Studies On The Taxonomy And Molecular Systematics Of Freshwater Planarian In China

The paper reports a new species of the genus Polycelis collected from Yangcheng County, Shanxi Province, China. The type specimens are deposited in the zoological laboratory, College of Life Sciences, Henan Normal University, Xinxiang, Henan Province.Polycelis Yangchengensis sp. nov.Living mature specimens were 12-17mm in length and 1.5².5mm in width, dark brown in colour. Eye-bands were "A" shape, consisting of 80-100 eye-spots. Anterior trunk of intestine had 6-10 lateral branches, and each posterior trunk provided with 12-16 branches. Ovaries were of middle-sized compact masses. Testis were much in quantity and big in volume.They were distributed from venter to back, extending from the level of the ovaries to the base of the pharynx, about 50-60. Penis consisted of a moderate size penis pulb of strong muscular property and a papilla of comparatively strong muscular property. There was no bulbar cavity and the penis papilla was thin and long, being shaped awl,opening to male antrum on tip of it. The copulatory bursa was a rectangular or elliptic sac, behind pharynx. Bursa stalk which was covered by a coat of strong circular muscle was thick in intial ,then become thin ,at last return thick again,opening to common reproductive antrum.The type specimens were collected from the spring in Renbigou and Chengqianggen, Yangcheng County (112° 09.133' E, 35° 16.398' N), Shanxi Province , China.The genome DNA of Dugesia japonica collected from Erlang Temple, Lushan County, Henan Province was extracted with the kit bought from Shanghai Sagon Bioengineering Company. According to the experimental conditions of Williams et al, the reaction conditions for RAPD analysis of freshwater planarian in China were optimized. Through comparision the optimum conditions are as fellows: In 25μl reaction volume, 20ng template DNA, 37℃ annealing temperature, 0.2μmol/L primer, 2.0mmol/L Mg²⁺ and 200μmol/L dNTP.36 primers were selected from 80 10-Mer random primers . With 27 of them, freshwater planarians collected from nine localities in China including Mt. Wuchao, Hangzhou City were analysed by RAPD according to the optimized reaction conditions. 314 bands were scored for the 9 samples, out of which 312 Hand positions were polymorphic.The ratio of polymorphism was 99%. Genetic distances between each of the samples were caculated and cluster analysis was used to generate a dendrogram showing phylogenetic relationship among them. The result demonstrates that Dugesia japonica collected from Weiyuanhou, Yangcheng County, Shanxi Province ,Mt. Yuntai, Xiuwu County and Shijiabei, Jiyuan City, Henan Province are closest in relationship. Dugesia japonica from Erlang Temple, Lushan County , Shashi, Xin County and...