A queen conch (Lobatus gigas) is an invertebrate mollusk that produces what many people think of as the iconic seashell. This shell is often sold as a souvenir, and it's said you can hear the sound of ocean waves if you put a conch (pronounced "konk,") shell to your ear (although what you're actually hearing is your own pulse).
Fast Facts: Conch
- Scientific Name: Lobatus gigas
- Common Names: Queen conch, pink conch
- Basic Animal Group: Invertebrate
- Size: 6-12 inches
- Weight: Up to 5 pounds
- Lifespan: 30 years
- Diet: Herbivore
- Habitat: Off coastlines adjacent to the Caribbean Sea
- Conservation Status: Not Evaluated
Conchs are mollusks, marine snails that build elaborate shells as a home and a form of protection from predators. The shell of the queen conch or pink conch shell ranges in size from about six inches to 12 inches in length. It has between nine and 11 whorls on the protruding spire. In adults, the expanding lip points outward, rather than curving inward, and the last whorl has a strong spiral sculpture on its surface. Very rarely the conch may produce a pearl.
The adult queen conch has a very heavy shell, with a brown horny organic exterior cover (called periostracum) and a bright pink interior. The shell is strong, thick, and very attractive, and is used to make shell tools, as ballast, to form jewelry. It is often sold unmodified as a collectible and the animal is also fished and sold for its meat.Damocean/Getty Images
There are over 60 species of sea snails, all of which have medium- to large-sized (14 inches) shells. In many species, the shell is elaborate and colorful. All conchs are in the Kingdom: Animalia, the Phylum: Mollusca, and the Class: Gastropoda. True conchs like the queen are gastropods in the family Strombidae. The general term "conch" is also applied to other taxonomic families, such as the Melongenidae, which include the melon and crown conchs.
The queen conch's scientific name was Strombus gigas until 2008 when it was changed to Lobatus gigas to reflect current taxonomy.
Habitat and Distribution
The conch species live in tropical waters throughout the world, including the Caribbean, West Indies, and the Mediterranean. They live in relatively shallow waters, including reef and seagrass habitats.
Queen conchs live in several different habitat types in the Caribbean, along the Gulf coasts of Florida and Mexico, and in South America. At different depths and aquatic vegetation, their shells have different morphologies, different spine patterns, and various overall lengths and spire shape. The samba conch is the same species as the queen, but compared to a typical queen conch, the samba lives in a shallow environment, is much shorter and very thickly shelled with a darker periostracum layer.
Diet and Behavior
Conchs are herbivores that eat sea grass and algae as well as dead material. In turn, they are eaten by loggerhead sea turtles, horse conchs, and humans. A queen conch can grow to be over a foot long and can live for as long as 30 years-other species have been known to live to 40 or more.
Queen conch diets, like most of the conchs in the family, are herbivorous. Larvae and juveniles feed mainly on algae and plankton, but as growing subadults, they develop a long snout that allows them to select and consume bigger pieces of algae, and as juveniles they feed on seagrass.
Adult conchs wander for miles instead of staying in one place. Rather than swimming, they use their feet to lift and and then throw their bodies forward. Conchs also are good climbers. The average home range of a queen conch varies from a third of an acre to nearly 15 acres. They move within their range at the greatest speed in the summer during their reproductive season, when males search for mates and females look for egg-laying habitats. They are social creatures and reproduce best in aggregations.
Reproduction and Offspring
Queen conchs reproduce sexually and can spawn year-round, depending on latitude and water temperature-in some locations, females migrate from offshore feeding areas in the winter to summer spawning grounds. Females can store fertilized eggs for weeks and multiple males can fertilize any single egg mass during that time. The eggs are laid in shallow coastal waters with sandy substrates. Up to 10 million eggs can be laid by a single individual each spawning season, depending on the availability of food.
Eggs hatch after four days and the planktonic larvae (known as veligers) drift with the current for between 14 to 60 days. After reaching lengths of about a half-inch, they sink to the sea bottom and hide. There they morph into juvenile forms and grow to about a 4-inch length. Finally, they move into nearby seagrass beds, where they aggregate in masses and stay until sexually mature. That happens at about 3.5 years of age when they reach their maximum adult length and their outer lips are at least 0.3-0.4 inches thick.
After the queen conch reaches maturity, the shell stops growing in length but continues to grow in breadth and its outer lip begins to expand. The animal itself also stops growing, except for its sexual organs which continue to grow in size. The lifespan of a queen conch is approximately 30 years.
The International Union for Conservation of Nature (IUCN) has not as yet evaluated conchs for their status. But conchs are edible, and in many cases, have been overharvested for meat and also for souvenir shells. In the 1990s, queen conchs were listed in Appendix II under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) agreement, regulating international trade.
Queen conchs are also harvested for their meat in other areas of the Caribbean where they are not yet endangered. Much of this meat is sold to the United States. Live conchs are also sold for use in aquariums.
- Boman, Erik Maitz, et al. "Variability in Size at Maturity and Reproductive Season of Queen Conch Lobatus Gigas (Gastropoda: Strombidae) in the Wider Caribbean Region." Fisheries Research 201 (2018): 18-25. Print.
- "Final Status Report: Queen Conch Biological Assessment." Peer Review Plans, National Oceanic and Atmospheric Agency (NOAA), 2014.
- Kough, A. S., et al. "Efficacy of an Established Marine Protected Area at Sustaining a Queen Conch Lobatus Gigas Population During Three Decades of Monitoring." Marine Ecology Progress Series 573 (2017): 177-89. Print.
- Stoner, Allan W., et al. "Maturation and Age in Queen Conch (Strombus Gigas): Urgent Need for Changes in Harvest Criteria." Fisheries Research 131-133 (2012): 76-84. Print.
- Tiley, Katie, Mark A. Freeman, and Michelle M. Dennis. "Pathology and Reproductive Health of Queen Conch (Lobatus Gigas) in St. Kitts." Journal of Invertebrate Pathology 155 (2018): 32-37. Print.