Interspecific interactions by allelopathy and predation in land snails.

在实验种群中，测定了生长抑制和捕食引起的种间干扰。结果表明，相似小蠊在捕食和生长抑制方面均具有明显的优势。其次，相似b .的优势表现为其增加生长和减少同类相食的积极收益。由干扰引起的种间相互作用被理解为对隐性种的负面影响。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产生积极和消极的影响。密度对种内竞争的影响在本实验条件下无统计学意义，而相似小蠊的生长与密度呈负相关。由于这种对比，当相似白僵虫与斑拟虫生活在一起时，其总密度效应比所有动物都是相同总密度的相似白僵虫时要低。个体固有生长率与生长受干扰程度呈正相关。生长速度慢的幼鱼没有明显的生长减少，而生长速度快的幼鱼的干扰效应显著。两种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.