Barker J S F
Department of Animal Husbandry, University of Sydney, 2006, Sydney, N.S.W., Australia.
Oecologia. 1971 Jun;8(2):139-156. doi: 10.1007/BF00345810.
In interspecific competition studies, some cases of apparent change in competitive ability have been reported. But the change in competitive outcome could equally well be due to character displacement. As a preliminary to studies of the effects of association of D. melanogaster (yellow white mutant strain) and D. simulans (vermilion mutant strain), the nature and extent of ecological differences between them, and the nature of their competitive interaction was studied. Differences between the strains were shown for oviposition site preferences, and for larval and pupal distribution. In pure species cultures, simulans showed a greater preference than melanogaster for oviposition in the center of the medium surface. In mixed populations, simulans had an increased preference for this oviposition site, where melanogaster was at low frequency. D. simulans larvae utilized the lower half of the medium to a significantly greater extent than did melanogaster. At low density (5 pairs of parents) in pure species cultures, 68.7% of simulans pupae were on the medium surface. As parental numbers increased, this proportion decreased. The distribution of melanogaster pupae was quite different, with only 8 to 12% on the medium at all densities. But the remaining pupae tended to occur higher on the cylinder wall as parental numbers increased. The competitive interaction changed during the developmental period. At four and eight days after culture initiation, simulans appeared superior, while for total adult progeny production, melanogaster was slightly superior. These strans of the two species were not ecologically equivalent.
在种间竞争研究中，已经报道了一些竞争能力明显变化的案例。但竞争结果的变化同样可能是由于特征取代。作为研究黑腹果蝇（黄白色突变株）和拟果蝇（朱红色突变株）关联效应、它们之间生态差异的性质和程度以及它们竞争相互作用性质的初步研究，对这些进行了研究。结果表明，这两个菌株在产卵位点偏好以及幼虫和蛹的分布方面存在差异。在纯种培养中，拟果蝇比黑腹果蝇更倾向于在培养基表面中央产卵。在混合种群中，拟果蝇对这个产卵位点的偏好增加，而黑腹果蝇在该位点的频率较低。拟果蝇幼虫利用培养基下半部分的程度明显高于黑腹果蝇。在纯种培养中低密度（5对亲本）时，68.7%的拟果蝇蛹在培养基表面。随着亲本数量增加，这一比例下降。黑腹果蝇蛹的分布则大不相同，在所有密度下，只有8%至12%的蛹在培养基上。但随着亲本数量增加，其余的蛹倾向于出现在圆筒壁更高的位置。竞争相互作用在发育期间发生了变化。培养开始后四天和八天时，拟果蝇似乎更具优势，而对于成虫后代的总产量，黑腹果蝇略占优势。这两个物种的这些菌株在生态上并不等同。
