Morphological variation and geographical and altitudinal distribution in Eothenomys melanogaster and E. mucronatus Rodentia, Arvicolinae)in China, Taiwan, Burma, india, Thailand, and Vietnam

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Abstract

I classified about 600 museum specimens of Père David's vole and examined its distribution. In a restricted area of Burma (25.70-26.13°N, 98.13-98.70°E; Myanmar, Area V), 150 individual specimens sampled during the same period could be classified into two groups on the basis of the relationship between the hind foot length (HFL) and tail length (TL): the large (L) and small (S) types. Group L was distributed at altitudes above 2460 m, whereas Group S was found below 2460 m. The distance between the incisor and third upper molar (I-M3) exceeded 14.3 mm in Group L, and was less than 15.2 mm in Group S. Except for young individuals, specimens from Groups L and S from Area V differed in two external and 14 cranial measurements. The molar pattern of the third upper molar ranged from simple to complex types, and varied both within and between Groups L (Types B, C, and D) and S (Types B and C), indicating that it is inadequate as a primary diagnostic character. The relationship between TL and HFL differentiated the groups in Areas III, IV (Yunnan Province, China), VI (India, Thailand, Vietnam, and northern Burma), and VII (the provinces of Zhejiang and Fujian in China, and Taiwan), but did not differentiate them in Areas I (the provinces of Hubei and Guizhou) or II (the provinces of Gansu and Sichuan), where histograms of I-M3 distinguished Groups L and S. Proportional likeness was represented using a ratio diagram; the lines for 11 cranial dimensions distinguished Group L from Group S, indicating that they are two distinct species. Group L was identified as Eothenomys mucronatus (Allen, 1912); it was distributed in Areas II, III, V, and VI. Group S was identified as E. melanogaster (Milne-Edwards, 1872); it was distributed in Areas I, II, IV, V, and VII. The elevations at which E. melanogaster occurred decreased from southwest to northeast, whereas no clear altitudinal tendency was seen in E. mucronatus.

I classified about 600 museum specimens of Père David’s vole and examined its distribution. In a restricted area of Burma (25.70-26.13°N, 98.13-98.70°E; Myanmar, Area V), 150 individual specimens sampled during the same period could be classified into two groups on the basis of the relationship between the hind foot length (HFL) and tail length (TL): the large (L) and small (S) types. Group L was distributed at altitudes above 2460 m, whereas Group S was found below 2460 m. The distance between the incisor and third upper molar (I-M3) exceeded 14.3 mm in Group L, and was less than 15.2 mm in Group S. Except for young individuals, specimens from Groups L and S from Area V differed in two external and 14 cranial measurements. The molar pattern of the third upper molar ranged from simple to complex types, and varied both within and between Groups L (Types B, C, and D) and S (Types B and C), indicating that it is inadequate as a primary diagnostic character. The relationship between TL and HFL differentiated the groups in Areas III, IV (Yunnan Province, China), VI (India, Thailand, Vietnam, and northern Burma), and VII (the provinces of Zhejiang and Fujian in China, and Taiwan), but did not differentiate them in Areas I (the provinces of Hubei and Guizhou) or II (the provinces of Gansu and Sichuan), where histograms of I-M3 distinguished Groups L and S. Proportional likeness was represented using a ratio diagram; the lines for 11 cranial dimensions distinguished Group L from Group S, indicating that they are two distinct species. Group L was identified as Eothenomys mucronatus (Allen, 1912); it was distributed in Areas II, III, V, and VI. Group S was identified as E. melanogaster (Milne-Edwards, 1872); it was distributed in Areas I, II, IV, V, and VII. The elevations at which E. melanogaster occurred decreased from southwest to northeast, whereas no clear altitudinal tendency was seen in E. mucronatus.

Journal

  • Mammal Study

    Mammal Study 27(1), 31-63, 2002-06-01

    Mammalogical Society of Japan

References:  90

Cited by:  3

Codes

  • NII Article ID (NAID)
    10008710269
  • NII NACSIS-CAT ID (NCID)
    AA11185060
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    1343-4152
  • NDL Article ID
    6263927
  • NDL Source Classification
    ZR4(科学技術--生物学--動物)
  • NDL Call No.
    Z54-G149
  • Data Source
    CJP  CJPref  NDL  IR  J-STAGE 
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