Invasion HistoryFirst Non-native North American Tidal Record: 1924
First Non-native West Coast Tidal Record: 1924
First Non-native East/Gulf Coast Tidal Record:
General Invasion History:
Reishia clavigera is reported to range from northern Japan (Sendai) to Singapore, Borneo, and the Philippines (Abe 1983; Huang 2001; Academy of Natural Sciences of Philadelphia 2014a & b), although some of the tropical records could be a similar species (e.g. R. jubilaea, Singapore). In 1924 and 1951, specimens of R. clavigera were found on newly transplanted Pacific Oysters (Crassostrea gigas) in Washington and British Columbia. There have been no later reports of the whelks in North American waters (Hanna 1966; Carlton 1979).
North American Invasion History:
Invasion History on the West Coast:
In 1924, Kincaid (1947, cited by Hanna 1966; Carlton 1979) collected specimens from newly planted Japanese oysters in Samish Bay, Washington (WA). He found two more of these snails on boxes of oysters about to be planted in Willapa Bay, WA (Kincaid 1947 cited by Hanna 1966; Carlton 1979). In 1951, 63 R. clavigera and their egg cases were removed from a 1948 planting of Japanese Oysters, in Ladysmith, British Columbia (Hanna 1966; Carlton 1979). This whelk is considered to be extirpated in British Columbia, with no further records (Gillespie 2007).
The shell of Reishia clavigera is heavy and dextrally coiled with a short spire, with 5-6 whorls, including a large body whorl. The shell is heavily sculptured with large, blunt knobs, prominent growth lines, and spiral grooves. The body whorl bears five rows of knobs. The interior of the lip of the aperture is scalloped and strongly grooved. The exterior of the shell is grey, brown, or black, with white or gray axial and spiral stripes. The tips of the knobs are usually white. Shells of mature animals range from 20-40 mm long (Abe 1983). This description is based on photographs on websites, e.g. Natural History Museum of Rotterdam (http://www.nmr-pics.nl/) and Gastropods.com (http://www.gastropods.com/0/Shell_1670.shtml).
Thais tumulosa (None, None)
Thais clavigera (None, None)
Purpura clavigera (Küster, 1860)
Potentially Misidentified Species
Tan and Sigurdsson (1990), a similar species distinguished by shell features, radula and penis.
Similar species, reported from Taiwan (Wu et al. 2003)
Similar species, reported from Taiwan (Wu et al. 2003)
Reishia clavigera (Asian Rock Shell) is a predatory snail of the intertidal and shallow subtidal rocky shores and oyster beds. Sexes are separate, and fertilization is internal. Adult snails (20-45 mm) form large breeding aggregations. Females lay masses of egg capsules on pebbles and boulders (Abe 1983). The eggs hatch into planktonic veligers, which settle.
In Taiwan, R. clavigera prefers intertidal areas, and has a higher temperature preference (36C) than two other intertidal Reishia species. This whelk is a predator,feeding on barnacles, chitons, gastropods, bivalves, and polychaetes (Wu et al. 2006).
barnacles, chitons, gastropods, bivalves, worms
Cronia margariticola (predatory snail)
|General Habitat||Oyster Reef||None|
|General Habitat||Marinas & Docks||None|
|Salinity Range||Polyhaline||18-30 PSU|
|Salinity Range||Euhaline||30-40 PSU|
|Tidal Range||Low Intertidal||None|
Tolerances and Life History Parameters
|Maximum Temperature (ºC)||36||Preferred temperature, experimental (Wu et al. 2006).|
|Minimum Length (mm)||20||Abe 1983|
|Maximum Length (mm)||45||Abe 1983|
|Broad Temperature Range||None||Cold temperate-Tropical|
|Broad Salinity Range||None||Polyhaline-Euhaline|
General ImpactsReishia clavigera was found on newly planted Japanese oysters (Crassostrea gigas) in Samish Bay, Washington and Ladysmith, British Columbia, but did not become established. No impacts have been reported (Carlton 1979; Gillespie 2007).
Regional Distribution Map
|Bioregion||Region Name||Year||Invasion Status||Population Status|
|NEP-III||Alaskan panhandle to N. of Puget Sound||1924||Def||Extinct|
|P293||_CDA_P293 (Strait of Georgia)||1924||Def||Failed|
ReferencesAbe, Naoya (1983) Proceeding of the second international conference on the malacofauna of Hong Kong and southern China, Hong Kong University Press, Hong Kong. Pp. 381-392
2002-2016a Malacology Collection Search. http://clade.ansp.org/malacology/collections/
2006-2014b OBIS Indo-Pacific Molluscan Database. http://data.acnatsci.org/obis/
Carlton, James T. (1979) History, biogeography, and ecology of the introduced marine and estuarine invertebrates of the Pacific Coast of North America., Ph.D. dissertation, University of California, Davis. Pp. 1-904
Claremont, Martine; Vermeij, Geerat J.; Williams, Suzanne T.; Reid, David G. (2013) Global phylogeny and new classification of the Rapaninae (Gastropoda: Muricidae), dominant molluscan predators on tropical rocky seashores, Molecular Phylogenetics and Evolution 66: 91-102
Gillespie, Graham E. (2007) Distribution of non-indigenous intertidal species on the Pacific Coast of Canada, Nippon Suisan Gakkaishi 73(6): 1133-1137
Hanna, G. Dallas (1966) Introduced mollusks of Western North America, Occasional Papers of the California Academy of Sciences 48: <missing location>
2008-2021 Museum of Comparative Zoology Collections database- Malacology Collection. http://www.mcz.harvard.edu/collections/searchcollections.html
Huang, Zongguo (Ed.) (2001) <missing title>, Krieger, Malabar, FL. Pp. <missing location>
Tan, K. S.; Sigurdsson, J. B. (1990) A new species of Thais (Gastropoda: Muricidae) from Singapore and peninsular Malaysia, Raffles Bulletin of Zoology 38(2): 205-211
2002-2021 Invertebrate Zoology Collections Database. <missing description>
Wu, Jing-Ying; Liu, Yu-Chih; Meng, Pei-Jie; Chiu, Yuh-Wen; Liu, Li-Lian (2006) Local distribution and temperature preferences of predatory whelks (Thais spp.) in Taiwan: Implications for oyster culture, Journal of Shellfish Research 25(2): 379-384