Sea horses spur further discussion

ABOUT LAST week's column regarding my visit to the Kona sea horse farm (May 18), a friend said, "It was interesting, but it left me with a lot of questions."

I knew that would happen, because to tell the story of the farm, I had to skip the story of the fish. And it's a good one. How many fish have horse heads, monkey tails, pregnant males and possess, as some believe, magical medicinal powers? Only the little sea horse has it all.

The scientific name for sea horses is Hippocampus. In Greek, "hippo" means horse and "campus" means sea monster. It's hard to fathom why anyone would call these cute little fish monsters, but ancient Greeks considered sea horses freaks.

In 1810 an Italian naturalist suggested that sea horses were insects. This isn't as off the wall as it sounds. A series of hard body rings encase sea horse bodies, giving the impression of an external skeleton.

These animals also lack teeth and can move their eyes independently, like chameleons.

But in spite of their unusual looks, sea horses are true fish, with backbones, gills and fins.

Unlike other fish, though, sea horses have tails that can wrap around seaweed and other stationary objects on the ocean floor. This anchors these weak swimmers, which otherwise are at the mercy of currents.

Hanging onto a blade of sea grass also helps the fish hide. Sea horses grow skin flaps and change colors to blend in with their surroundings. Color changing is also an important part of mating.

Sea horses are monogamous, a rare occurrence on coral reefs.

Each morning, a mated male and female find each other and perform a greeting of dancing and color changes. Such behavior lets the other know when the time is right for mating. When it is, the pair link their tails, and the female deposits her eggs into the male's belly pouch. Fertilization occurs inside his pouch.

After 10 to 21 days, the male gives birth to up to 150 babies. These miniature sea horses rise immediately to the surface to take a gulp of air, which helps them stay upright.

The world's oceans host about 35 sea horse species. Because of the fishes' color and skin changes, this number is debatable.

Habitat destruction, pollution and collecting for aquariums threaten sea horse survival. The big hit, though, comes from traditional Chinese, Japanese and Korean medicine, whose practitioners use dried sea horses to treat asthma, atherosclerosis, thyroid disorders, skin diseases, heart disease, sexual dysfunction, lethargy and pain.

Education and aquaculture are two good answers to sea horse exploitation. The Big Island sea horse farm I visited (www.seahorse.com) is successfully doing both.

Biologists there raise one hardy Atlantic species to sell. To prevent this non-native from getting into Hawaii's waters and competing with our three native sea horse species, the farm does not sell its sea horses here. Workers are experimenting with raising Hawaii sea horses for Hawaii residents.

As we left that farm two weeks ago, Craig said to me, "That one-hour tour gave you material for about 10 columns." He was right because in this, my second one, I answered only one of my friend's five e-mailed questions.

Oh, well. I have eight more columns to go.

Marine science writer Susan Scott can be reached at www.susanscott.net.