杰氏涡虫属一新种(扁形动物门,单肠目,达氏科)

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

报道单肠目达氏科杰氏涡虫属1新种,武夷山杰氏涡虫Gieysztoria wuyishanensis Wang et Lai,sp.nov.,隶属于杰氏涡虫属异刺群钩刺亚群,该亚群涡虫在中国属首次报道。标本由张宇于2005年5月6日采自福建省南平市武夷山九曲溪(27°45'N,118°1'E)的溪边水草间,水温18℃,pH7.8。详细描述了新种形态特征,所有标本保存于中国科学院动物研究所。

A new species, Gieysztoria wuyishanensis Wang et Lai sp. nov., of the genus Gieysztoria （Platyhelminthes, Rhabdocoela, Dalyelliidae） was described in this paper. Material. Holotype, PLA-G0001, Jiuqu Stream （27°44′N, 118°1′E）, Mt. Wuyi, Nanping City, Fujian Province, China, May 2005. Paratypes, PLA-G0002; the same date and locality as holotype. All the type specimens were collected by ZHANG Yu （the teacher in College of Life Science, Shenzhen University） and deposited in National Zoological Museum, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road, Chaoyang District, Beijing 100101, 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 Inaequalesof 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℃; pH 7.8. Etymology. The species was named after the locality Mt. Wuyi where the type specimens were collected; adjective. Remarks. Gieysztoria wuiyishanensis sp. nov., a speciesbelonging 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. stokes （2012） comparing the stylet morphology. However, there were still some differentia. The stylet of G. stokes was 115 μm long with 4 spines （s1, s2, s3 and s6）, while the stylet of G. wuiyishanensis sp. nov. was 240 μm 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. stokes, G. wuiyishanensis sp. nov. had 1 more spine s7, and the overall lengh of stylet was more than twice of G. stokes’. Therefore, the diagnostic characteristic of the new species was quite clear.