Animal Tales: Seahorses really are fish

By ALEX CUKAN, United Press International

Few sea creatures generate as much affection from the public as seahorses, which often comprise an aquarium's most popular exhibit, but although it adorns many a shower curtain, most people do not realize it is a fish.

"Seahorses have a mystical quality -- they don't look like anything else from the sea," Jeff Boehm, vice president for conservation and veterinary services at the Shedd Aquarium, in Chicago, told UPI's Animal Tales. "They have the unusual property of the male getting pregnant and giving birth and they're just beautiful animals," he added.


Although the seahorse has a fish's gills and fins, it has no scales. Instead it has bony plates made of flexible minerals. It resembles a horse more than a fish, but its tail can grip coral or anything else small enough to grasp as it waits for its prey of shrimp, small crustaceans and other tiny creatures able to fit in its funnel-like mouth.


The 33 different species of seahorses are found in temperate shallow water as far north as Nova Scotia in Canada or as far south as Argentina.

There are 16 species of seahorse in the current exhibit on seahorses, pipefish and sea dragons at the National Aquarium in Baltimore. Pipefish are related to seahorses but "don't have their tails curled like the seahorse so they can look a piece of grass," explained Jim Anderson, the aquarium's seahorse program manager.

"The seahorse varies in size from one inch to 12 inches and the sea dragons can be 16 inches -- they are ornate and they look like something out of 'Dr. Seuss,'" Anderson said.

The seahorse display, open until the end of the year, is the most popular exhibit at the National Aquarium, outscoring the dolphins, according to Anderson. The aquarium also has a seahorse breeding lab where research on their behavior and breeding is done in collaboration with its conservation program, he said.

According to Sara Lourie, a doctoral student at McGill University in Montreal, seahorses also have a bit of romance.

"They're loyal, they mate for life and if one is taken away by fishing or a predator -- although man is their biggest predator -- the other will most likely not mate again," Lourie told UPI. "They are also site faithful, most of the seahorses studied maintain a home range of one small area all within a few square meters -- some live in areas with strong currents and use their tail grasp something to keep from being moved away."


The female produces eggs and deposits them in the male's pouch, which is similar to a kangaroo's. Once fertilized the eggs develop inside the pouch and are born within 10 days to three weeks, Lourie said, adding, "the babies are fully developed when born and the parents give them no more care."

Lourie discovered a new species while studying pictures of seahorses.

"I was looking at photographs and working to classify different seahorses and there was one I didn't recognize," she explained. "While working on my Ph.D., in Indonesia, I was fortunate to get to go on a diving boat and using scuba equipment I was able to get specimens from 15 meters deep."

The new species is the smallest on record and a rival to the world's smallest fishes and is known as the pygmy seahorse.

"Adults of the new species, a pygmy seahorse or Hippocampus denise, are typically just 16 millimeters long -- about the size of a fingernail," Lourie said. "In the past they have been mistaken for the offspring of seahorses."

The size and other distinguishing traits of H. denise could help scientists understand the constraints of a small fish.

Lourie and John Randall of the Bishop Museum in Honolulu, Hawaii, describe the new species in the current issue of the journal Zoological Studies.


As the scientist chiefly responsible for the find, Lourie had the honor of naming the new species. She chose to recognize underwater photographer Denise Tackett, whose 1997 images first hinted at the need for a new seahorse classification.

"Denise" is derived from Dionysus, the Greek god of wine, and means "wild or frenzied," which seems appropriate, Lourie explained.

"Compared with other small seahorses, they're active little creatures," she continued. "Because it lives among the deeper corals and is a master of camouflage, the diminutive new fish is probably safe from the over-exploitation threatening other seahorse species. But with only a handful of sightings on record, it's hard to know what risks they face."

Lourie works with Project Seahorse, based in Vancouver, British Columbia, an international marine conservation team that conducts research, establishes marine protected areas, manages subsistence fisheries, restructures international trade, advances environmental education and redresses habitat loss.

According to the Project Seahorse team, 20 million seahorses are take from the oceans each year.

"They are mostly taken for home aquariums and for traditional medicine in Asia where many believe they are an aphrodisiac, a cure for male baldness and a host of other things," Lourie said. "Heavy-duty trawling gear that can flatten reefs is another potential threat, (as is) underwater tourism -- divers and photographers (who) could possibly love these animals to death."


One the aquarium's messages is "keeping a seahorse as a pet ... is a difficult proposition and we discourage it. There's a lot to know about its food, husbandry and ecosystem," Boehm said.

"There are some home hobbyists who are very skilled and can maintain seahorses but they are in a minority," he cautioned. "It's a pretty small planet and what we try to explain at the aquarium, for many people who have never seen the ocean, is that our actions ... have an impact on the sea life."

Boehm said if the aquarium's efforts can cause people to become excited about the fate of the seahorse, "we hope they will look at what they can do in their day-to-day life -- from the fish they eat to the car they drive -- to conserve the oceans and the ecosystem."

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