See the Sea Horses While You Can
These fabled fish and their cousins face a grim future
By Judith Kirkwood
Few creatures look more bizarre—or enchanting—than the sea horse, which appears to be assembled from the miniaturized spare parts of other animals. It possesses the flattened forehead of a horse, the shifty eyes of a lizard, the long snout of an aardvark, the armored plates of a stegosaur, the brood pouch of a kangaroo, and the prehensile tale of a monkey. No wonder many of the young children who visit the sea horses and their close cousins, sea dragons and pipefish, at the Audubon Aquarium of the Americas (www.auduboninstitute.org) in New Orleans imagine they have entered a magical world.
Ironically, the main message conveyed through the exhibit is that the world's wild sea horse population, which once flourished virtually everywhere, is at risk of vanishing. The World Conservation Union lists sea horses and their near relatives as endangered. In China, Indonesia, and the Philippines, millions of sea horses are ground up each year and used in traditional remedies for ailments ranging from sexual dysfunction to respiratory disorders. In addition, pollution, shoreline alteration, and destructive fishing methods continue to damage the coral reefs and sea-grass meadows in shallow coastal waters where sea horses live and breed.
|The sea dragon, a member of the same family as the sea horse, can grow to 17 inches and uses its leafy appendages as camouflage.|
Photograph courtesy of David bull/Audubon Aquarium of the Americas
The curious biology of sea horses makes them particularly vulnerable to disruptions in their environment, including temporary decreases in food supply and changes in water temperature. Sea horses typically grow from one to 10 inches high and weigh from a half ounce to five ounces. But they don't have stomachs for storing food in the short term and hence must eat almost continuously. A two-week-old sea horse can consume 3,600 baby shrimps in one day—up to 25 times its body weight. And raising sea horses in captivity poses an additional set of problems. "Getting them to eat properly is challenging," says Lance Ripley, an assistant curator at the Aquarium of the Americas. "Presentation is everything." The creatures are so sensitive to color and movement that often they won't eat unless their meal is placed directly in a water current so that their food stays in motion.
They are just as particular about their mating habits. After engaging in elaborate courtship rituals, some sea horses are thought to pair up for life. Couples greet each other every morning with a dance—lasting five minutes to four hours—complete with synchronized movements and dramatic changes in body color, then go their separate ways for the day. Procreation among sea horse couples is entirely unorthodox. The female deposits her eggs inside the male's brood pouch, where they are fertilized and then incubated for 10 days to six weeks (depending on the size of the species). Eventually, the male sea horse goes into labor, complete with birth pangs and writhing contortions. The sexual fidelity of certain sea horses may complicate their struggle for survival. If one member of a pair is fished or dies, the other partner stops reproducing, sometimes for several weeks.
Fortunately, the Aquarium of the Americas has had great success with the captive breeding of several sea horse species. This will provide an opportunity to study more closely the biology of sea horses in order to better protect them in their natural habitats. Visitors to the aquarium can peer into the aquarium's nurseries and see the newborn sea horses bobbing at the top of their tanks—a vision of hope. Toys Metamorphosis
Try viewing the world around you from a bug's perspective By Fenella Saunders Buzzerks
$9.95 each Insects: Little Creatures in a Big World
The Learning Team
Ever wonder what you'd see if you had eyes like a bug? If so, slip on a pair of Buzzerks (Insect Lore, $9.95 each, www. buzzerks.com
), toy glasses with prismatic lenses that roughly mimic a bug's-eye view. Peering at objects through Buzzerks, you see multiple images, an effect similar to looking through a kaleidoscope. These ersatz compound eyes offer only a crude approximation of insect vision. And to appear truly buglike, you'd need eyes that would rise up far beyond your forehead and wrap most of the way around your head. But Buzzerks will delight imaginative young bug lovers and playful adults who want to experience a partial metamorphosis. The eyeglass frames come in three styles—fire ant, hornet, or mantis—complete with perky antennae.
