant feature however being accumulations of clear visicles in the receptor cells.
