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Educational Series in Affiliation with

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from The Uncommon Guide to Common Life on Narragansett Bay

A continuing series that describes the common fish, invertebrates, plants, water birds, and marine mammals that share our Bay.


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This month.....
Whelks
WHELK 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, 4-1/2 inches wide

Habitat: Sandy or muddy bottoms

Seasonal Appearance: All year

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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 Narrgansett 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, browning 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 yellowing parchmentlike 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 whelks with their shells on escape frm 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 whelk scavenge and hunt for food and are often found in crab trabs 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.

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