【摘要】 <正> 一、前言 鄱阳湖位于长江中游,江西省的北部,面积约为3,350平方公里,是我国最大的淡水湖泊。湖的东北部有乐安江,东南部有信江,南部有赣江及旴江,西部有修水和博阳河等注入湖中。湖在北部的湖口处与长江相通。湖水的深度有显著的季节变化,一般在6—7月水位最高,水深约3—8米,11—2月水位最低,水深约1—3米。常水期间,湖口附近水位较长江为高,湖水由此排入长江,仅在湖的枯水期或长江特大洪水时,才接纳一部分长江水量。因此,它对长江水量的调节不及洞庭湖大,它的淤塞也较洞庭湖慢。该湖及其附更多还原

【Abstract】 Poyang Lake, the greatest fresh-water lake of China today, is located in the northern part of Kiangsi Province, communicating with the Yangtsekiang at its middle reach, covering an area about 3350 sq kms. It receives the water chiefly from the Loankiang (乐安江)Sinkiang (信江), Fu Ho (抚河), Kankiang (赣江), Suishui (修水) and Pohyang Ho (博阳河) fr癿 east, south and west and flows into the Yantsekiang at Hukow (湖口) in the northern part of the lake. Specimens were collected from the different regions of the lake and its surrounding waters in April, 1963. 47 species, belonging to three families (Mytilidae, Unionidae, Corbiculidae) and sixteen genera, were determined. Among them, one species is found to be new to science.The characteristics of the bivalve fauna of Poyang Lake were carefully analyzed and a comparison of the bivalve fauna of Poyang Lake with that of Tung Ting Lake was made. The species inhabiting these two lakes are found to be fundamentally similar, but the species distributed in Poyang Lake are more uniform than those in Tung Ting Lake.Description of the new species is given below:Cuneopsis kiangsiensis, sp. nov.Localities: in Fu Ho, Siehfow (谢埠); in Sinkiang, Juihung (瑞洪); Poyang(鄱阳).Shell large, cuneiform, thick and solid, subinflate; right and left valves unequal in height, right one obviously projected upwards near by the ligament, and the projection being higher than the corresponding part of the left one; beaks placed at the anterior end of dorsal edge, always eroded; anterior ends of the valves rounded and much higher than the posterior; dorsal edge almost straight; base line arched or slightly arched, epidermis polished, brown-chestnut; growth lines fine, not shined. Left valve with two elongated laterals and two pseudocardinals, the posterior one of the latter well developed, obliquely triangulate; right valve with one strong and rough pseudocardinal and one elongated lateral. Length of the laterals of both the left and the right valves subequal to the height of the shell. Anterior muscle scar deep, funnel-shaped; posterior muscle scar obvious, elliptical in shape. Beak cavity moderatly deep; nacre ashy-white or salmon.Holotype: Length 124mm, height 56mm, diameter 39mm; locality: in Sinkiang, Juihung, collected on April 5, 1963, by Li Shih-Cheng.Paratype: Length 119mm, height 51mm, diameter 35mm; locality: in Sinkiang, Juihung, collected on April 5, 1963.Holotype and paratype preserved in the Institute of Zoology, Academia Sinica, Peking.Remarks: This new species closely resembles Cuneopsis celtiformis (Heude, 1874), but differs from the latter by the characters, as shown in the following table:更多还原