The knobbed whelk (''Busycon carica'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of very large

predatory Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, or in the US, a

whelk Whelks are any of several carnivorous sea snail species with a swirling, tapered shell. Many are eaten by humans, such as the common whelk of the North Atlantic. Most whelks belong to the family Buccinidae and are known as "true whelks." Othe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Busyconidae The Busyconidae are taxonomic family of large sea snails, often known as whelk Whelks are any of several carnivorous sea snail species with a swirling, tapered shell. Many are eaten by humans, such as the common whelk of the North Atlanti ...

, the busycon whelks. The knobbed

is the second largest species of busycon whelk, ranging in size up to 12 in (305 mm).

Distribution

Knobbed whelks are native to the

North Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for ...

coast of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

from

Cape Cod, Massachusetts Cape Cod is a peninsula extending into the Atlantic Ocean from the southeastern corner of Massachusetts, in the northeastern United States. Its historic, maritime character and ample beaches attract heavy tourism during the summer months. The ...

to northern

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

. This species is common along the

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

coast. It is the state shell of

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

and

Shell description

The shell of most knobbed whelks is dextral, meaning that it is right-handed. If the shell is held in front of the viewer, with the spiral end up and the opening facing the viewer, the opening will be on the animal's right side. The shell is thick and strong and has six clockwise coils. The surface is sculpted with fine striations and there is a ring of knob-like projections protruding from the widest part of the coil. The color is ivory or pale gray, and the large

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

(the inside of the opening) is orange. The canal inside is wide and the entrance can be closed by a horny oval operculum.Knobbed Whelk: Shell Money
Retrieved 2011-11-28.

Habitat

The knobbed whelk lives subtidally and is migratory, alternating between deep and shallow water, depending on the time of year. During the

weather extremes Extreme weather includes unexpected, unusual, severe, or unseasonal weather; weather at the extremes of the historical distribution—the range that has been seen in the past. Extreme events are based on a location's recorded weather history. Th ...

of the summer and winter months, these sea snails live in deep water, at depths of up to 48 m. In the milder weather of the spring and fall they live in shallow water, on near-shore or intertidal mud flats and sand flats. On the shallow-water mud flats whelks

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

s, clams, and other marine bivalves. They wedge a bivalve open using the edge of their shell, and insert their long proboscis to eat the flesh of their victim. They rasp at the flesh using their

radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...

, a rough tongue-like organ that has thousands of tiny denticles (tooth-like protrusions). Knobbed whelks are slow moving odour-mediated predators that have a considerable ability for temporal integration of signals and can successfully navigate prey odour plumes in naturally turbulent environments.

Reproduction

Mating and egg laying occur during the spring and fall migration. Internally fertilized eggs are surrounded by a transparent mass of

albumen Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens, it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms aro ...

, a gel-like material, and are laid in protective flat, rounded egg capsules joined to form a paper-like chain of egg cases, commonly called a "Mermaid's Necklace". On average each capsule contains 0–99 eggs, with most strings having 40–160 capsules. After laying their egg cases, female knobbed whelk will bury one end of the egg case into the substrate, thus providing an anchor for the developing fertilized eggs and preventing the string of egg cases from washing ashore where it would dehydrate. Fertilized eggs develop in the capsules. Young emerge with a shell approximately 2–4 mm in length. Young are preyed upon by crustaceans, horseshoe crabs, and fish, primarily drum species. Adult whelks are eaten by loggerhead sea turtles.

Human use

As with

conch Conch ( , , ) is a common name of a number of different medium-to-large-sized sea snails. Conch shells typically have a high Spire (mollusc), spire and a noticeable siphonal canal (in other words, the shell comes to a noticeable point on both ...

s, the knobbed whelk is used by humans as food in such dishes as salads (raw), burgers, fritters, and

chowder Chowder is a thick soup prepared with milk or cream, a roux, and seafood or vegetables. Oyster crackers or saltines may accompany chowders as a side item, and cracker pieces may be dropped atop the dish. Clam chowder from New England ...

s. As is also true of

shells, the shell of the knobbed whelk can be made into a natural

bugle The bugle is a simple signaling brass instrument with a wide conical bore. It normally has no valves or other pitch-altering devices, and is thus limited to its natural harmonic notes, and pitch is controlled entirely by varying the air a ...

by cutting off the tip of the

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spire ...

in order to form a mouthpiece. Historically, American Indians used the knobbed whelk as a component in

wampum Wampum is a traditional shell bead of the Eastern Woodlands tribes of Native Americans. It includes white shell beads hand-fashioned from the North Atlantic channeled whelk shell and white and purple beads made from the quahog or Western ...

, the shell beads exchanged in

for trade.

References

{{DEFAULTSORT:Knobbed Whelk Busyconinae Symbols of Georgia (U.S. state) Gastropods described in 1791 Symbols of New Jersey Taxa named by Johann Friedrich Gmelin