, Volume 305, Issue 1, pp 55–61

Taxonomy and geographical distribution of Dugesia japonica and D. ryukyuensis in the Far East

  • Masaharu Kawakatsu
  • Iwashiro Oki
  • Sachiko Tamura
Biogeography and genetics

DOI: 10.1007/BF00036363

Cite this article as:
Kawakatsu, M., Oki, I. & Tamura, S. Hydrobiologia (1995) 305: 55. doi:10.1007/BF00036363


Dugesia japonica Ichikawa et Kawakatsu, 1964, is a common and polymorphic species of freshwater planarian distributed widely in the Far East. In 1976 the geographic populations were separated into 2 subspecies (D.j.japonica and D.j. ryukyuensis). The taxonomy of this species is reconsidered once again from the morphological, anatomical, histological, and karyological viewpoints. From the result of these studies, D.j. ryukyuensis is elevated to the rank of species: D. ryukyuensis Kawakatsu, 1976. D. japonica (n = 8, 2x = 16, 3x = 24) differs from D. ryukyuensis (n = 7, 2x = 14, 3x = 21) in having an asymmetrical penis papilla without a well-developed valve surrounding its basal part, and a well-developed vagina (distribution: the Japanese Islands, Taiwan, the Korean Peninsula, China, and Primorskiy, Northeast Siberia, in Russia). D. ryukyuensis is characterized by an asymmetrical penis papilla with a well-developed valve surrounding its basal part, and a less-developed vagina (distribution: the Southwest Islands of Japan).

Key words

Turbellaria Tricladida Dugesia taxonomy Japan Far East 

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • Masaharu Kawakatsu
    • 1
  • Iwashiro Oki
    • 2
  • Sachiko Tamura
    • 3
  1. 1.Biological LaboratoryFuji Women's CollegeSapporo (Hokkaidô)Japan
  2. 2.Ôsaka Environmental Project AssociationChû'ô-ku, ÔsakaJapan
  3. 3.Ôsaka Prefectural Institute of Public HealthHigashinari, ÔsakaJapan

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