Chinese Giant Salamander Kidney And Gonads Of Embryonic Development Of The Morphological Study

Chinese giant salamander (Andrias davidianus) referred to as the giant salamander, is the State ClassⅡKey protection of wild animals, is the largest amphibians in the the world. As a representative of Caudata amphibian animals, is the study of vertebrates from aquatic to terrestrial evolution of good material. In this paper, the Chinese giant salamander as the research object, using the research methods of general morphology, mainly on the development of giant salamander kidney. The main results and conclusions are as follows:1. At the 1 day after hatching, the renal tubules can be divided into proximal tubule and distal tubule. At the 91 day after hatching, renal differentiated into two regions, one region located near the middle of the ventral kidney, about 1/5; another area in the dorsal and ventral sides of kidney, about 4/5. At the 112 day after hatching, kidney bodies were observed, making the renal cortex and medulla with the earliest differentiation. At the 343 day after hatching, collecting duct can be observed. At the 427 day after hatching, the differentiation of renal cortex and medulla is more evident. At the 511 day after hatching, the number of renal corpuscle and renal tubular cortical are increased significantly, collecting duct are also increased. Kidney development process is divided into four stages. The functions of Chinese giant salamander renal units suited to the habitat.2. At the 91 day after hatching, based on gonad morphology and location of the cells can be divided into two cell types, the peripheral and central.the central cells are germ cells. At the 175 day after hatching, the major changes have occurred in that period is the differentiation of primordial follicles. At the 343 day after hatching, a small gap within the gonads or the appearance of large cavities. Some cells deep into the substance of the gonad gonad divided into less obvious 3～4 leaf, suggesting the testis has been differentiated. At the 91 day after hatching, has genital ridge differentiation. At the 175 day after hatching, can be observed ovary. At the 343 day after hatching, can be observed the testis. Indicating that the genital differentiation of giant salamander, females earlier than males.