Structural and ultrastructural differentiation of cell types in the gills of the tench (Tinca tinca, L.).

This study used 22 tench of 25-30 cm in length and weighing roughly 200 g. After sacrifice, the gill arch was extracted and fixed in 5% glutaraldehyde for structural, ultrastructural and morphometrical study. Tench gills consist of primary lamellae which are perpendicular to numerous secondary lamellae in which the respiratory barrier is located. A study was made of the structures which make up that barrier and of the multi-layered epithelium situated in the interlamellar space, which is closely linked to maintaining of internal balance in the fish.