Tuesday, March 30, 2010

Crayfish females lure males with urine

Releasing a steady stream of urine to attract a mate and then fighting off anyone who still dares to approach you doesn’t seem like a great idea for getting sex. But this bizarre strategy is all part of the mating ritual of the signal crayfish. A female’s urine, strange as it sounds, is a powerful aphrodisiac to a male.

Fiona Berry and Thomas Breithaupt studied these courtship chemicals by organising blind speed-dates between male and female crayfish, whose eyes had been covered with tape. They also injected a fluorescent dye into the animals’ bodies, which accumulated in their bladders. Every time they urinated, a plume of green dispersed through the water.

If the duo blocked the female’s nephropores (her urine-producing glands), the males never showed her any interest. If they met, they did so aggressively. But when the duo injected female urine into the water, things took a more lustful turn, and the males quickly seized the females in an amorous grip. Female urine is clearly a turn-on for males.

But the female doesn’t want just any male – she’s after the best, and she makes her suitors prove their mettle by besting her in a test of strength. As he draws near, she responds aggressively, even though it was her who attracted him in the first place. No quarter is given in these fights. The female only stops resisting if the male can flip her over so that he can deposit his sperm on her underside.

Female crayfish shoulder all the burden of raising the next generation, spending six long months rearing their offspring alone. Males, however, only contribute their sperm. Because the females make such a big investment in the next generation, it’s in their interest to choose the best partners.

Being nocturnal, they can’t see how strong a male is and chemical cues aren’t always reliable indicators of quality. The simplest way of discerning the strongest males is to test their strength for herself. By playing hard to get, she makes sure that she gets fertilised by the best mates, who will at least help to produce the fittest possible young even if they never help to raise them.

Urine typically has an aggressive meaning for crayfish. Males release it when they battle each other, and so do females. During courtship, the difference is that males are drawn to female urine and they stop releasing their own. Doing so might be their way of appeasing the violent female, his way of raising a chemical white flag in the hopes of getting a chance to mate.

In some ways, this is a surprising set-up. In species like crayfish, where females do all the work in raising the next generation, males usually have to be the persuasive ones during courtship while females are the choosy sex. But female crayfish have taken on both roles – seductress and selector. By sending out mixed messages with her urine, she can draw a pool of eager mates that she can then test.

Saturday, March 27, 2010

What Lies Beneath

What Lies Beneath


In Search of the Giants of the Sea

By Philip Hoare

Illustrated. 453 pp. Ecco/HarperCollins Publishers. $27.99

“Moby-Dick” is often viewed as a singularly American creation. Part of the beguiling genius of “The Whale,” a rhapsodic meditation on all things cetacean, is that Philip Hoare so suggestively explores the English origins of Herman Melville’s masterpiece while providing his own quirky, often revelatory take on the more familiar aspects of the novel. But “The Whale” is about much more than the literary sources of “Moby-Dick.” Always in the foreground of Hoare’s narrative is the whale itself, a creature that haunts and fascinates him as he travels to old whaling ports in both Britain and America, where he speaks with cetologists, naturalists, museum curators and former whalers on a quest to understand the whale, the cosmos and himself.

At least to the human eye, a sperm whale is a profoundly weird-looking animal, and Hoare makes the weirdness seem somehow familiar. The pale interior of the whale’s mouth “glows like a half-open fridge.” When the whale closes its mouth, the teeth of its lower jaw “fit,” Hoare informs us, “into its toothless upper mandible like pins in an electrical socket.” Hoare is always on the lookout for the revealing detail. When he visits the whaling mu­seum in New Bedford, Mass., he notices that the recently installed skeleton of a whale “incontinently . . . drips oil, like sap from a newly cut conifer.” He also has a finely tuned sense of perspective and pacing. As we read about how the six-man crew of a 19th-century whaleboat pursued its prey, we suddenly find ourselves under­water. “A mile below, the whale might be scooping up squid in the silent depths,” Hoare writes, “unaware of the danger that lurked above, the shapes that sculled over the ceiling of its world.”

Hoare is particularly insightful about Melville’s relationship with Nathaniel Hawthorne, the author whose influence turned what might have been, in Hoare’s words, “an exercise in propaganda for the American whaling industry” into “a warning to all mankind of its own evil.” It is a fascinating process to contemplate, how a 31-year-old former teacher and whaleman came to write a book “that saw into the future even as it looked into the past.” For a few brief months, Melville was in that unsustainable zone of miraculous creation, channeling a text that is as close to scripture as an American novelist is likely to write. “Each time I read it,” Hoare insists, “it is as if I am reading it for the first time.”

