Know your islands
The Queen Conch is essentially a large, vegetarian, marine snail native to the western Atlantic Ocean.
Demand for its delicious meat and beautiful shell have contributed to chronic over fishing and placed it under enormous stress throughout the Caribbean.
The Queen Conch is the second largest of the five Caribbean species of Strombus conch, capable of growing to an average adult length of eight to 10 inches.
From birth, it creates a hard shell to protect its soft body by excreting calcium carbonate – a compound present in many animals such as the skeletons of coral polyps as well as our own bones and teeth.
The mantle, a layer of skin surrounding the foot and lining the shell wall, discharges the calcium carbonate as a liquid which then hardens to form the shell.
Conchs grow their shells in a clockwise spiral until a lip begins to form.
As the conch matures, it grows a fragile, flared lip that forms the base of the shell.
This helps to prevent the conch from being overturned by wave action during rough weather.
Once the lip forms, the shell ceases most of its growth in length and begins to gradually thicken as the conch ages. The development of the lip means that the conch is now, basically, fully grown, however it is not yet sexually mature.
Sexual maturity comes at about three – four years of age. At this point, it will have reached a length of approximately eight inches. Breeding and spawning activity is most prevalent during the warmest months with some activity occurring year-round in warmer climes.
Females like current-swept, sandy or gravel bottoms upon which to lay their eggs.
During spawning the eggs are coiled inside a continuous, clear tube which is camouflaged by grains of sand attached to its sticky surface. The egg mass is capable of containing about 300,000 to 500,000 eggs.
Each female can lay around six egg masses during any one spawning season. It is important to note that spawning females should remain undisturbed during this vital reproductive act.
The drastic decline in conch populations across the Caribbean due to over-fishing, led to it being placed on the Convention on International Trade in Endangered Species’ list in 1992. This means that member nations are obliged to have a fisheries management plan in place in order to export Queen Conchs.
Nevertheless, conch populations remain in an extremely fragile condition.
One estimate suggests that out of 400,000 offspring, less than one conch will survive into adulthood. This alarming statistic, coupled with other environmental and human pressures, signals a worrying time for the Queen Conch.
The Cayman Islands’ Department of Environment conducts an annual conch survey to monitor the success of marine parks and replenishment zones in stabilising existing populations. In addition, they continue to recommend a reduction in legal catch limits to supplement their efforts and help protect the Queen Conch for future generations.
Conch season is closed May 1 through October 31, with a catch limit of five per person or 10 per boat per day, whichever is less. No one may purchase or receive more than five conch from Cayman waters per day. For more information see our sustainable seafood program Cayman Sea Sense. For more information on the Trust’s various historic and natural sites, please visit our website, particularly the Information Sheets drop-down menu on the bottom left. Photos provided by the National Trust.
Grow Cayman Plants and encourage Cayman Wildlife! For more information, to share your knowledge or if you would like to get involved with the many activities in the National Trust’s Know Your Islands Program, please visit www.nationaltrust.org.ky, or call 949-0121.
Last week’s answer: Thatch roofing was replaced by corrugated ‘zinc’ which was hotter to live under, but did not need to be replaced as often as thatch roofing.
Trivia question: When was the first map to show the Cayman Islands with any accuracy created? Look for the answer in next week’s feature!