National Geographic : 1959 Jan
The sea horse has a colt's like body, and the pouch of is a fish. Moreover, the male head, an insect's shell a kangaroo, yet actually gives birth to the young. Little Horses of the Sea By PAUL A. ZAHL, Ph.D., Senior Editorial Staff (Natural Sciences), National Geographic Magazine With photographs by the author ONE winter morning the kindergarten teacher in a New York City school for boys gathered her brood for a conversation period. Peter spoke profoundly on the subject of scooters; Jim, about his col lection of plastic soldiers; Tom, of the sailboat pond in Central Park. When it was our son Paul's turn, he an nounced that he would talk about sea horses, on which he considered himself something of a specialist. He had recently watched me set up, in our apartment, salt-water aquariums stocked with pygmy sea horses, whose more normal habitat is the grassy inlets and shallow bays of warm seas. Our success had been considerable: Our horses frolicked contentedly in their aquatic corrals, feeding with gusto on the brine shrimp we provided, and giving birth in due course as though in the privacy of their natural environment. The teacher nodded approval as young Paul began: "Yesterday I watched a sea horse give birth to many babies. I saw the babies come out of the father's stomach." The teacher reddened slightly and inter rupted to say: "Paul, I think you mean a mother sea horse." "No," insisted the youthful ichthyologist, "the father had the babies." A patient smile played over the teacher's face as Paul, with quiet confidence, told how he and his sister Eda, age 9, had the night before watched a male sea horse delivering. One by one, the babies had come out of the "stomach," usually tailfirst. Quickly they had gained confidence and propelled themselves off in search of a blade of grass about which to twine their tails. Whether Paul convinced the teacher, I do not know. Next day in the faculty lounge, however, her story caused some chuckling. As she confessed subsequently to my wife, she was inspired to check Paul's story in an en cyclopedia. There it was in black and white-the facts of a strange life cycle in which the female sea horse deposits her eggs directly into the male's brood pouch. Here they are fertilized and developed, to be live-born after a hatch ing period of about 10 days. Stable in an Apartment Converting our apartment into a sea horse stable was more than a whim. In earlier years we had kept a home menagerie of animal pets, including many fresh-water tropical fish.* Then, like many home aquariists, we discov ered that certain marine species may be maintained almost as easily as their fresh water cousins; it is now possible to get salts and concentrates which produce a solution closely resembling pure sea water. For the beginning salt-water aquariist, the pygmy sea horse (Hippocampus zosterae, a member of the fish group) is ideal, not only because the species is hardy, but because it is one of the most delightful miniatures in the whole aquatic world. Our first shipment of sea horses arrived one * See "In the Wilds of a City Parlor," by Paul A. Zahl, NATIONAL GEOGRAPHIC MAGAZINE, Nov., 1954. Pygmy Sea Horse Tethers Tail to a Giant Cousin's and Mimics His Repose Spangled with silver and gleaming with galaxies of white dots, six-inch-long Hippo campus hudsonius arches his neck like a thoroughbred as he sways atop a sea whip in the author's aquarium. Smaller, less colorful H. zosterae clings to the tapered body; another pygmy perches at lower left. The two species live compatibly in Florida waters. KODACHROMESBY PAUL A. ZAHL, NATIONALGEOGRAPHICSTAFF © N.G.S.