【摘要】 1957年5—7月在川西阿坝藏族自治州马尔康附近卓克基的纳足沟采得一批长尾岩栖亚属(Maxomy Sody)的鼠类,从形态、生态及内部繁殖器官等方面进行研究,发现虽然它们外形和毛色及一般形态特征十分相似,极易混淆,但还可以从一些新发现的指标来确定 其一为社鼠(Rattus niviventer Hodgson,1836),另一种为白腹鼠(Rattus coxingi Swinhoe,1864)。 经生物学特性对比,发现它们栖息习性不同,社鼠多栖于桦树林及桦栎混交林中,白腹鼠多栖于高山栎林及人房中。在年龄组成上也有显著性差异,白腹鼠繁殖季节开始比较早。在体外寄生螨相方面也有显著性差异,社鼠带有土耳其斯坦恐螨(Laelaps turkes-tanicus Lange,1955)的个体占76.2%,而白腹鼠带有这种螨的个体只有19.4%; 白腹鼠带有刺恐螨(Laelaps echidininus Berlese,1887)的个体占66.7%,而社鼠只有6.4%。 在形态方面,经过细致的对比,发现虽大同,却仍有小异。如后足长、颧宽、后头宽、上齿列长、M~1宽、M~2宽和M~3长,社鼠均小于白腹鼠。最重要的是在性成熟时期两种鼠类睾丸长有显著的差异,社鼠睾丸长为18.2±0.13毫米(17.2—20.0毫米),而白腹鼠为12.3±0.31毫米(10.0—15.0毫米),二者平均值有显著差异,分布范围也没有重迭。 这两种鼠类同域分布,形态虽大同,却仍有小异,?更多还原

【Abstract】 Rattus niviventer Hodgson is morphologically very similar to Rattus coxingi Swinhoe and they occur sympatrically in Szechwan. According to Thomas (1911) and Allen (1940), the two rats differ in body size and length of tail as well as in the color of the abdomen. But these characters show considerable overlaps, and the similarities of the two species are so great that specimens of either species may easily be misidentified.Based on our field observation, we found that the two species differ in habitats and breeding season as well as in their external parasitic mites. The habitat of Rattus niviventer is chiefly in the birch forest or birch and oak mixed forest, whereas that of Rattus coxingi principally in the oak forest or human dwellings. The breeding season of the Rattus coxingi occurs earlier than that of Rattus niviventer. The external parasitic mites of the two rats also differ. 76% of Rattus niviventer specimens are found to be infected with Laelaps turkestankus Lange, whereas only 19% of Rattus coxingi specimens are infected with the same exoparasite. On the other hand, 67% of Rattus coxingi specimens are infected with Laelaps echidininus Berlese, as against only 6% of Rattus niviventer. Morphologically, we have found differences in the average measurements of hind foot, zygomatic breadth, mastoid breadth, upper tooth row, widths of M1 & M2 and the length of M3.Lastly, the two rats differ most obviously in the size of their testes, the length of the testes averaging 18.2±0.13 (17.2-20) mm in Rattus niviventer, and only 12.3±0.31 (10-15) mm in Rattus coxingi, when they are sexually mature.更多还原