Histo and Ultrastructural Aspects Concerning Renal Corpuscle in Fulica atra and Gallinula angulata (Aves: Gruiformes)

The avian renal system is quite unique among vertebrate kidneys. Birds have paired kidneys located within a cavity formed by the ventral surface of the synsacrum. Kidneys of coots (Fulica atra) and lesser moorhen (Gallinula angulata) were removed from the abdomen and subjected to histological and ultrastracture studies. The result showed that coots tend to have a greater medullary thickness than lesser moorhen. The renal corpuscle was smaller in size and larger in number in lesser moorhen than in coot. In lesser moorhen collecting tubules was much larger in size and number than in Coot, they lined by pale cells and cuboidal shape and were intermediate in size between the proximal and distal convoluted tubules. In addition, podocytes process was larger in lesser moorhen than in coot. In this investigation, relatively large medulla found in coot seems to be the adaptive advantage of species which have to mitigate scarcity of water or excessive evaporative water loss by maximum renal water conservation during migration for long distances. On the other hand, differences in kidney histology can be correlated with certain parameters of the water economy in birds.