In one of the more entertaining episodes of “The Whale,” Hoare ventures to Cape Cod to trace Henry David Thoreau’s engagement with that region’s wave-battered coast. In Provincetown, he finds himself in a boat with the redoubtable and magnificently named Stormy Mayo, a Cape Codder who has devoted his life to studying and protecting the 350 to 400 remaining Atlantic right whales. Hoare describes how Mayo — wearing a hockey mask and a helmet equipped with a video camera — tries to untangle right whales from fishing nets. When Hoare finally sees a right whale for the first time, he is overwhelmed not by wonder but by the smell, which he describes as “somewhere between a cow’s fart and a fishy wharf.”

It is near the British whaling port of Hull in East Yorkshire, on the banks of the Humber River, that Hoare’s pilgrimage leads him to the “English Anchor” of “Moby-Dick.” In the great hall of the expansive manor house Burton Constable, Hoare comes face to face with “the only physical relics of Melville’s book”: pieces of the skeleton described by Thomas Beale in “The Natural History of the Sperm Whale.” Melville quoted relentlessly from Beale’s treatise, providing his own book with the factual ballast that kept it from being overwhelmed by its many literary influences, which in addition to Hawthorne included Shakespeare, Thomas Browne and a host of others.

Hoare provides a graphic account of whaling’s “historical crescendo” during the second half of the 20th century, when more than 72,000 whales were killed in a single year. Elsewhere he evokes a possible future in which the rising sea levels associated with global warming will allow the whale to become the planet’s dominant species “with only distant memories of the time when they were persecuted by beings whose greed proved to be their downfall.” As it turns out, whales have already ventured beyond this paltry ­planet. Unlike any other known substance, sperm whale oil works as a lubricant in the extra­ordinarily cold temperatures of outer space. “The Hubble space telescope is wheeling around the earth on spermaceti,” Hoare writes, “seeing six billion years into the past.” But that’s not all. The scientists who fitted out the Voyager probe decided that the song of the humpback was the best way to greet any possible aliens. This means that long after all of us are gone, the call of the whale will be traveling out into the distant reaches of the universe.

Hoare is to “The Whale” what Ishmael is to “Moby-Dick”: the genial, deceptively complex narrator who reveals only those personal details that are essential to his narrative. Since this is a book about deep divers, Hoare starts with an account of his near birth within a submarine. His parents had just begun a tour of a naval sub tied up to the docks in Portsmouth, England, when his very pregnant mother felt her first contraction. “For a moment,” Hoare writes, “it seemed as though I was about to appear below the waterline.” As it turned out, Hoare was born not beneath the waves but at his parents’ home in nearby Southampton, the famous port to which he returns near the conclusion of the book to discover that his mother is approaching the end. After a night on a cot beside her hospital bed, he awakens in the early morning just as she ceases to breathe, “leaving me,” he writes in an evocation of Ishmael’s fate in the epilogue of “Moby-Dick,” “another orphan.”

In the end Hoare plunges into the amniotic waters surrounding the Azores, where he sees his first living sperm whale. As he snorkels beside the huge creature he can feel its sonarlike clicks resonating through his body. “My rib cage had become a sound box,” he writes. “The whale was creating its own picture of me in its head; . . . an outline of an alien in its world.” Coupled with the recognition of his own inherent strangeness is the realization that this is a female sperm whale and that there is “an invisible umbilical between us.” And so “The Whale” finishes where it began, in the midst of a birth at the surface of a deep and mysterious sea.

Koalas catch Chlamydia

by Captain Skellett

Sitting up in their gumtrees, watching the world with little eyes set above the kind of nose you’d expect to find in a craft store. The koala’s fuzzy gray head is adorned with furry white ears, and the end result is a huge bundle of cute that makes you want to squeal.

Of course, being an Australian I know our cute koala isn’t as cuddly as it looks. Okay, it is when you actually get to cuddle one at the zoo. Otherwise they’re just plain vicious. Behind those fuzzy paws are some serious claws. They’re surprisingly fast on the ground, and they grunt in the night like a bush pig in a trap. Freaking terrifying to a twelve year old in a tent, let me tell you.

All the same I like koalas. They be fearsome.

Over a mug o’ rum this week, a friend told me an alarming tale about koalas. She said they catch Chlamydia because they are so promiscuous. It gives them a runny bottom, and makes them infertile.

I haven’t found much evidence that koalas sleep around. But they do have weird special sexual organs. Instead of having one head, a koala penis has two. The female has two internal vagina (vaginas?). The sciencey term for the double dippers is “bifurcated” and lots of marsupials are that way endowed. In fact the echidna penis has four heads!

