Scanning electron microscopy revealed that the gill arch surface from juveniles of Mugil platanus Günther, 1880 is similar to that reported for others euryhaline teleosts. Two filament rows (about 41-49 filament per row) extend posteriorly, and two rows of rakers (about 42-46 rakers per row) extended anteriorly from each arch. Respiratory lamellae protrude along both sides of each filament (37/mm), from the base to the apex. The distribution, sizes and structure of various surface cells were also described. Except for the respiratory lamellae, the surface of whole gill arch is covered by a mosaic of pavement cells, which measure about 6,94X4,61µm and exhibit concentrically arranged surface ridges. The anterior pharyngeal surfaces of the raker of the first arch and the ventral part of the second, smooth secondary projections are present which are replaced by spiny secondary projections on the dorsal part of the second arch, and entire third and fourth arches. Taste buds are especially prominent between smooth projections. Apical ciypts of chloride cells oceur mostly at the afferent surface of the gill filament.
Gill arch; Mugil platanus; morfology; surface ultrastructure