February 12, 2020

On Sunday, February 9, the 92nd Academy Awards—commonly known as the Oscars—were held at the Dolby Theatre in Hollywood, California. The Oscars celebrate the past year’s achievements in filmmaking. As happened in 2019, the award ceremony went without a host. Instead, the comedians Steve Martin and Chris Rock opened the show, and a variety of celebrities introduced and handed out the awards.

Parasite, which won best picture at the 2020 Academy Awards, stars (from left) Choi Woo Shik, Song Kang Ho, Chang Hyae Jin, and Park So Dam. Credit: CJ Entertainment

The biggest headline on Oscars night was the naming of the South Korean black comedy Parasite as best picture. Black comedy is characterized by bizarrely or morbidly humorous plots and situations. Directed by Bong Joon Ho, Parasite is the first movie in a language other than English to win best picture. Parasite also won best original screenplay and best international film. Bong too made history as the first South Korean to win best director. The World War I drama 1917—the favorite to win best picture before the ceremony—missed out on the top award but took home the best cinematography, best sound mixing, and best visual effects Oscars.

Renée Zellweger won the best actress award for her portrayal of the former Hollywood star Judy Garland in the biopic Judy. Joaquin Phoenix earned best actor for his leading role in the origin story of the Batman villain Joker. Brad Pitt won best supporting actor for his stuntman sidekick role in Once Upon a Time in Hollywood, and Laura Dern was named best supporting actress as a divorce lawyer in Marriage Story. Toy Story 4 won best animated feature, and American Factory won best documentary. American Factory, the story of a Chinese-run glass factory in Ohio, was the first film made by Higher Ground Productions, a company run by former United States President Barack Obama and former First Lady Michelle Obama. The World War II satire Jojo Rabbit earned the Oscar for best adapted screenplay.

Each trophy given out at the ceremony (there were a total of 24 this year) is officially called an Academy Award of Merit, but the small golden statues have been known as “Oscars” since the 1930′s. The origin of the nickname is uncertain, but most histories center on Margaret Herrick, a former director of the Academy of Motion Picture Arts and Sciences. Apparently, upon seeing the statuettes for the first time in 1931, Herrick remarked that they looked a lot like her Uncle Oscar. Oscar came into common usage for the award soon after.

October 10, 2016

The lamprey is an animal of contradictions. It looks like a leech, but it’s actually a fish. Some adult lampreys suck blood, but others don’t eat at all. Some kinds are invasive, but others are threatened. What is abundantly clear, however, is that the lamprey has a face only a mother could love.

Pucker up: the Lamprey says hello. Credit: © blickwinkel/Alamy Images

A lamprey is any of a group of fish with long, slender bodies and a round mouth with no jaws. Scientists consider the lamprey among the least developed vertebrates (animals with backbones) because it has maintained the same body plan for hundreds of millions of years. It has no bones; it instead has a flexible notochord made of rubbery tissue called cartilage running down the length of its back. A lamprey has fins on its back but not on its sides. A lamprey’s skin is smooth, shiny, and scaleless. All lampreys are dull colored, ranging from light tan to brownish- or bluish-black. They do not have true bony teeth. Their teeth are horny developments that grow from the inner surface of the mouth.

Different species (kinds) of lampreys live in lakes, rivers, and oceans. Ocean lampreys are the largest, growing as long as 3 feet (90 centimeters). Larval (young) lampreys have a significantly different diet than that of adults. They live in the sand and mud of stream bottoms for several years, filtering out tiny organisms from the water with their toothless mouths. Over time, they change into adults, developing eyes and teeth.

Adults of some lampreys are parasitic. They feed by attaching themselves to fishes, scraping a hole through the skin, and sucking out blood. An attacking lamprey buries its toothlike spikes in a fish’s flesh and forms a suction seal around the wound. Glands in the lamprey’s mouth secrete a substance that prevents the wound from clotting. After several hours, the lamprey detaches from its victim and swims away to digest its meal. The victimized fish is not killed, but it may die later from factors indirectly related to the wound. Harmful bacteria may colonize the wound and cause infection. Blood loss also weakens the fish, making it easy prey for predators.

Adults of other species of lampreys are more directly carnivorous (flesh-eating). Like a parasitic lamprey, a carnivorous lamprey swims up to a fish and latches onto it with its circular mouth. Rather than lap up blood, however, it eats through the fish’s flesh with its rasping tongue. The lamprey often gouges down to the bones, and the fish dies quickly.

The adults of a third group of lampreys do not eat at all. When they mature, their digestive organs degenerate, and they live only until the spawning season. After they spawn (reproduce), they die.

