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  3. Crepidula onyx

Crepidula onyx

Basic information
Scientific name Crepidula onyx (No picture)
Common names onyx slippersnail
Higher taxon Calyptraeidae, Neotaenioglossa, Gastropoda, Mollusca
Natural range Coast of California to Panama
Habitat Coast of intertidal zone to 30m depth. Fouling on shells of other large molluscs and rocks of intertidal zone.
Invasion information
Range in Japan Coast of Hokkaido, Sendai Bay, Fukushima, Kanto, Tokai, Kii Peninsula, Seto Inland Sea, Oita, N Kyushu, Ariake Inland Sea. Range in Japan
Date The first record was in 1968 at Miura Peninsula. Established in Tokyo and Sagami Bay by 1972, from Fukushima Pref. to Ise Bay by 1976. The first record at Osaka was in 1977. In 1980s to 1990, spread in western Japan.
Route With ballast water or fouling on ship.
Impact This species seems to inhibit behavior of hosts shell by many individuals fouling, and competitive with some other shell species such as oyster. But the ecological impacts seems not so large.
Affected organism: Shell species of hosts or competitors.
Regulation in Japan
Introduced range in other countries
Reference Notes
  • Ecol Soc Japan (ed) (2002) Handbook of Alien Species in Japan. Chijin-Shokan. (in Jpn)
  • Iwasaki et al. (2004) Human-mediated introduction and dispersal of marine organisms in Japan: Results of a questionnaire survey by the committee for the preservation of the natural environment, the Japanese association of benthology. Japanese Journal of Benthology. 59:22-44
  • etc.