(b) : In salamander, kidneys (mesonepheric) are the excretory organs and the excretory matter is urea. In Labeo, mesonephric kidney is the excretory organ and excretion is ammonotelic. Peacock has metanephrid kidneys with excretory matter being uric acid. In housefly, excretion takes place by Malpighian tubules. Excretory waste is uric acid chiefly.