|Buzzerks's mantis bug glasses come equipped with flip-forward faceted lenses to help you see, look, and feel like an insect.|
Photograph courtesy of Buzzerks Eyewear
For more serious entomological insights, check out Insects: Little Creatures in a Big World
($49.95, The Learning Team, www.learningteam.com
), a CD-ROM that features videos, field recordings, and magnified images of 600 bugs in all their anatomic splendor. You'll discover that the compound eyes of an ant consist of 10 individual lenses, while a dragonfly has 10,000. That's because ants creeping along the ground need less visual acumen than flying bugs in search of pollen or prey. Each lens focuses on a very narrow portion of the insect's field of view; together they create a sort of low-resolution, mosaiclike image that is adequate for detecting the color of plants and the motion of prey or predators. More-refined eyesight would require optical equipment weighing more than the entire insect. A fly's large compound eyes, each made of 4,000 lenses, allow it to sense and respond to movement so quickly it's no wonder the critter is so pesky. Then again, once you've looked at things from a bug's point of view, you might think twice before you reach for that flyswatter. Books Wormhole Express
Hitch a ride into the past in four easy steps By Corey S. Powell How to Build a Time Machine
By Paul Davies
You've refinished the basement, brewed your own beer, even constructed a one-man ultralight aircraft, and still you feel unsatisfied. You need a real challenge. Paul Davies, a former physics professor at the University of Adelaide in Australia, has just the project for you: Try building a time machine.
Einstein established that a limited form of travel into the future is possible. According to the special theory of relativity, rapid motion or a strong gravitational field can noticeably slow the passage of time. If you set out in a very fast spaceship at 87 percent the speed of light—161,000 miles per second—you'll see time pass twice as quickly for the rest of the world as it does for you. Press on closer to the speed of light, and you can race ahead even more rapidly into the future.
Going into the past requires a great deal more work. But Davies approaches the problem with the can-do spirit of those old home-handyman guides. The key to backward time travel is a wormhole, which he compares to a "shortcut between two widely separated places." Scientists these days actually have promising ideas about how to create a wormhole on demand, and Davies describes the process step by step. First, use a particle collider to heat a speck of matter to 10 trillion degrees. Second, compress the resulting hot spot by a factor of a billion billion, making a wormhole (smaller than a subatomic particle) that connects two different regions of space. Third, blast the opening of the hole with a million one-terawatt laser beams until it's large enough for at least one passenger. Finally, whip one end of the wormhole around like a lasso at nearly the speed of light to create a time differential between the entrance and the exit. Now hop in, and you're on your way.
Like many instruction manuals, How to Build a Time Machine
isn't always easy to understand. The theory of time travel is inherently complex, and the book is quite short—just 128 pages, many of them illustrated—so ideas keep coming at a rapid pace. Davies is an old pro at this topic, and he does a commendable job of keeping the explanations simple. But considering the slightly tongue-in-cheek title of the book, the tone is oddly serious throughout. Many of the illustrations are cartoonish without being playful, and the final section on time-travel paradoxes is too solemn. What's the point of all this work if you can't have a little temporal fun? Books In the Name of Science
Do researchers have a right to inflict pain on lab animals? By Marc Bekoff Why Animal Experimentation Matters:
The Use of Animals in Medical Research
Edited by Ellen Frankel Paul and Jeffrey Paul
In a visitors lounge at a well-known research hospital, a team of medical scientists informs you that your ailing mother's chance of surviving her cancer would greatly increase if they could carry out a series of experiments. This scientific work might also benefit countless other victims of the same disease. The unwilling subjects of this groundbreaking research would be 10 chimpanzees, who, regrettably, would all be killed. Your consent is required. What would you do?
The decision would probably be a no-brainer for the authors of the essays in Why Animal Experimentation Matters: The Use of Animals in Medical Research,
all of whom support the use of lab animals. Nonhumans gain their moral significance only "by contributing to human welfare," argues H. Tristram Engelhardt Jr., a professor at Baylor College of Medicine. The rights, needs, and interests of humans, by definition, trump those of all other animals.
The authors, not surprisingly, take direct aim at the animal rights movement. But more telling is their reaction to dissent within the ranks of scientists. Jerrold Tannenbaum, a professor of veterinary medicine at the University of California at Davis, scoffs at researchers who believe that animals "are entitled not just to freedom from unnecessary or unjustifiable pain or distress but to well-being, pleasure, and even happy lives." By transforming lab animals "from research tools to friends," Tannenbaum contends, scientists risk calling into question the entire enterprise of animal research.
