Conch, queen

Strombus gigas

phylum: Mollusca

class: Gastropoda

order: Archaeogastropoda

family: Strombidae

status: No special status

range: Bahamas, Bermuda, Cuba, Dominican Republic, Haiti, Jamaica, Leeward Islands, Puerto Rico, Trinidad and Tobago, USA (Florida), Virgin Islands (British), Virgin Islands (US), Windward Islands

Description and biology

The queen conch (pronounced KONGK), also called the pink conch, has a heavy, solid, spiral shell with a broad, flaring lip. At maturity, the conch can weight up to 5 pounds (2.3 kilograms) and its shell can reach a length of 8 to 12 inches (20 to 30.5 centimeters). The shell's exterior is light pink to white in color. The inside is a glossy pink, yellow, or peach. A row of blunt spines line the upper portion of the shell below the apex (top). Queen conchs are "right-handed"; that is, the shell coils to the right when one looks down on the apex of the shell.

When just a young mollusk, the conch has no bone structure, just a soft body. This body consists of a long and narrow foot, a head with yellow eyes on the end of two

protruding stalks, and a snout-like mouth between them. A pair of slender tentacles also appear on the head. A fleshy covering of yellow or orange skin, called the mantle, encloses the foot and head.

At the end of the conch's foot is a sickle-shaped claw called an operculum (pronounced o-PER-cue-lum). The conch uses its operculum to dig into the sea floor to pull its body forward in short hops and to right itself when turned over.

The shell of a young conch does not have the flaring lip of an adult. It is very delicate. The spines are pointed and not yet blunted. The shell is composed mainly of calcium carbonate. The mantle of the conch excretes this material as a fluid, which quickly hardens to a crystal form. As the conch ages, it continues to build its shell, increasing the thickness. The shell can grow as much as 3 inches (7.6 centimeters) per year. The lip begins to develop after two to three years.

Queen conchs are primarily nocturnal, emerging at night to feed on a variety of algae species and sea grasses. Young conchs are preyed on by crabs, sharks, loggerhead turtles, groupers, snappers, and octopi. Adult conchs are preyed on mainly by humans.

Female queen conchs breed during the summer months in shallow waters in sandy areas behind reefs. After mating with a male, the female stores the sperm for several weeks until she is ready to release her eggs. A female can lay eight or more egg masses each season. An egg mass consists of a single continuous sticky tube that contains between 400,000 and 750,000 eggs. The tube folds back on itself, producing a slightly curved mass. Once the eggs are laid, the female releases the stored sperm to fertilize them. The eggs hatch after three to five days, and the shelled larvae emerge to begin their period of development. Queen conchs have an estimated life span of six to ten years. Some may live longer.

Habitat and current distribution

The queen conch is found in Bermuda, southeast Florida, and the West Indies. Actual population numbers are currently unknown. The queen conch has declined near areas inhabited by humans, but it may still be common in more remote areas.

The species inhabits sandflats, gravel, and coral rubble in shallow warm water near islands and coral reefs where sea grass is abundant. As they mature, the conchs move from shallow, inshore sands to deeper offshore sites. Although they have been found in water at depths up to 400 feet (122 meters), it is rare for conchs to inhabit water deeper than 70 feet (21 meters).

History and conservation measures

The queen conch has always served as an important food source for people in the Caribbean. The protein-rich meat of the conch makes a nutritious meal. But rising human populations throughout the Caribbean have brought increased pressures on the conch. Not only is it eaten, it is also sought out by fishermen for use as bait. And its shell is highly prized by tourists from around the world. The queen conch is now rare in areas where it formerly was common, such as the Florida Keys.

Captive-breeding programs have so far proved useless. Although the conch is easy to raise in captivity, it does not fare well when placed back in its ocean habitat. Predators quickly eat captive-bred young conchs.

The queen conch is protected by international treaties. The International Union for Conservation of Nature and Natural Resources placed the species in a commercially threatened status in the 1990s, but later removed it. Greater enforcement of these restrictions is necessary to ensure the survival of the species.