Dancing Horses of the Sea
BY AWAKE! WRITER IN AUSTRALIA
THE couple share a blush of recognition. He seems to puff with pride, while she looks on with approval. They reach out to share a delicate touch, then a warm embrace. As the glow of dawn filters down on them, they ease into the rhythm of one of nature’s most elegant ballets—the dance of the sea horse.
“Sea horses are simply fascinating, unique, and charismatic,” says marine expert Dr. Keith Martin-Smith. In the past, though, people were unsure of just what to make of them. Early naturalists used the name Hippocampus, which was also given to the mythological fish-tailed horses that pulled the chariot of Poseidon, the Greek god of the sea.
It has been suggested that in medieval times, hucksters may have passed sea horses off as baby fire-breathing dragons. In truth, sea horses are simply bony fish—although they don’t look like most fish or swim like them. Drifting through water or hovering in aquatic space, they have been compared to dainty crystal horses and animated chess pieces.
Sea horses are found in most of the world’s warm coastal waters. They come in an incredible variety of shapes and sizes. Experts estimate that there could be from 33 to more than 70 different species. These include the pygmy sea horse, which could easily fit on your fingernail, and the potbellied sea horse, which can grow to over 13 inches [30 cm] in length.
No Teeth, No Stomach, No Problem!
With their curious arrangement of horselike head, bony body armor, and monkeylike tail, sea horses are better built for staying put than for speeding about. Most of the day, they seem content simply to wrap their tail around a suitable hitching post, or holdfast, and feed. If sea horses need to move, a tiny rear dorsal fin propels them along at a gentle pace, while side fins provide steering. By regulating the amount of air in their internal swim bladder, they are able to ascend or descend just like a submarine.
Feeding is serious business for hungry sea horses, and any small shrimps or crustaceans swimming past are quickly vacuumed into their bony snout. Since sea horses have no teeth or stomach to aid digestion, they must catch as many as 50 shrimps each day to obtain the nutrients they need to survive. This is no problem for these efficient hunters, since sea horses have excellent eyesight. One eye can peer ahead for prey while the other independently scans behind. Their eyes can also detect more color than the human eye can and see in more detail than most fish.
Sea horses must avoid becoming somebody else’s lunch. To evade such predators as crabs and turtles, many species can merge almost invisibly into their sea grass, coral, or mangrove habitat. Their blotchy skin patterns, their weedlike body growths, and their ability to transform their skin color dramatically in order to match their surroundings allow them to blend perfectly into the background. “Their body camouflage is so good that to see them you really have to be tuned in,” says researcher Rudie Kuiter.
Dance and Romance
Unlike most other fish, male and female sea horses pair for life and rarely stray far from each other. Every dawn, they affirm their union through a unique dance. “The sea-horse dance is so beautiful and graceful that it’s a joy to watch,” says sea-horse breeder Tracy Warland. When the dance ends, the sea horses return to their respective holdfasts to feed for the rest of the day. The mating dance is more involved. As the female approaches the male, he puffs his pouch, brightens in color, and parades back and forth before her. They circle each other slowly and link tails. Whirling in unison, the couple then gambol across the seabed like prancing horses. Rising and falling, twirling and changing colors, they frolic together for up to half an hour.
Of course, the mating dance is a prelude to parenthood. “As the time to mate approaches, the sea-horse dance increases in length and frequency and can be repeated throughout the day,” says Kuiter. “As the dance reaches its climax, the couple slowly rise to the surface with tails interlocked and bodies close. The female then gently transfers her eggs to the male’s kangaroolike brood pouch.” The prospective father then finds a quiet spot to settle the eggs securely into the pouch lining. He fertilizes them and then begins the most unusual pregnancy in the animal kingdom.
“Every Woman’s Dream”
“I think it’s wonderful that sea-horse males get pregnant and have the babies,” said one woman. “They’re every woman’s dream,” quipped another. One male sea horse endured seven consecutive 21-day pregnancies in a single year!
As the baby sea horses lie nestled deep within the brood pouch, a rich network of blood vessels supplies them with oxygen and nutrients. Over time, the salinity within the pouch increases, thus preparing them for their future seawater home. When the time for birth arrives, the father’s labor may last from several hours to two days. Finally, his pouch opens, and the sea-horse babies are progressively ejected into the world. The number of babies born varies with the species but can range as high as 1,500.
Pets, Curios, and Remedies
Global pressures on sea-horse populations are increasing despite the fish’s high birthrate. Some authorities estimate that each year, 30 million sea horses are caught and traded worldwide. Many are destined for the traditional Asian medicine market, where they are used to treat a host of illnesses ranging from asthma and broken bones to impotence.
Every year about a million sea horses are used by the curio trade to make key chains, paperweights, and brooches. Trawl fishing, dynamite blasting of coral reefs, and pollution threaten the sensitive coastal areas where sea horses live. Sea horses are also caught in the wild for the aquarium trade—although few survive in captivity, since they require special food and are subject to disease.
To stem the tide, legal measures have been proposed that would require many nations to prove that their sea-horse exports are ecologically sustainable. Better methods and technologies are also helping a small number of commercial breeders to supply the aquarium market with sea horses bred in captivity.
The outlook for sea horses is tied in with the future of the oceans. “The world’s oceans are clearly under threat from human activity. We are taking too much of everything from them,” laments Kuiter. Will these dancing dainties of the sea be lost in the jarring symphony of human “progress”? “We have to be optimistic,” says Martin-Smith. “There is definitely goodwill out there among people. Our job is to make more people care about the earth’s living creatures. When that happens, change will occur. Perhaps if we can save the sea horses, we can also save the seas.” Perhaps. Happily, though, there is a more reliable source of hope.—Revelation 14:7.
[Picture on page 15]
Pygmy sea horse (actual size)
© Reinhard Dirscherl/Visuals Unlimited
[Pictures on page 16, 17]
Sea horses have the ability to transform their skin color dramatically to match their surroundings
Shorthead sea horse
Potbellied sea horses
Lined sea horse
[Picture on page 16]
High-crown sea horse
[Picture on page 17]
Shorthead sea horses
[Picture on page 17]
Male shorthead sea horse giving birth
[Picture on page 17]
Baby shorthead sea horses
[Picture Credit Lines on page 16]
Lined seahorse: © Ken Lucas/Visuals Unlimited; all other photos: Rudie H Kuiter
[Picture Credit Line on page 17]
All photos: Rudie H Kuiter