黄海小型砂间多毛类异触虫属一新种

A NEW INTERSTITIAL SPECIES OF THE GENUS PISIONE (POLYCHAETA: PISIONIDAE) FROM YELLOW SEA, CHINA

于1987年11月在青岛附近的脱岛采到属于异触虫科的小型砂间多毛类数条。经研究表明,这些标本为异触虫属的新种——滑毛异触虫Pisione livisetosa。本文对该新种进行了详细的描述并附有形态图。新种模式标本保存于国家海洋局第一海洋研究所。

Almost all pisionid species belong to meiofauna and live in interstices of sandy sediment. Until now Pisionidae has not been reported from China. In a study of polychaete meiofauna from Yellow Sea, an undescribed species of the genus Pisione was found in the littoral area of a small island near Qingdao (35°56'27'N, 120°19'47'E; 35°56'11'N, 120°19'15'E) in 1987. Both holotype and 4 paratypes have been deposited in the First Institute of Oceanography, State Oceanic Administration, Qingdao.Pisione levisetosa nov. sp. (Fig. 1,2)Complete specimen up to 8.5 mm long, with up to 48 chaetigers; width 0.25 mm without parapodia, 0.7 mm with parapodia. Palps very long (Fig. 1 a), 0.7-0.8 mm. Two pairs of tentacular cirri; articulation of dorsal ones unconspicious and about one seventh as long as the palps; ventral ones small and bi-articulated; their acicular spines distally enlarged with bluntly serrated asymmetrical distal margin (Fig. 2 a). One pair of eyes. Two pairs of jaws, Many pointed papillae scattered on palps and tentacular cirri. Uniramous parapodia with spherical flask-like dorsal and ventral cirri of same size and shape in all segments, except for the first chaetiger; here ventral cirri elongate and as long as the dorsal tentacular cirri (Fig. 1 b-c). Stiff sensory cilia on tips of dorsal and ventral cirri. Parapodial lobe with soli-tory positioned straight acicula and bundle of chaetae that usually consists of five distally projecting chaetae and one stout acicula. One supra-acicular simple chaeta stout, with oblique serrated apical part (Fig. 2 b). One sub-acicular pointed simple chaeta, with subdis'al transverse ridge on anterior parapodia (Fig. 2 d-e); this chaeta about two times longer in the posterior parapodia. Three sub-acicular compound chaetae: the superior-most blade with long pointed, possessing long, slender serrations (Fig. 2 c); the middle one with stout blade, the serrations of which more prominent (Fig.2 f-g); the inferio-most compound with stout, relatively short, smooth blade (Fig.2 h-i). Shafts of middle and inferio-most compound chaetae with subdistal transverse ridge, distally bifid. All compounds unidentate. Pygidium wi+h pointed papillae.Pisione levisetosa nov. sp. belongs to a group of species, which do not possess dorsal cirri* The project was supported by the National Natural Science Foundation of China and th?Ministry fc>r Research and Technology (BMFT), Bonn, FRO. of different size and shape on the second chaetiger. Among these P. gopalai (Alikunhi, 1941); P. koepkei Siewig, 1955; P. longipalpa Ushakov, 1956; P. reducta Storch, 1967; P. laubieri Hart-mann-Schroder, 1970; P. corallicola Hartmann-Schroder, 1974; P. martinsi' Hartmann-schro der, 1974; P. galapagoensis Westheide, 1974 are equiped with only one simple chaeta with in their parapodial lobes. P. remota (Southern, 1914) shows nearly identical simple chaetae of two types (Stecher 1960). Two types of sample were also described for P. puzae Siewig, 1953. However, P. levisetosa nov. sp. differs from these two species in possessing compound chaetae of different types with or without serration.