Retrieving species information. This may take a few seconds.
Retrieving gallery information. This may take a few seconds.
A large, active predatory snail, growing up to 18 cm in length. It has a rounded, knobbly shell, with orange internal coloration. External coloration is grey with dark veins. The shell opening is large, with small teeth on the outer lip and a short, open siphon canal.
The rapa whelk is not currently thought to be established in GB. Several individuals were caught by fishermen in 2005 in the North Sea 30 km south of the Dogger Bank suggesting that the species may be present offshore.
Usually found on and under soft sediments from 3 – 90m water depth. The species is also occasionally found on hard and mixed substrates. In particular, individuals congregate on hard-surfaces such as rocky outcrops and man-made structures to reproduce in late spring and summer months.
|Status in England:||Non-Native|
|Status in Scotland:||Non-Native|
|Status in Wales:||Non-Native|
|Location of first record:||No British records to date|
|Date of first record:||Unknown|
Native to the Sea of Japan, Yellow Sea, Bohai Sea, and the East China Sea to Taiwan.
Isolated records exist for the southern North Sea, in GB waters approximately 30 km south of the Dogger Bank, the Netherlands coast and in shallow waters off the coast of Brittany.
A major vector for transportation worldwide is through shipping, in particular larval transport in ballast water. It may also be unintentionally transported with aquaculture products; it is thought to have been introduced into the Black Sea in 1947 with oysters imported for culture. Once a founder population is established, natural range extension can occur rapidly through larval dispersal via tidal currents, migration of juvenile or adult whelks, or human-mediated means.
There is currently no evidence that the species has established populations, or show active breeding or multiple year classes in GB waters. A small but stable reproducing population is established in the Bay of Quiberon, Brittany, and recent sightings have been reported from the Dutch coast. Elsewhere the rapa whelk is invasive in the Chesapeake Bay area of North America, the Aegean and Adriatic Seas, the Black Sea and Uruguay.
Native range includes the Sea of Japan, Yellow Sea, Bohai Sea and the East China Sea to Taiwan. Non-native distribution includes the Black Sea, the Aegean and Adriatic Seas, Uruguay and the Chesapeake Bay area of eastern USA. A small but stable reproducing population is established on the Brittany coast. In GB there is no evidence of established populations but an individual record of several rapa whelks was reported from offshore GB waters in 2005.
The rapa whelk is able to rapidly consume large quantities of prey and could become a serious competitor for the native common whelk. Reduced food availability may also impact other predators of bivalves including crabs, birds, fish and starfish. A decline in structure forming bivalves may affect local habitat, resulting in reduced refuge for juvenile crustaceans and other organisms.
The provision of larger shells to hermit crabs may allow increased growth and increased demand by hermit crabs on food resources.
The diet of this voracious predator includes molluscs of commercial interest including oysters, mussels and clams; it has been predicted that successful establishment of this species in Great Britain may threaten the bivalve industry. A rapa whelk of 14 cm is reported to be capable of consuming an eight cm hard clam in less than an hour.
Giberto, D.A., Bremec, C.S., Schejter, L., Schiariti, A., Mianzan, H. & Acha, E.M., (2006) The invasive rapa whelk Rapana Venosa (Valenciennes 1846): status and potential ecological impacts in the Rio de la Plata Estuary, Argentina-Uruguay. Journal of Shellfish Research, 25, 919-924.
Harding, J.M., Mann, R. & Kilduff, C.W. (2008) Influence of environmental factors and female size on reproductive output in an invasive temperate marine gastropod Rapana venosa (Muricidae). Marine Biology, 155, 571-581
Kerckhof, F., Vink, R.J., Nieweg, D.C. & Post, J.J.N., (2006) The veined whelk Rapana venosa has reached the North Sea. Aquatic Invasions, 1, 35-37.
Mann, R. & Harding, J.M., (2000) Invasion of the North American Atlantic Coast by a Large Predatory Asian Mollusc. Biological Invasions, 2, 7-22.
Sewell J., Pearce S., Bishop J. and Evans, J.L. (2008) Investigations to determine the potential risk for certain non-native species to be introduced to North Wales with mussel seed dredged from wild seed beds. CCW Policy Research Report No. 06/3. pp 82
ICES. (2004) Alien Species Alert: Rapana Venosa (veined whelk). Edited by Roger Mann, Anna Occhipinti, and Juliana M. Harding. ICES Cooperative Research Report No. 264. 14 pp
May 1st 2015
We try to keep these factsheets up to date, however if you notice any issues please contact us .