Description and characteristics
The veined rapa whelk (Rapana venosa) is a large gastropod mollusc with a thick, spiral, brown-grey shell with reddish veins. It has gills and a sharp radula, used to bore through the shells of other molluscs.
Habitat and distribution
It lives on sandy and muddy bottoms of the Black Sea, being an invasive species accidentally introduced, which has spread rapidly, including in areas near the Danube Delta.
Diet and behaviour
It is a carnivorous mollusc, feeding mainly on bivalves (mussels, clams), which it digs and opens with its radula. It is an active predator with major impact on native bivalves.
Reproduction
Reproduction occurs by laying egg masses, from which planktonic larvae hatch. It has high fecundity and spreads quickly.
Economic and ecological importance
It has economic value, being collected for its tasty flesh and shell. Ecologically, however, it is an invasive species that severely affects native bivalve stocks, including cultured mussels.
Threats and conservation
Being invasive, it represents a threat to marine biodiversity. Population control and monitoring are necessary to limit its ecological impact.
Fishing and legal minimum size
It is collected manually and by diving. In the table of minimum legal sizes, the veined rapa whelk (Rapana venosa) has a minimum size of 5 cm.
Conclusion
The veined rapa whelk is an invasive gastropod, economically important, but with significant ecological impact on marine bivalves in the Danube Delta area.