A NEW SPECIES OF THE GENUS GIEYSZTORIA (PLATYHELMINTHES,RHABDOCOELA,DALYELLIIDAE) FROM CHINA

A new species,Gieysztoria wuyishanensis Wang et Lai,sp.nov.,of the genus Gieysztoria (Platyhelminthes,Rhabdocoela,Dalyelliidae) was described in this paper.Holotype PLA-G0001,Jiuqu Stream (27°44'N,118°1'E),Mt.Wuyi,Nanping City,Fujian Province,China,May 2005.Paratype PLA-G0002,same data as holotype.All the type specimens were collected by ZHANG Yu (College of Life Science,Shenzhen University) and deposited in National Zoological Museum,Institute of Zoology,Chinese Academy of Sciences,China.Description (Figs 1-9).Body length 1290-1410 μm.This species has a slightly applanate head and a long tapering tail.It's cylindrical-like at the middle of the body,with circular and brown spots over the dorsal side.The sclerotic stylet (length 240 μm) possessed the typical characteristics of subgroup Falcatae within Inaequales of genus Gieysztoria.This new species consisted of two stalks (sk) of different lengths which were interconnected by a broad cross-connection (cc).5 spines extending out towards posterior end of the 2 stalks,and according to the nomenclature which was established by Van Steenkiste et al.,2012 of different spines,they were named s1,s2,s3,s6 and s7,respectively.In particular,s2 was the main diagnostic characteristic of Falcatae.The s2 had a thick and strong hooked spine,with a similar discription to raptor claw.Two testes are ventro-laterally located in caudal body,and usually at both side of the intestine.Habitat.The new species was found among the waterweeds in Jiuqu Stream,Mt.Wuyi,Fujian Province,China.Water temperature was 18℃;pH7.8.Etymology.The species was named after the locality Mt.Wuyi where the type specimens were collected;adjective.Remarks.Gieysztoria wuyishanensis sp.nov.,a species belonging to Rhabdocoela,Dalyelliidae,Gieysztoria,Inaequales,Falcatae,was reported in China for the first time.There have been 9 species of Falcatae recorded worldwide and the new species had maximum similarity to G.stokesi (2012) comparing the stylet morphology.However,there were still some differentia.The stylet of G.stokesi was 115μm long with 4spines (s1,s2,s3 and s6),while the stylet of G.wuyishanensis Wang et Lai,sp.nov.was 240μm long with 5 spines (s1,s2,s3,s6,s7).The number of spines as well as the overall length was sharply different.Compared with G.stokesi,G.wuyishanensis sp.nov.had 1 more spine s7,and the overall lengh of stylet was more than twice of G.stokesi.Therefore,the diagnostic characteristic of the new species was quite clear.