New records and distributions of two North American branchiobdellidan species (Annelida: Clitellata) from introduced signal crayfish, Pacifastacus leniusculus, in Japan

Akifumi Ohtaka, Stuart R. Gelder, Tadashi Kawai, Kazuhiro Saito, Kazuyoshi Nakata, Machiko Nishino

Research output: Contribution to journalArticle

29 Citations (Scopus)


This is the first report of two North American branchiobdellidans, Sathodrilus attenuatus Holt, 1981, and Xironogiton victoriensis Gelder and Hall, 1990, on the signal crayfish, Pacifastacus leniusculus (Dana, 1852) introduced into Japan from the Columbia River system, northwestern North America. Signal crayfish from 12 localities in eastern and northern Hokkaido, Japan, were examined and each supported S. attenuatus. In addition, an individual of this species was found on preserved material from Ishikawa Prefecture, central Honshu. All of these branchiobdellidans reported in Hokkaido most probably came from the original population of signal crayfish introduced into Lake Mashu, Hokkaido, Japan, in 1930. It is suggested that the use of non-pathogenic branchiobdellidans, when present, provides an easy method for tracing the spread of crayfishes around Japan and could also be applied in other countries and continents. Specimens of X. victoriensis were only found on crayfish in a stream at Akashina in Nagano Prefecture, central Honshu, Japan. Although the signal crayfish appears to be displacing the endemic Japanese crayfish, C. japonicus, no native branchiobdellidans were found on any of the introduced signal crayfish examined.

Original languageEnglish
Pages (from-to)149-156
Number of pages8
JournalBiological Invasions
Issue number2
Publication statusPublished - Mar 2005
Externally publishedYes



  • Branchiobdellida
  • Ectosymbionts
  • Introduced species
  • Japan
  • Pacifastacus leniusculus
  • Sathodrilus attenuatus
  • Xironogiton victoriensis

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Plant Science
  • Ecology, Evolution, Behavior and Systematics

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