Did You Know?

Knobbed whelks (Busycon carica) are a predatory type of sea snail. Eeek! But don't worry, your toes are safe! Although they are carnivorous, knobbed whelks tend to prey on bivalves, such as hard clams, oysters, and something called incongruous arks (look it up!).

They grasp prey with their all-purpose "foot," then pry open the shell of their soon-to-be dinner using the lip of their own shell. Inserting a proboscis, they then feed. They can also use their radula, a sort of ribbon dotted with thousands of tiny teeth, to drill a hole through the prey’s shell. They retreat into their shell using something like a tiny trap door called an operculum, sometimes referred to as a “shoe.” If the shoe fits, wear it!

What is a knobbed whelk? • A marine gastropod (snail) • A mollusk • An invertebrate (having no spine)

Knobbed whelks are dextral, meaning their shells twine and open to the right. Unlike lightning whelks, which look very similar to knobbed whelks, but open to the left. Whelks grow by producing turns and whorls in its shell around a central axis. They can be “played” like a musical instrument. Cut the tip of the spire, press it to your lips and voila! A mini bugle.

Other creatures will take over empty whelk shells, such as hermit crabs, like the one seen peeking out here.

The egg casing of a knobbed whelk can contain up to 40 capsules, with each capsule containing up to 100 fertilized eggs. Females lay egg strings twice annually, with fall (Sept/Oct) being the most productive season. The long egg casings, which resembled coiled snakeskins when washed up on shore, are sometimes called “mermaid’s necklace” or “fisherman’s soap”.

How long knobbed whelks have existed