الفهرس 
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Abstract
The structural organization of the olfactory and gustatory organs in silver carp was investigated. The olfactory organs are consisted of two bilateral olfactory chambers occupied by oval olfactory rosetta made up of 40–44 lamellae. The surface epithelium of each lamella is differentiated into a central sensory segment and a peripheral non-sensory segment. The first one is of mixed sensory and nonsensory epithelia; while the other, is of purely nonsensory epithelia. The sensory epithelium is represented as separated islets within the nonsensory epithelia. The separate sensory islets are formed of four types of sensory cells differentiated according to their apical dendrites into flagellar, microvillar and rod cells in addition to crypt cells. The outer surface of the indifferent and supporting non-ciliated cells is equipped with microridges forming finger-print like pattern. Taste organs (taste buds) are widely distributed in the lips and nostrils of silver carp; they are embedded and not protruded over the epidermis (third type). Taste buds are formed of either pale or dark spindle-shaped sensory cells surrounded by supporting cells. from each sensory cell monovillus or numerous microvilli processes originate. from the outer surface of epithelial cells surrounding taste pores, emitted microridges arranged in finger-print like pattern. The investigations were followed by the study the effect of sublethal concentration (1/10 LC50) of Carbofuran on the studied chemosensory organs. This Carbamate nematicide which is one of the most popular used pesticides resulted in marked progressive pathological alterations in both olfactory epithelia and taste bud.