EFFECT OF IN TRODUCED SPECIES ON BIOLOGICAL DIVERSITY : A SYNTHETIC STUDY ON A HYBRID POPOULATION OF TAIWANESE MACAQUES IN WAKAYAMA

和歌山的台湾猕猴和日本短尾猴的年增长率很高(14%)。在研究期间，它们从两组增加到四组，分布区域几乎没有扩大。它们表现出较少的杂交崩溃症状，似乎对环境条件适应得很好，这表明它们对本地生态系统有潜在的不利影响。相对尾长与尾椎数量呈显著正相关，尾部形态是每个个体杂交程度的良好指标。通过田间观察尾部形态，可以对杂交种进行鉴定。在时间距离、门牙大小和磨牙大小上存在物种差异。在牙齿的相对大小差异方面，与亲本物种的变异范围相比，一些杂交种表现出非加性特征。群体遗传学研究表明，组成…的变化较小在研究期间，更多的外来基因或不同程度杂交的杂交种比例。Fuscata基因和杂交个体在种群中的比例估计分别约为50%和90%。根据遗传标记的分布，认为外来雄性日本猕猴的基因流动是其杂交的触发因素。两个物种的随机交配得到了两个遗传标记的支持，但另外两个标记表明纯合子个体过多，这表明杂交群体可能发生了一些选择性变化。在监测雄性迁徙的杂交种群扩张过程中，建立了一种新的Y染色体分型方法，并结合染色体上的多态微卫星DNA基因座进行了有效的应用。显微镜观察发现，杂交个体的精子发生正常，表明两个猕猴物种之间的合子后生殖隔离机制发展较少。在野外对感染病毒的检测发现，杂交种群与本地物种没有差异。对于血液寄生虫，本研究未发现疟原虫和丝虫。对粪便样本的检测发现了日本猕猴中常见的两种线虫卵。最后，本研究结果展示了杂交种群中各种生物学性状的新发现，并推断了猕猴物种形成中生殖隔离的发展，以及引进外来猕猴物种对保护管理的潜在影响的重要信息。较少

The hybrids between Taiwanese (Macaca cyclopis) and Japanese (M. fuscata) macaques in Wakayama showed high annual growth rate (14 percent). They increased from two to four groups with little expansion of distribution areas during the study period. They showed less symptom of hybrid breakdown and seemed to adapt well to the environmental conditions, suggesting potential adverse effects on native ecosystems.Relative tail length and the number of caudal vertebrae showed significantly positive correlation and the tail morphology was a good indicator of the degree of hybridization for each individual. It was proved that observation of tail morphology in field could allow us to evaluate hybrids. Species differences were found in the inter-temporal distance, and the sizes of incisors and molars. In the relative size differences in teeth, some of hybrids showed non-additive profile compared to the variation ranges in parental species.Population genetic study revealed less changes in the compos … More ition of exotic genes or proportion of hybrids with various degrees of hybridization through the study periods. The proportions of fuscata genes and hybrid individuals in the population were estimated to be approximately 50 percent and 90 percent, respectively. Based on the distribution of genetic markers, the trigger of hybridization was considered to be gene flow by males of Japanese macaques came from outside areas. Random mating of two species was supported by two genetic markers, but two other markers suggested excess of homozygous individuals, suggesting a possibility of some selective changes in the hybrid population. In monitoring expansion of the hybrid population by male migration, a new method of Y chromosome typing was established and used effectively by combining polymorphic microsatellite DNA loci on the chromosome.Microscopic observations found normal spermatogenesis in hybrid individuals, indicating less development of postzygotic reproductive isolation mechanism between the two macaque species.Inspection of infectious viruses detected no difference between the hybrid population and native species in wild. For blood parasites, no worms of Plasmodium and Filaria were observed in this study. Inspection of fecal samples detected two kinds of eggs of nematodes commonly known in Japanese macaques.Finally, the results of this study presented new findings of various biological traits in the hybrid population and inference on the development of reproductive isolation in macaque speciation as well as important information on potential impact of introduced foreign macaque species for conservation management. Less