What Conchs Eat and Who Eats Conchs
Conchs are vegetarians. They graze the seagrass beds of the Caribbean and its vicinity. Sticking out their claw-like operculum and digging it into the sand in front of them, they make use of their strong muscular foot, which is attached to the operculum, and pull the rest of their body forward. In this manner they can pass through over 400 feet of seagrass in a single night, the time when conchs most frequently move about.
Conchs do not eat seagrass. They scrape off the covering of algae that adhere to the blades of grass. The seagrass remains unscathed. To accomplish this the conch uses an organ in its mouth called a radula, which according to Webster's New Collegiate Dictionary, is "a horny band or ribbon that bears minute teeth on its dorsal surface and tears up food and draws it into the mouth.
Conchs, in turn, are eaten by several species of predators. First and foremost are human beings. Humans get conchs out of their shells by using tools such as hammers and knives or stoves or freezers. Humans have developed quite a taste for this Caribbean mollusk and every year they consume millions of pounds of conch meat.
The spotted eagle ray is another predator that enjoys a conch dinner. These big, beautiful rays can often be seen gliding over the seagrass beds. (A good place to see spotted eagle rays is Rendezvous Bay on the south coast of the island.) Spotted eagle rays, which can have wingspans of over six feet and weigh more than 500 pounds, can break open a large queen conch shell with one crunch of their powerful jaws.
Interestingly, marine biologists have yet to find pieces of shells in the stomachs of those rays unfortunate enough to be the subject of such an experiment. This indicates that spotted eagle rays can somehow separate the shell from the conch meat and dispose of it.
The seemingly innocuous starfish is another conch predator and has developed a unique way of feasting on conch. Because the conch's operculum does not completely close off the entrance to the conch's shell, the starfish can insert one of its arms in the opening, preventing the conch from slipping further back. Then the starfish does an amazing thing; it forces its own stomach out of its body, sticks it inside the conch and digests the conch right inside its own shell.
Divers and snorkelers will often pick up a conch shell only to find it inhabited by a hermit crab. Hermit crabs live in the shells of mollusks that, for some reason or other, have left their homes. The hermit crab will force the conch out of its shell by turning it upside down so that it can't get away. It then inserts its powerful claws into the shell opening and pulls the conch out. The hermit crab then devours the unprotected animal, and takes over the shell.
The octopus is another animal that dines on conch. It can extract a conch from its shell by using its suction cup-like arms. Evidence of this can often be observed by snorkelers who may notice piles of empty conch shells surrounding an octopus's den.
Young, very small conch, called rollers, are vulnerable to even more predators, such as sharks and turtles that will eat them, shell and all. Even tinier conch can fall prey to lobsters and triggerfish that will work at crushing or grinding away the conch's shell, little by little, until they can finally get to the meat inside.
The conch is a truly a tasty dish, so tasty that it is disappearing quickly. Between 1970 and 1980 it is estimated that the conch population decreased by 90% and the decline continues. Human beings may have to curtail their appetite for these creatures, as well as show a greater respect for the seagrass environments that supports them, so that future generations of people, starfish, spotted eagle rays, hermit crabs, sharks, lobsters and triggerfish will have the opportunity to enjoy a hearty conch meal every now and then.