Schindler Daniel E, Johnson Brett M, MacKay Neil A, Bouwes Nicolaas, Kitchell James F
Center for Limnology, University of Wisconsin, 680 North Park Street, 53706, Madison, WI, USA.
Oecologia. 1994 Feb;97(1):49-61. doi: 10.1007/BF00317908.
We studied size-structured predator-prey interactions between blue crabs (Callinectes sapidus) and marsh periwinkles (Littoraria irrorata) with a combination of field studies, laboratory experiments and individual-based modeling. Size distributions of Littoraria differed among years at the same sites in a salt marsh and could largely be explained by dominance of strong cohorts in the population. At a given site, abundance increased with elevation above tidal datum. Size-selective predation by blue crabs does not appear to be an important regulator of snail size distributions but may have a major effect on local abundance. Laboratory studies indicated that predator-prey interactions between Callinectes and Littoraria are strongly size-dependent. Crabs were generally effective at feeding on periwinkles at size ratios greater than approximately 6 (crab width: snail length). At lower size ratios crabs were far less effective at manipulating the snails, which often survived but with damaged shells. An individual-based model which incorporated information about incidence of snail shell scarring (resulting from non-lethal interactions) and snail density, predicted reduced predation rates and smaller average crab size with distance from the low tide refugium for crabs.
我们通过野外研究、实验室实验和基于个体的建模相结合的方法，研究了蓝蟹（Callinectes sapidus）和滨海滨螺（Littoraria irrorata）之间大小结构的捕食者 - 猎物相互作用。在盐沼的同一地点，滨海滨螺的大小分布在不同年份有所不同，这在很大程度上可以用种群中优势群体的主导作用来解释。在给定地点，丰度随着高于潮汐基准面的海拔升高而增加。蓝蟹的大小选择性捕食似乎不是蜗牛大小分布的重要调节因素，但可能对局部丰度有重大影响。实验室研究表明，Callinectes和Littoraria之间的捕食者 - 猎物相互作用强烈依赖于大小。当大小比大于约6（蟹宽：蜗牛长）时，螃蟹通常能有效地捕食滨螺。在较低的大小比下，螃蟹操纵蜗牛的效率要低得多，蜗牛通常能存活下来，但壳会受损。一个基于个体的模型结合了蜗牛壳疤痕发生率（由非致命相互作用导致）和蜗牛密度的信息，预测随着螃蟹离低潮避难所距离的增加，捕食率会降低，螃蟹的平均大小也会变小。
