Horizontal distribution of large tintinnids in Yangtze River
长江口2005年4个航次中大型砂壳纤毛虫的水平分布

Species composition and abundance of large tintinnids (>76 μm) in the Yangtze River estuary were studied in four seasonal cruises in 2005. Samples were taken by vertically towing a Shallow Water III plankton net from bottom to surface. Totally 11 tintinnid species were found: Codonellopsis ostenfeldi, C. parva, Eutintinnus tenuis , Favella panamensis , Leprotintinnus nordqvisti , Leprotintinnus sp., Tintinnopsis japonica, T. karajacensis,T. mortensenii, T. radix, and T. schotti. Maximum abundance of Leprotintinnus sp. was 32400 ind./m3 while maximum abundance of some species was lower than 200 ind./m3 (C. parva, E. tenuis and T. mortenseniO, And T.japonica mainly distributed in the area out of Yangtze River mouth in winter. Leprotintinnus sp. occurred in the area out of Yangtze River mouth in spring, summer and autumn. No tintinnid was found inside the Yangtze River in the four cruises.