Interspecific interactions by allelopathy and predation in land snails.

利用生长减速和捕食作用，在实验种群中进行了种间相互作用的实验研究。结果表明，无论是捕食还是生长减速，相似拟青虫都明显占优势。其次，相似双胞菌的优势被检测为其促进生长和减少同类相食的积极收益。干扰引起的种间互作被认为是对隐性物种的负面影响。因此，这一结果提供了一个干扰相互作用的例子，分别对显性和隐性物种造成了积极和消极的影响。在目前的条件下，密度对种内竞争生长的影响不显著，而相似拟青虫的生长与密度呈负相关。由于这一反差，在相同的总密度下，当所有动物都是相似拟青虫时，对相似拟青虫的总密度效应要低于与拟青霉共生时的总密度效应。个体固有生长率与受生长干扰的程度呈正相关。生长缓慢的幼鱼没有明显的生长减退现象，而快速生长的幼体受到明显的干扰作用。这两个物种的组成和相对频率对捕食率和生长干扰没有明显的影响。

Interspecific inerference by growth reduction and predation was tested in experimental populations of Bradybaena similaris and Acusta despecta. As the results, B.similaris was clearly dominant in both predation and growth reduction. Second, the dominance of B.similaris was detected as its positive gains of increased growth and reduced cannibalism. The interspecific interactions by interference have been understood as negative effects against the recessive species. Thus, this result provides an example of interference interactions which causes both positive and negative effects for the dominant and recessive species, respectively. Densiyt effects on growth (intraspecific competition) were not statistically significant in A.despecta in the present conditions, whereas the growth of B.similaris was negatively correlated with density. Because of this contrast, the total density effect for B.similaris is lower when it lives with A.despecta than when all animals are B.similaris in the same total density. There were positive correlations between the individual inherent growth rate and the degree of growth interference A.despecta suffers. There was no detectable growth reduction in juveniles of slow growth, while the interference effect was significant in groups of fast growth. There was no detectable effect of composition and relative frequencies of the two species on the predation rate or growth interference.