PDF(Pubmed)
Abstract：
Substantial research exists on predation and its ecology. Most research has focused on durophagous fishes, brachyuran crabs, and lobsters. Data are lacking, however, on soft-bodied predators like anemones, and their contribution to overall levels of predation remains largely unevaluated. Here, we compared predation rates of the durophagous predator, the crab C. maenas and the soft-bodied predator, the anemone Actinia equina on 15 intertidal shores around Anglesey, north Wales, UK. We employed a novel approach to assess predation based on measuring faecal output from recently collected individuals and converting it to food consumed using absorption efficiencies (AEs) measured using potential prey species inhabiting the same shores. Anemone mean abundance was 8.21 (± 0.27, s.e.) individuals.m-2, whereas for C. maenas it was 0.23 (± 0.02, s.e.) individuals.m-2. AEs when fed mussel tissue, a polychaete worm, or a shrimp were 92.8-94.0% in C. maenas and 40.5-95.8% in A. equina. This difference in values reflected the different feeding modes of the two predators. Unexpectedly, A. equina consumed 3.5-7 times more prey than C. maenas. The consumption of larger amounts of prey by an anemone than the dominant durophagous predator has important consequences for calculating energy flows in food webs, understanding predation controls in assemblages, and potentially for wider predation trends.
摘要：
关于捕食及其生态学的大量研究。大多数研究都集中在双食鱼类上，短尾草蟹,和龙虾。缺乏数据，然而,在像海葵这样的软体动物身上，它们对总体捕食水平的贡献仍未得到评估。这里,我们比较了双食捕食者的捕食率，螃蟹C.maenas和软体动物，安格尔西周围15个潮间带海岸的海葵马术，北威尔士,英国。我们采用了一种新颖的方法来评估捕食，该方法基于测量最近收集的个体的粪便输出，并使用使用居住在同一海岸的潜在猎物物种测量的吸收效率（AE）将其转换为消耗的食物。海葵平均丰度为8.21(±0.27,s.e.)个体。m-2，而C.maenas为0.23（±0.02，s.e.）个体。m-2.饲喂贻贝组织时的AE，多毛蠕虫,或虾在C.maenas中占92.8-94.0％，在马匹中占40.5-95.8％。这种数值的差异反映了两种捕食者的不同喂养方式。出乎意料的是,马匹消耗的猎物是C.maenas的3.5-7倍。海葵比主要的双食性捕食者消耗更多的猎物，对计算食物网中的能量流具有重要的影响。了解集合中的捕食控制，并可能导致更广泛的捕食趋势。
