Soft Coral—Flower Animals of the Sea
WHAT do you think of when you hear someone mention coral?
Perhaps you think of it as the basic building material of which many tropical islands and sandy beaches are formed. If you live in the Caribbean, perhaps your house is built of coral blocks cut from the ground. Or perhaps a favorite piece of jewelry made of gem-quality coral comes to mind. This type of coral is, no doubt, what the writer of Proverbs was alluding to when describing how precious a good wife is to her husband.—Proverbs 31:10.
The individual coral animal, the polyp, begins life as a tiny mass of cells that is ejected from the parent body and swept along by ocean currents until it reaches a suitable site where it can anchor permanently. In stony coral, the skeleton begins to form soon after the larva is attached to a firm bottom and begins to secrete calcium carbonate to form a hard, stony external skeleton. These corals grow at the rate of up to four inches [a hundred mm] a year.
But have you ever thought of coral as a soft, delicate flower? There are several varieties of soft coral that, because of their varied shapes and colors, have been called flower animals. Soft corals also begin life as swimming larvae but seldom secrete massive calcium carbonate skeletons. These fleshy and treelike corals can therefore grow more rapidly than the stony corals and are far less permanent.
One such soft coral has a big, rubbery, treelike body and is called a flower animal because it resembles a beautiful flower, even though coral is animal rather than plant life. The tree coral is supported only by small needlelike calcite spicules (which resemble sliced almonds) and hydraulic pressure within the fleshy tissue of its body. These corals take in seawater to give form to their flesh, similar to the way heated air fills hot-air balloons, but the water pressure is not great, nor is the water hot. The pressure is enough, however, combined with the effect of the surrounding water, that the body and its branches are supported. Because of its structure, this variety of coral rarely grows to a height of more than three feet [1 m] and prefers lagoons and calm ocean locations.
When inflated to their treelike form, these tree corals are very beautiful, reminding the observer of a lovely multicolored flower garden filled with delicate blooms and blossoms. Visually, their translucent or transparent bodies delight the eye as they capture the ambient light and the coloration of the water, while supporting branches having white, yellow, gold, pink, red, or purple polyps.
Another type of soft coral is the daisy coral. Daisy coral is so named because of its great resemblance to its namesake, the daisy. There are several varieties of daisy coral, and they are distinguished by the number of “petals” (tentacles) surrounding the mouth of the polyp.
These delicate white or tan-and-white corals are not so colorful as the tree corals, but their size, long stems, and shape are delightful to observe on the reef. A colony may grow to be 15 to 20 feet [4 to 6 m] across and can give the diver a feeling of observing a field of daisies covering rolling foothills. Currents move the polyps and give the illusion of a breeze moving the daisies, causing them to sway gently in rhythm to the movement of water.
One of the divers’ favorite types of coral is the sea fan. A mature sea fan is a strikingly beautiful, majestic coral colony. The fan is a close relative to the soft corals, but because of its structure, it is designated as “horny coral.” This type of coral has polyps embedded in a soft layer of tissue that surrounds an internal, woodlike stalk. This stalk contains gorgonin (another common name for the sea fan is gorgonian), a protein resembling keratin, which is used in the biological production of fingernails, hair, and hooves.
The trunk of these fans is often very thick, strong, and rigid. As the branches reach outward to their extremities (often several feet), they become more flexible, gently waving in strong currents, which bring them the small organisms upon which they thrive.
The sea fan ranges in color from brown, gold, and orange to purple and brilliant red. It is particularly beautiful when the delicate-appearing polyps emerge to feed and completely cover the branches with their graceful featherlike tentacles.
When considering coral, then, one must consider that not all coral is precious or functional as a building block, but all coral is beautiful. It gives us once again the opportunity to reflect upon the great variety of life found in creation and the many variations within each kind of life. When we do, we stand in awe of the creative ability, imagination, and ingenuity of the Creator. (Psalm 104:24) Who of man can even begin to comprehend Jehovah’s wisdom and knowledge!—Romans 11:33.
And when we consider life in the oceans, which cover over 70 percent of the earth’s surface, we marvel at the words of the psalmist who stated at Psalm 104:25: “As for this sea so great and wide, there there are moving things without number, living creatures, small as well as great.”
[Pictures on page 24, 25]
Top: Leather daisy
Bottom: Soft coral trees
Opposite page: Top: Trunk of soft coral
Bottom: Soft coral and small grouper
[Pictures on page 26]
Top: Scarlet sea fan
Bottom: Gold sea fan