Text Size: A  A  A

Veined Rapa Whelk

Rapana venosa

The inside of a veined rapa whelk shell is deep orange. (U.S. Geological Survey/Bugwood.org)
The inside of a veined rapa whelk shell is deep orange. (U.S. Geological Survey/Bugwood.org)

The veined rapa whelk is a large, predatory snail that lives in the lower Chesapeake Bay. It is an invasive species.

Appearance:

  • Heavy, rounded shell with a short spire (tip) and large body whorl
  • Shell is almost as wide as it is long, giving it a boxy appearance
  • Varies in color from gray to reddish-brown with dark brown dashes on the spiral ribs
  • Most shells have distinctive black veins throughout
  • Inside of the shell is deep orange
  • Grows 6-7 inches long

Habitat:

  • Burrows deeply into sandy areas of the Bay’s bottom
  • Tolerates large temperature fluctuations, polluted water and low oxygen levels
  • May migrate to deeper waters in winter to avoid freezing surface waters

Range:

  • Found in the lower Chesapeake Bay along the western shore of Virginia from New Point Comfort to Cape Henry and into the James and York rivers
  • Native to the Sea of Japan and the Bohai, Yellow and East China seas in Asia

Feeding:

  • Preys upon bivalves such as clams, oysters and mussels
  • Smothers its prey by wrapping itself around the hinge of its prey’s shells, then feeding between the opened shells

Predators:

  • Turtles and other seasonally migrating large predators may prey on young rapa whelks
  • Once rapa whelks reach their adult size, they likely do not have any predators in the Bay

Reproduction and Life Cycle:

  • During warmer months, rapa whelks lay groups of egg cases attached to rocks and other hard surfaces. Rapa whelk egg cases look like small mats of yellow shag carpet. Each egg case is approximately 2 inches tall and one-quarter of an inch thick.
  • In approximately 18-26 days, tiny free-swimming larvae hatch from a small hole at the top of each egg case
  • After 4-6 weeks, larvae settle to the bottom and eventually grow into hard-shelled adults
  • Young grow rapidly during their first year and can reproduce by their second year
  • Can live longer than 10 years

Other Facts:

  • Also known as the Asian rapa whelk
  • The veined rapa whelk is a gastropod, a type of mollusk that includes whelks, snails and slugs
  • Discovered in the Chesapeake Bay in 1998 by a trawl survey group at the Virginia Institute of Marine Science (VIMS)
  • Likely introduced into the Bay through ships that released ballast water containing tiny rapa whelk larvae
  • It’s important to report rapa whelk sightings to VIMS so scientists can track their distribution in the Bay. If you think you have found a veined rapa whelk, call the VIMS Rapa Whelk Reporting Line at (804) 684-7361.

Sources and Additional Information:




Click tabs to swap between type and habitat.

410 Severn Avenue / Suite 112
Annapolis, Maryland 21403
Tel: (800) YOUR-BAY / Fax: (410) 267-5777
Directions to the Bay Program Office
Terms of Use | Privacy Policy
©2012 Chesapeake Bay Program | All Rights Reserved