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.
Origin	Under Construction.
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. Native organism(s) affected: Shell species of hosts or competitors.
Regulation in Japan	No action for prevention, mitigation, control, or eradication.
Introduced range in other countries	Unknown.

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.