北戴河潮间带现代介形虫的分布

由北戴河潮间带的12个样品分析得到介形虫29属46种。由于具体的小生境,缺少淡水介形虫, 北戴河潮间带底栖动物丰富,介形虫组合的主要特征与胶州湾东北角小海湾及东、黄海潮间带和潮下带介形虫的组合相似。在风化、潮汐和波浪等作用下,潮间带介形虫的壳体表面受机械磨蚀和破坏保存不好,充分反映出其异地埋藏特点。 通过研究北戴河潮间带介形虫,为研究我国辽阔沿海地区潮间带和潮下带介形虫的组合特征、分布范围及地理分区提供了很有价值的资料,并对海洋地质学、古生态学及沉积相等的研究具有重要意义。

DISTRIBUTION OF RECENT OSTRACODA IN THE LITTORAL ZONE OF BEIDAIHE, HEBEI PROVINCE

The material studied in this paper was collected from the littoral zone in the offshore area of Beidaihe situated in the southwest part of Qinhuangdao City (see Fig.1). Totally 46 species of 29 genera of Ostracoda from 12 samples are identified and quantitatively studied (see Table 1). As controlled by the environmental factors of different niches in the littoral zone all of them are marine forms and no freshwater taxa has been found. 1. Benthic faunas, especially infaunas are rich in the littoral zone. In addition to abundant foraminiferas and Ostracods, there are also some Anomia, Donax and Umbonium thonasi and so on in Sandy samples. 2. In ostracod taphocoenosis of the littoral zone the most dominant genera of Ostracoda are Sinocytheridea, Bicornucythere, Cushmanidea, Neomonoce-ratina, Loxoconcha, Pistocythereis, Campylocythereis and Aurila (see Table 1). 3. Principal features of the ostracod assemblage in the littoral zone off the Beidaihe coast bear resemblance in most aspects to those of ostracod assemblages of the small bay of northeastern Jiaozhou Bay and the littoral and sublittoral zones in the East China Sea and the Yellow Sea (see Table 2). 4. The ostracod carapaces are of poor preservation in the littoral zone, they are fragmentized or being abrased under effects of weathering, erosion as well as of tide and wave action. The fact gives fullest illustration that they were not buried in situ representing an extraneous taphocoenosis. 5. Results obtained by studying the littoral Ostracodes in the offshore area of Beidaihe, provide valuable data for the study of characteristics, distribution and geographical demarcation of littoral and sublittoral ostracod assemblages along the long extending coast of our country, and are also significant for the study of marine geology, palaeoccology and sedimentary facies in littoral and sublitto ral zones.