[Habitat characteristics of Andrias davidianus in Zhangjiajie of China].

By the methods of field investigation and laboratory analysis, the habitat characteristics of Chinese giant salamander (Andrias davidianus) in Zhangjiajie Giant Saramander National Nature Reserve were studied from July to August in 2006-2008. In the study area, the inhabited reaches of A. davidianus were characterized by moderate altitude (373 +/- 97 m), relatively small river width (6.39 +/- 2.13 m) and depth (1.07 +/- 0.53 m), lithoid substrate with more gravels or rocks, irregular river bed, stony river bank with more scrub vegetation and larger coverage ( > 50%), steeper bank gradient (58 degrees +/- 17 degrees), higher water flow rate (0.33 +/- 0.08 m x s(-1)), and weaker anthropogenic disturbances. There were many burrows (4 +/- 2 ind x 100 m(-1)) in the habitat, and the water flow rate in the burrows were relatively low (0.22 +/- 0.10 m x s(-1)). The waters in the habitat were with high DO (7.23 +/- 0.85 mg x L-(-1)), low COD (4.00 +/- 2.51 mg x L(-1)), low TN (0.11 +/- 0.15 mg x L(-1)), moderate total hardness (137.16 +/- 67.69 mg x L(-1)), and lesser coliform groups (3419 +/- 3407 ind x L(-1)). Crabs were the most important food organisms affecting the A. davidianus population in the study area, followed by shrimps.