As for Chlamydia, yes, koalas catch it. There are two strains which infect koalas. C. pneumoniae which humans can also catch, and is one of the leading causes of pneumonia in the world, and C. pecorum which some other animals get and causes urinary tract and respiratory infections. Although 40-70% of koalas test positive for Chlamydia, less than a quarter of them have symptoms at any one time. (Just to be complicated, the C in those names stands for Chlamydophila, a separate but very similar genus to Chlamydia. Same thing, different word says I.)

Chlamydia is a bacteria which acts like a virus. It has the usual cell wall, DNA, RNA, protein concoction that bacteria are so fond of, but unlike most bacteria it can’t grow by itself. To reproduce it has to hijack the machinery of another cell (like a human or koala cell). That’s how viruses roll.

It’s bad news for the koalas, as the cure for Chlamydia is a course of antibiotics taken daily – hard to do in the wild.

Wednesday, March 3, 2010

One Strange Fish Tale

By Peter Schmidt

Behold the regal rainbow trout, dappled denizen of deep lake and rushing river, fierce hunter of fish and fly—and prize of pork-barrel politics, invigorator of men, eradicator of native species, payload of numerous bombing missions.

An angler can catch a lot of rainbow trout and yet have no clue what a remarkable force of nature—and mankind—the creatures truly are. Anders Halverson, a research associate at the University of Colorado's Center of the American West, hoists them up for close inspection in a book just released by Yale University Press: An Entirely Synthetic Fish: How Rainbow Trout Beguiled America and Overran the World.

Few one-that-got-away stories sound nearly as improbable as his account of how our species, Homo sapiens, spread the fish species, Oncorhynchus mykiss, beyond its native range.

Consider that as of the 1870s, the rainbow trout and its sea-run variant, the steelhead, lived only along the Pacific Rim, from California to Russia's Kamchatka Peninsula. Since then, Halverson says, the fish "have been introduced to every state in the United States and to at least 80 different countries on every continent except Antarctica," an expansion of range that took humans, corn, sheep, and dogs thousands of years to achieve.

Halverson offers statistics that illustrate how much humans are still involved in the spread of rainbow trout: For each of the roughly four million people born in the United States each year, he says, state and federal hatcheries stock about 20 of the fish in public waters. Most of them being mature, they weigh a total of about 25 million pounds.
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Why make such an investment in spreading this one species of fish? It grows rapidly in hatcheries and withstands warmer waters and more-difficult conditions than other trout. Perhaps more important, Halverson says, the stocking of rainbow trout—which fight hard and leap acrobatically when hooked—has "satisfied a powerful human need": the primal urge to seek out and battle prey.

Halverson's book is a microhistory, an examination of America's involvement with a favored fish that sheds light on broader truths regarding our recent relationship with the natural world.

He says he fished for stocked rainbow trout while growing up in Colorado but eventually got bored with the pursuit and thought little of the fish until he became a graduate student in aquatic ecology at Yale University, where he earned his doctorate in 2005. At Yale "I came to realize there is a real paradox to the way so many fisheries are managed these days," he says. "Like most fishermen, I see fishing as a way to escape civilization and industrialization, and a way to sort of make peace with the natural world." Yet most rainbow trout, being either the products of hatcheries or the descendants of hatchery fish, "are in many ways a product of that industrialization."

He decided to write a book examining the artificial spread of the rainbow trout and obtained a National Science Foundation grant to help finance the undertaking. He initially expected the project to be mainly an exercise in muckraking (he had worked as a newspaper reporter before going to graduate school). But "the more people I met and the more people I interviewed," he says, "the more I realized what a complex topic this is." Although he came across case after case in which efforts to spread the trout led to environmental disasters, his book generally does not paint those involved as fools or villains.

When it comes to government policy regarding trout, he says, "there are a lot of issues for which there are no clear answers." He points to the dilemma posed by rainbow trout's ability to mate with the increasingly rare—and unhealthily inbred—cutthroat trout of the American West. Such interbreeding is causing cutthroats to become even rarer as a distinct species, but the purebred cutthroat population is having so much trouble surviving on its own that hybridization might represent the single best hope of passing the fish's genes along to future generations. It is unclear whether the long-term survival of cutthroats requires keeping rainbows at a distance or bringing the two species together.

The oddest specimens in An Entirely Synthetic Fish are the people. They include Livingston Stone, a New Hampshire pastor who abandoned the pulpit to raise brook trout on a fish farm, then ventured to California in the 1870s, initially to set up a federal salmon hatchery in the Sacramento River Valley. He encountered the rainbow trout and ended up propagating that species in a hatchery on the McCloud River, where he lived under threat of attack by outlaws and members of the Wintu tribe. In one report on his activities, he remarked, "With tarantulas, scorpions, rattlesnakes, Indians, panthers and threats of murder our course here is not wholly over a path of roses."

