Journal of Applied Animal Research

The main ultrastructural properties of gill chloride cells in Mugil aurata from south of Caspian sea was investigated. These cells are packed with other cells in filament epithelia and are divisible into dark and light cells. Quantitatively the two cells are notably different in membranous network and the number of mitochondria. The tubulo-vesicular in both cells comes in close contact with mitochondria and nucleus. The close relation was observed between the chloride cells and accessory. This indicates that chloride cells are communicated with external milieu via the channel system of accessory cells.