摘要
双壳动物形态变化是适应环境变化的一个重要方面。但不同环境条件下的适应机制可能存在差异。河蚬是一种底栖双壳类动物,原产东南亚,现分布于世界许多地区。本研究采集了我国江、淮、黄河和西江等主要流域的河蚬样品,进行了三度空间尺度分析,以认识壳体形态的区域变化及其影响因素。结果表明,长江上游和西江上游等高山与峡谷地区河蚬的相对高度、圆度和凸度均小于黄淮、汉水流域和西江中下游等低山和平原地区。水流速度是造成这种形态适应性变化的主要原因。流速的增加使河蚬向相对长、矮和扁的方向发展,这种形态利于个体在底质中固定下来而不被水流冲走;而缓慢的水流使河蚬向相对宽圆的方向发展。环境温度、水体化学与河蚬形态之间不存在相关性,表明二者对河蚬形态的影响不明显。上述结果不仅有助于认识双壳动物对环境变化的适应性,而且对我国的河蚬养殖和捕捞也具有指导意义。
The morphological change of bivalve mollusk is believed to be an adaptation to environmental change,but the adaptation mechanism under different environmental conditions may differ.Corbicula fluminea（Müller,1774） is a benthic bivalve native to South and East Asia and a dominant invasive species in many aquatic environments globally.In this paper,specimens of C.fluminea were collected along a transect crossing the major watersheds of China,including the Yellow,Huaihe,Hanshui,Yangtze,and Xijiang Rivers,with the morphometry studied,aimed to understand the regional change of C.fluminea shell morphology and its affecting factors.In the upstream tributaries of the Yangtze and Xijiang Rivers,which were located in the mountainous regions of western China,the C.fluminea shell was relatively long,low,and thin;while in the lower reaches of Yellow river,upstream tributaries of Huai River and Hanshui River,and middle and lower reaches of Xijiang River,which were located in the hilly areas or plains in the south and east China,the shell was relatively short,high,and thick.These changes revealed the adaptation of the clam to the changes of water current rate.The large contrast of topography created high flow rate in mountainous regions,where the clam evolved to become longer,lower,and thinner so as to resist the involuntary displacement by high flow rate water current;while the slow flow rate in the plains or low mountain areas encouraged the shell morphology to become relatively short and round.The changes of water temperature and water chemistry（mainly Ca^2＋ and K^＋ concentrations） had little effects on the shell morphometry.These results not only provided insight into the adaptation mechanism of clams to environmental change,but also helped guiding the cultural practices of C.fluminea in China.
出处
《生态学杂志》
CAS
CSCD
北大核心
2011年第7期1497-1503,共7页
Chinese Journal of Ecology
基金
国家自然科学基金项目(40403010
40721002)资助
关键词
软体动物
双壳类
经济贝类
形态变化
水流速度
生物适应性
mollusc
bivalve
economic shellfish
morphologic allometry
water current
biological adaptation
