Knobbed Whelk (Busycon carica Gmelin, 1791) Knobbed Whelk (Busycon carica Gmelin, 1791) Knobbed Whelk (Busycon carica Gmelin, 1791)

Knobbed Whelk
Busycon carica Gmelin, 1791
Second image: egg case.
Bottom image: juvenile whelks from the egg case.

Knobbed Whelk:
Shell Money

By Patricia B. Mitchell.

The Knobbed Whelk shell grows with six clockwise twists, or coils. The aperture (opening) of the mollusk is on the right side as you look down at it. This configuration is referred to as dextral. The adult shell may reach a length of 9 inches, and is very sturdy. It is a yellowish-gray color, with a cream or orange interior. The aperture of the shell is big and oval, and the canal is long and wide. There is an oval operculum composed of a horny material. This “door” of the aperture can be drawn in when the snail desires.

The living Knobbed Whelk is a meat-eater. He hunts for shellfish like clams, oysters, mussels, etc. He “pulverizes” a victim by hitting his heavy shell against the prey, then he wedges the edge of his shell between the bivalve halves, and pries the shell apart. Next he inserts his spout-like probiscis into the bivalve and sucks out the soft parts.

The spires of the Knobbed Whelk shell are decorated with knob-like projections. The columellas of this mollusk and the Channeled Whelk were used by early Native Americans as one form of money. They cut the twisted core, or central axis, of the gastropod into elongated trading beads.

The meat of the Whelk is quite edible, with a flavor similar to that of clams. It can be used in chowder, and is good in salsa dishes.

The egg cases of the Knobbed Whelk (which are called Venus necklaces) may be found along the beach during the summer. Each small disk of the “necklace” contains a hundred or more eggs, many of which never hatch because they are eaten by just-hatched siblings! Eventually the surviving “babies” eat their way out of the egg case.

The gastropod lives just offshore from Massachusetts to northwest Florida. It is the state shell of New Jersey.


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