One of the more common subjects of underwater photography is a Flamingo Tongue poised on a sea fan. Even the most amateur of photographers can take a good shot since the Flamingo Tongue is very slow and its leopard spotted shells make beautiful contrast to the purple and red sea fans upon which we find them. When teaching underwater photography or leading divers, I count on Flamingo Tongues to provide subject matter.
Flamingo Tongues, Cyphoma gibbosum, are marine mollusks of the family ovulidae, marine snails closely related to cowries. They are gastropods; previously called uni-valves for they have only one shell rather than two (as do oysters and scallops). They live on coral reefs in the tropical waters of the Western Atlantic and Caribbean. The Flamingo Tongues’ cousins, the Fingerprint Tongues, Cyphoma signatum, also live in the Western Atlantic and Caribbean but sightings of them are rare.
There are four other species, however, they are rarer than the Fingerprint Tongues and, while there is mention of them in scientific literature, it is almost impossible to find photographs or detailed information.
Except for the coloration of their mantles, the Flamingo and Fingerprint Tongues seem to be identical. Their shells, when mature, are approximately 1 inch long, tapering slightly on both ends with a somewhat thicker, domed center. From white to apricot in color, the shells have long been used in jewelry and decorative items.
Tongue mollusks feed upon the tiny polyps of soft, branching gorgonian corals more commonly known as sea fans and sea whips. While we might assume their feeding damages the coral, the damage is only temporary and the devoured polyps repopulate.
Often found in pairs, studies indicate that the pairs usually consist of one male and one female. Like many other mollusk species, they locate each other by leaving mucous trails along the coral. Some scientists believe that adult Tongue mollusks aggregate at certain times during the year when they disperse chemical signals known as pheromones over many sea miles. No courting rituals occur and mating lasts up to three hours.
Female Tongues deposit tiny egg capsules in the bare spots created as they feed upon the gorgonians. The egg deposit activity generally occurs during lunar cycles and females can deposit multiple groups of eggs.
About 10 days after the eggs are deposited, microscopic larvae hatch and become part of the floating mass of life known as sea snow or plankton. No one knows how long it is before the larvae develop into juvenile Tongues but eventually the juveniles land on a coral reef where they fix themselves to the underside of the gorgonians. At this stage, the juveniles are no bigger than a grain of rice and appear to be either translucent or part of the gorgonian since some take on the color of the host coral. As with so many other marine species, very little is known about the life cycles of any of the Tongue mollusks so there is no data on life spans, age of maturity, length of the larval stage, growth of the juveniles. There is so much yet to learn.
The only apparent difference between the Flamingo Tongue and the Fingerprint Tongue is the pattern and coloration. As in the photo, the Flamingo Tongue has leopard-like spots. The Fingerprint Tongue has oval-like spots filled with fine, dark, curving lines resembling fingerprints. If we remove their spots so that all we have left are the shells, none of us would know which one was the Flamingo and which was the Fingerprint. Once the Tongue shells die, their leopard spots and fingerprints disappear.
Why do the spots and fingerprints disappear? The spots are not actually on the shell. The spotted patterns are present only on the mantle, which is an extension of the sac that protects the Tongues’ internal organs. The Tongue mollusks extend their mantles outside of their body cavities and cover their shells.
Extending the mantles to cover their shells is a defense mechanism. There are toxins in the soft corals upon which the Tongues feed. The toxins do not affect the Tongues but they make the Tongue mollusks distasteful to most predators. These toxins are stored in the mantles. The bright spots and patterns warn most fish away although Caribbean lobster, hogfish, and puffer fish seem immune to the taste, making them the main Cyphoma predators.
The colorful protective mantles of the Flamingo and Fingerprint Tongues may be the very thing that leads them to their demise, however. Not that long ago, the Flamingos were plentiful throughout the Western Atlantic and Caribbean but they are becoming more difficult to find. Most divers and swimmers are unaware that the very spots and fingerprint patterns protecting the mollusks from marine predators are merely thin membranes. Once Tongues are collected from the reef, the patterned membranes shrivel up and crumble away as the helpless creature within the shell dies.
Becky Bauer became a scuba instructor and award-winning journalist covering the marine environment in the Caribbean after 30 years as a wild and domestic animal rescuer, rehabber, and educator in the states. She is a contributing photographer to NOAA.