Most Unwanted: Asian rapa whelk
Rapana venosa
Habitat: Marine
Threat: Threatens marine ecosystem functioning
Status: Potential
Rapana venosa is a predatory marine snail which may impact both natural and cultivated populations of oysters, mussels and other molluscs. In areas where it has been introduced it has caused significant changes to the ecosystem. It has a fast growth rate and reproductive ability.
What is it?
It has a large heavy shell with a short spire. A very distinctive feature is the deep orange colour of the inside of the shell. The outer colour is variable from dull grey to red brown, with more or less conspicuous dark brown dashes on the spiral ribs, which tend to make an interrupted "vein-like" pattern throughout the entire shell.
Impact
The predatory impact of R. venosa has serious implications for both natural and cultivated populations of marine bivalves. R. venosa are very voracious predators and Rapana is blamed in the Black Sea for the decline of the native, edible bivalve fauna. They have caused significant changes in the ecology of bottom-dwelling organisms and have resulted in the near extinction of the Gudaut oyster. Please see the Global Invasive Species Database pages on this species for more information.
Where is it from?
Asia
Where is it now?
This species is now present in Europe and the US.
How can it get here?
Ballast water, Aquaculture and hull fouling are considered the main potential pathways to Ireland.
What you can do to prevent its arrival
Avoid hull fouling on your boats.
Never take oyster spat from an area known to have Rapena present and transfer to Ireland.
Report all sightings.