Among others described in Halverson's book is Al Reese, a crop duster and barnstormer who in the late 1940s helped persuade California's Department of Fish and Game to drop rainbow trout into mountain lakes from the air. (He tested the fishes' ability to survive the trip partly by holding live specimens out a car window at 70 miles per hour.) The state agency recruited World War II pilots and purchased surplus military airplanes to dump the fish, generally from about 200 feet. Many of the trout died on impact with the water or ended up stuck in trees, but enough survived to inspire the agency to similarly drop turkeys, partridges, and even beaver (in burlap sacks attached to parachutes). About 50 years later, the agency learned that it had gone overboard with its fish-bombing runs, inadvertently ridding lakes of rare frogs, which the fish had devoured, and filling some lakes with so many trout that their growth was stunted from too much competition for food.

California fish-and-game officials are hardly the only ones who eventually altered trout-stocking policies in response to evidence of money wasted or doing more harm than good.

The book devotes a chapter to the U.S. Fish and Wildlife Service's decision in 1962 to deliberately poison the Green River in Utah and Wyoming to wipe out the native fish and make room for rainbows. At the time, few in the agency questioned the idea of pouring huge amounts of the piscicide rotenone into a body of water. Since 1952 federal and state fisheries managers had used the chemical, which kills anything with gills, to clear the way for rainbow trout and other game fish in a long list of rivers and lakes around the nation, even within national parks.

A few scholars at Colorado State University and the University of Utah spoke out against the Green River plan and subsequently complained of efforts by state and federal agencies to shut them up by threatening to cut off grants to their institutions. Many of those involved in the river poisoning lived to regret it, for it ended up being a disaster for both the environment and public relations.

The project's planners assumed they would be able to keep the keep the river from carrying the rotenone into Dinosaur National Monument park by having workers neutralize the poison upstream from the park with potassium permanganate, but they were wrong. When dead fish turned up in the park, the Fish and Wildlife Service found itself in the cross hairs of the National Park Service. Perhaps even more important, about three weeks after the incident, Rachel Carson published Silent Spring, helping spawn an environmental movement that barraged officials in Washington with angry letters about the Green River kill.

The secretary of interior at the time, Stewart Udall, responded by curbing the use of rotenone by federal agencies and calling for the welfare of unique species to be a "dominant consideration" in such projects from then on. All four of the chief so-called trash fish that the Green River poisoning sought to kill—the humpback chub, the bonytail, the razorback sucker, and the Colorado pikeminnow—now have a place on the federal endangered-species list. The federal government has spent more than $100-million trying to save them.

An Entirely Synthetic Fish recounts many other governmental attempts at improving nature that went awry. In the 1960s, for example, researchers discovered that stocking a river with hatchery trout can decimate the wild trout population and actually leave it with fewer trout over all; the hatchery fish aggressively compete with the locals for food, and many end up being eaten themselves because they seem to associate the shadows of predators with those of hatchery workers tossing kibble. Beginning in the late 1980s, the Colorado Division of Wildlife inadvertently unleashed trout epidemics by stocking rivers with rainbows infected with parasite-born whirling disease, which leaves its victims disfigured and prone to swimming in tight circles.

The book also compellingly traces how the nation's attitudes toward fishing have varied over time. In the 17th century, the leaders of the Massachusetts Bay Colony regarded fishing with a hook and line as an exercise in idleness deserving punishment. During and just after the American Revolution, fishing suffered a similar image problem, thanks to its association with the English aristocracy. Beginning in the mid-1800s, however, interest in sport fishing boomed as it gained status as a diversion for the wealthy and came to be viewed as a pursuit that helped keep men virile and in touch with nature. Politicians eager to take credit for bringing hatchery jobs and better fishing to their states happily supported federal efforts to stock waters with game species.

Throughout much of America, one can still encounter the absurd sight of fishermen gathered on riverbanks next to hatchery trucks, hoping to catch naïve rainbow trout minutes after they are stocked. While not exactly shooting fish in a barrel, perhaps no other experience comes as close.

For his part, Halverson is attempting to restore the populations of rarer species of trout by, counterintuitively, encouraging people to fish for them. Taking a cue from the culture of birdwatchers, many of whom will travel long distances to add to their "life list" of species they have seen, he has set up a Web site that encourages anglers to catch and release as many species as they can. His logic is that if enough people roll into small towns and say they are out to hook rare fish species X or Y, the local chambers of commerce will get word, and new constituencies will be created to lobby for the fish's restoration.

Writing An Entirely Synthetic Fish has renewed his own interest in angling, both for rainbows and for other trout, Halverson says. "I actually love fishing again. You pick one of these rainbows up, and it is just a book that says so much about us."