R. G. Frey, a philosopher at Bowling Green State University, takes a more circumspect view. He supports animal research but warns that the arguments in its favor lead into ethical quagmires. For example, he argues that chimps "give evidence of being more intelligent" than many "mentally subnormal humans, more sentient than anencephalic infants . . . and more able to direct their lives than humans in the final stages of Alzheimer's disease or senile dementia." Playing devil's advocate, Frey asks, If a human's life is "of lower quality" than an animal's, would it not be preferable from a moral standpoint to experiment on the human rather than on the animal?
Moral philosophy aside, the authors' most immediate concern is the increasing success of "abolitionists." A law proposed in the United States would give additional protections to tens of millions of rodents and birds used in federally funded research. Polls increasingly register the public's discomfort with inflicting pain on lab animals. And the number of animal subjects used in the United States is declining—a trend even more pronounced in Europe.
Nonetheless, at least 25 million animals (including chimpanzees, dogs, cats, rabbits, hamsters, birds, and rats) are used in U.S. research labs. What makes Why Animal Experimentation Matters
so disappointing, ultimately, is that it is far too one-sided. Nonanimal research alternatives, for instance, are summarily dismissed, despite much promising work in this area. Resolving a dispute so complex and emotionally charged as this one requires real dialogue between opposing camps. What's served up instead is an uncompromising, often arrogant polemic in defense of killing millions of animals for the benefit of humankind. Science Best-sellers
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Irwin M. Brodo, Sylvia Duran Sharnoff, and Stephen Sharnoff
Yale University Press, $69.95
The lichens commonly found on rocks and trees from the Arctic to the tropics are surprisingly complex organisms, symbiotically composed of a fungus and either bacteria or algae—and sometimes all three. This encyclopedic volume overflows with gorgeous color photos, range maps, and habitat information that document the astounding diversity and beauty of more than 1,500 species. Faith, Madness, and Spontaneous Human Combustion:
What Immunology Can Teach Us About Self-Perception
Gerald N. Callahan
Thomas Dunne Books (St. Martin's Press), $23.95
Callahan, a poet and immunologist, proposes that the human immune system—which remembers organisms and diseases we've fought off by literally storing little pieces of them—forges our individual identities as much as the memories we form in our minds. Drawing poignantly on the stories of people in his own life, Callahan contends that experiences as complex as love and madness are intricately bound up with our immunologic makeup. The Atoms of Language:
The Mind's Hidden Rules of Grammar
Mark C. Baker
Basic Books, $28
Are the world's 6,000 languages fundamentally different from one another, or do they share a common underlying structure? Baker, a cognitive scientist, argues that most, if not all, languages conform to a common set of rules. Mapping these rules, says Baker, could produce a periodic table of language, a single framework from which all tongues are derived. Time Traveler:
In Search of Dinosaurs and Other Fossils From Montana to Mongolia
Farrar, Straus & Giroux, $26
Novacek, the curator of paleontology at the American Museum of Natural History, is an intrepid scholar whose fossil-hunting expeditions have taken him to remote parts of the world, from the tips of the Andes Mountains to the vast dunes of the Gobi Desert. Some of the adventures he recounts in this memoir involve perils worthy of Indiana Jones.
— Maia Weinstock
For more information about sea horses and their cousins, see the Web page of Project Seahorse: www.seahorse.mcgill.ca
For vivid pictures and fascinating facts about pipefish, see www.seahorses.de/ pipefish.htm
Marc Bekoff and Jane Goodall cofounded the Ethologists for the Ethical Treatment of Animals/Citizens for Responsible Animal Behavior Studies: www.ethologicalethics.org
For a herd of animal research-related links, see the Humane Society Web site at www.hsus.org/programs/research/ links.html#top
Glimpse the world through a honeybee's eyes at cvs.anu.edu.au/andy/ beye/beyehome.html
To take a closer look at fly eyes, download www.zoo.cam.ac.uk/zoostaff/laughlin/nfis 2000/fly_eye.pdf