Knobbed Whelk – Busycon carica

Channeled Whelk – Busycon canaliculatum

Color: The shell of both species is yellowish red or orange inside and pale, buffy gray outside. 

Size: Channeled Whelk – up to 8 inches long. Knobbed Whelk – up to 9 inches long, 4 ½ inches wide

Habitat: Sandy or muddy bottoms

Seasonal Appearance: All year.

Sensitivity to Human Action                                              







Distinguishing Features and Behaviors:

     Whelks are large snails with massive shells common along the shore of Narragansett Bay. The two most common species in the Bay are the knobbed whelk and the channeled whelk.

     Knobbed whelks are the largest marine snails in Narragansett Bay. The knobbed whelk is pear-shaped with a flared outer lip and knobs on the shoulder of its shell. The channeled whelk is generally smaller than the knobbed whelk, and has spiral lines instead of knobs deeply channeled on its shell.

     Both species of whelk have an operculum, a hard, brownish black, shell-like organ used to close the opening of the shell to protect the whelk. The feeding organ is called the proboscis, which includes the mouth, esophagus, and radula. Whelks use the radula, a drill like organ with small, horny teeth, for rasping either flesh or plants. Whelks also have a long, tubular siphon, which they use to draw in oxygenated water.

     Both whelk species are aggressive predators, preying on other invertebrates, particularly clams. They feed by prying a gap between the two valves of the clam and forcing the shell open with their strong muscular foot. As soon as the valves open, even the tiniest amount, the whelk wedges the sharp edge of its shell in, inserts the proboscis, and devours the soft body of the clam.

     Mating occurs by way of internal fertilization and separate sexes. The egg casing of the whelk is a long strand of yellowish parchment-like disks that resemble a necklace. Egg cases can be about 2 to 3 feet long and have about 70 to 100 capsules, each of which can hold 20 to 100 eggs. Newly hatched channeled whelks with their shells on escape from small holes at the top of each egg case. Egg cases are sometimes found along the Bay shoreline, washed up with the high-tide debris.

Relationship to People:

     Both the channeled and knobbed whelks scavenge and hunt for food and are often found in crab traps and lobster pots, presumably stealing the bait.

     Whelks are a favored food in the Northeast and are harvested all along the Atlantic coast. Scungili, a popular Italian dish, is made from the foot of both species of whelk