As scientists discovered many decades ago, the male seahorse is the one that becomes pregnant, carries the young in his belly and gives birth. It was Dr. Amanda Vincent of Oxford University’s department of zoology in Canada which discovered the unique mating and reproduction process of the seahorse.
According to Dr. Vincent, the reproductive cycle starts when the female seahorse deposits 100 or more eggs into the pouch of the male’s abdomen. The male releases sperm into the pouch, fertilizing the eggs. The embryos develop within the male’s pouch, nourished by their individual yolk sacs. Incubation may last two to six weeks, depending on the seahorse species. After the embryos have developed, the male gives birth to tiny seahorses about one centimeter long.
Seahorses are generally monogamous, though several species are highly gregarious. In monogamous pairs, the male and female will greet one another with courtship displays in the morning and sometimes in the evening to reinforce their pair bond. They spend the rest of the day separate from each other hunting for food.
Seahorses are small saltwater fish belonging to the Syngnathidae family, which also includes pipefish and sea dragons. The seahorse’s scientific genus name, Hippocampus is a Greek word, which means “bent horse.”
Seahorses range in length from about 2 inches to 14 inches. Known for their small compressed body covered with 50 rectangular body plates, they also vary in colors - white, yellow, red, brown, black, gray, spotted or banded. The tail is prehensile, and the tubular mouth sucks in small shellfish, shrimp, larvae and small crustaceans as food. The head and foreparts, usually carried upright, resemble those of a horse. They swim vertically and beat their fins up to 70 times a second.
Seahorse figures prominently in some cultures around the world. In Mexico, for instance, there is a legend which stated that the seahorse is a person who, to escape his pursuers, fled into the sea, placing his sandals in his waist belt at his back. In Hawaiian culture, the seahorse has long been a sign of eternal friendship. The National Society for Epilepsy has a seahorse for its mascot (because a part of the brain that is vulnerable to damage from epileptic seizures resembles a seahorse in shape). Tatsunoko Production, the Japanese anime company, has a seahorse in its logo.
Seahorses have been associated with mythology. The Chinese believe that seahorses have magical or medicinal effects. They are used for the treatment of respiratory disorders, throat infections, arteriosclerosis, kidney disease, goiter, lymph disorders, skin diseases, lethargy, infertility and sexual impotence. It was also reported to be a potent aphrodisiac that has been used by the Chinese and other Orientals, centuries before the controversial Viagra.
In Australia and the surrounding countries, seahorses are used for tourist merchandise, such as key chains and souvenirs.
There has also been strong demand for live seahorses. Unlike in traditional Chinese medicine, where large, smooth-skinned seahorses are preferred, the live trade is mostly in smaller seahorses, which fit more easily in home aquariums. And since home aquarium enthusiasts are usually not picky about whether the seahorses are smooth- or spiny-skinned, there is a market for nearly all seahorses, large or small, smooth or spiny.
“While many aquarium hobbyists will keep seahorses as pets, seahorses collected from the wild tend to fare poorly in a home aquarium,” cautions an expert. “They will eat only live foods such as brine shrimp and are prone to stress in an aquarium, which lowers the efficiency of their immune systems and makes them susceptible to disease.”
But despite this, the exploitation of seahorses for international trade is very serious. Aside from China and Australia, countries that are involved in buying and selling seahorses include Belize, Brazil, Ecuador, Hong Kong, India, Indonesia, Italy, Japan, Kuwait, Malaysia, Mexico, New Zealand, Pakistan, the Philippines, Singapore, Spain, Sri Lanka, Tanzania, Taiwan, Thailand, United Arab Emirates, the United States, and Vietnam.
The largest known importers are China, Hong Kong, and Taiwan. In 1992 alone, China consumed roughly 20 tons of seahorses. Among the largest exporter is the Philippines, where about 70 percent of seahorses disappeared as a result of massive fishing in the past 10 years.
Trade is not the only problem seahorses are facing. They are also battling the gradual loss of their habitat. The seahorses are found in most coastal areas which have sea grass beds, mangroves, or coral reefs. Most of these habitats are destroyed through the pollution of coastal waters, felling of mangrove forests, dredging and draining of sea grass beds and destruction of reefs by cyanide and dynamite fishing.
According to some studies, the loss of the seahorses from their natural habitat could disrupt the delicately balanced ecosystem. The main meal for the seahorses is shrimp, which they after gather as the swing by their tails from blades of seagrasses. Despite their ability to change their color to match their surroundings, seahorses are often meals for penguins and crabs. Their bony exterior, however, discourages most fish. The other natural enemy of the seahorse is the weather. Often a storm may cast seahorses adrift and they die of exhaustion.
Dr. Vincent, who is considered the foremost authority on international seahorse trafficking, reported the seahorse population worldwide has likely plummeted 50 percent since the beginning of the 1990s.
“The threats are great to seahorses around the world,” deplored Dr. Vincent, who believed the international seahorse trade is worth US$40 million. “We need to put the brakes on how, before there’s a catastrophic collapse.”
No one knows how many seahorses exist in the wild, but more than 120 species names have been proposed for seahorses over the past 200 years, although many have turned out to be synonyms for the same species.
While nobody knows how many seahorses swim the world’s waters, they have been overfished, forcing the World Conservation Union to list 32 seahorse species as “threatened.” An estimated 20 million seahorses are taken from the wild each year, according to Project Seahorse.
Among the more populated areas for seahorses are southern Australia and Tasmania, China, and the Philippines. “Being archipelagic, the Philippines has one of the most diverse reef fish fauna in the world,” says Dr. Rafael D. Guerrero III, the former executive director of Philippine Council for Aquatic and Marine Research and Development. “As such, it provides a rich supply for the marine ornamental or aquarium fish trade including the seahorse which is among the most popular ornamental fishes.”
In the Philippines, scientists have found at least eight species of seahorses. In 2004, the ban on taking seahorses was imposed in the country.