宁陕齿突蟾蝌蚪的生物学特性

Biological Characteristics of tadpoles of the Ningshan alpine toad Scutiger ningshanensis Fang,1985

The Ningshan alpine toad Scutiger ningshanensis Fang, 1985 is a rare endemic toad living in alpine area of the Qinling Mts. in China. It has the most northeastern distribution of any species in the genus Scutiger. Only the holotype and allotype have been collected for the last 20 years during field surveys, and its biology is poorly studied. This report confirms that a special type of tadpole found in the type locality belongs to S.ningshanensis. A remarkable and uniform character of the tadpole is the presence of a golden “Y” shaped stripe on the posterior part of dorsum, similar to tadpoles of species of genus Vibrissaphora and Oreolalax lichuanensis (with a “U” stripe). The tadpole is morphologically typical of those which inhabit streams (Orton’s type Ⅳ larvae with LTRF I:5-5/I:5-5), but exhibits no special morphological adaptations for life in torrent streams. The tadpoles usually remain on or near rocks or sand and are positively phototactic. From an analysis of the population ecology of the tadpoles, it appears that the reproductive period of the toad is from June to August,and that hatching occurs between August and September. Tadpoles complete metamorphosis in about three years.

The Ningshan alpine toad Scutiger ningshanensis Fang, 1985 is a rare endemic toad living in alpine area of the Qinling Mrs. in China. It has the most northeastern distribution of any species in the genus Scutiger. Only the holotype and allotype have been collected for the last 20 years during field surveys, and its biology is poorly studied. This report confirms that a special type of tadpole found in the type locality belongs to S. ningshanensis. A remarkable and uniform character of the tadpole is the presence of a golden ＂Y＂ shaped stripe on the posterior part of dorsum, similar to tadpoles of species of genus Vibrissaphora and Oreolalax lichuanensis （with a ＂U＂ stripe）. The tadpole is morphologically typical of those which inhabit streams （Orton＇s type IV larvae with LTRF I： 5-5iI： 5-5 ）, but exhibits no special morphological adaptations for life in torrent streams. The tadpoles usually remain on or near rocks or sand and are positively phototactie. From an analysis of the population ecology of the tadpoles, it appears that the reproductive period of the toad is from June to August, and that hatching occurs between August and September. Tadpoles complete metamorphosis in about three years .