Habitat change brought about by humans has benefited some species of lampreys, while harming others. In the 1950’s and 1960’s, parasitic sea lampreys from the North Atlantic Ocean invaded the Great Lakes in central North America through locks and shipping canals. Fish species in the Great Lakes had not evolved (changed over time) in the presence of the lamprey, so they were more susceptible to the harmful effects of the lamprey’s parasitism. Over a few short years, fish populations of the Great Lakes plummeted to a fraction of their original level. Other species of lampreys, such as the nonparasitic American brook lamprey and the parasitic Pacific lamprey, are themselves threatened by habitat degradation from invasive species, shoreline development, and water pollution. Careful land and waterway management is needed to keep each species of lamprey healthy—and where it belongs.

July 18, 2016

It lives in your mouth, slicing your tongue with its razor-sharp jaws and sucking up blood. After your tongue withers away, it takes its place. You can only be thankful it stays, since you would slowly starve if it left. It is a tongue-eating louse, and, if fish could dream, it would haunt their nightmares.

An unlucky fish opens wide to display the tongue-eating louse. Credit: © Brian Saunders

The tongue-eating louse (Cymothoa exigua) is a parasitic marine isopod that infests the mouths and gill cavities of fish. A parasite is a living thing that feeds off another living thing, called a host. An isopod is a type of crustacean that commonly has seven pairs of legs. Tongue-eating lice are known to infest several kinds of fish, but their primary host is snapper.

Tongue-eating lice larvae swim into a fish’s gills and grow there, feeding on the animal’s blood, skin cells, and mucus. As they grow, the largest louse in the fish migrates into the fish’s mouth, anchoring itself with its strong legs. It then pierces the tongue with its sharp jaws and drinks the blood. Eventually, the tongue withers away because of a lack of blood. Rather than let its host die, the louse instead takes the place of the fish’s tongue, helping to hold prey in the fish’s mouth. The louse may continue to feed on blood or grab stray scraps of food, or it might not feed at all once it has reached full size. There are many species of isopods that parasitize fish, but Cymothoa exigua is the only one known to consume and replace a fish’s tongue.

All tongue-eating lice are born male. At some point during the process of destroying the tongue, the largest louse transforms to a female, and the smaller male lice mate with it. Researchers think the female only releases its larvae when the host fish is near other potential hosts, such as when fish swim in schools. Scientists are not sure what the female louse does after the next generation is sent out to infest more fish. Most marine isopods generally give birth to only one brood, so the female probably dies shortly after the larvae are released. Most marine biologists suspect that the fish slowly starves to death once its replacement tongue is gone, unable to effectively hold struggling prey in its mouth. It is possible, however, that another male living in the gills takes the female’s place (and sex), functionally becoming the fish’s new tongue.

Two things are certain. First, more work must be done to study this bizarre animal. Like other marine isopods, the tongue-eating louse infests several kinds of fish that people catch and eat. Consequently, it is important to understand the louse’s life cycle and any negative effects it has on its host. Second, we can thank our lucky stars the tongue-eating louse doesn’t infest humans!

December 14, 2015

Not feeling like yourself lately? It’s probably just a passing sensation. But if you are a mouse, you just might be under the influence of a mind-controlling parasite—Toxoplasma gondii.

Microscopic cysts containing Toxoplasma gondii develop in the tissues of many vertebrates. Here, in mouse brain tissue, thousands of resting parasites (stained red) are enveloped by a thin parasite cyst wall. Credit: Jitender P. Dubey, United States Department of Agriculture

A parasite is a creature that lives on or in another living thing, called the host, taking advantage of the host’s resources. T. gondii is a type of single-celled creature called a protozoan. It can live inside the body of a wide variety of warm-blooded animals, but a critical stage in its life cycle is only known to take place in felines. The creepy part is how the parasite spreads from cat to cat.

Cats get T. gondii mainly from eating rodents infected with the parasite. Rodents, such as mice, pick up the parasite from their environment. But T. gondii does not sit idle inside the rodent’s body, waiting for it to be picked off by a prowling feline. Instead, T. gondii somehow alters its host’s behavior. Normal rodents have an instinctive fear of felines—just a whiff of feline scent is generally enough to send a mouse scurrying for safety. But rodents with T. gondii show a decreased aversion to feline smells. This dampening of instinct makes it more likely that the rodent will engage in risky behavior, increasing the odds that it will be eaten by a cat and thus spread the parasite.

So much for the mouse, you might think. But we human beings love our cats—Westerners keep more cats as pets than any other animal. So it may not be too surprising that scientists estimate that one-third to one-half of all people may be chronically infected with T. gondii, which can lead to a disease called toxoplasmosis. Toxoplasmosis is rarely serious in healthy people. But the parasite remains in the body after symptoms pass, and scientists have begun to wonder whether the same mechanism that makes infected rodents fearless could also contribute to reckless behavior among people. One small study intriguingly suggests that people infected with T. gondii are more likely than others to be involved in traffic accidents.

Additional World Book articles:

• Pregnancy
• Friends Indeed: Pets and Your Health – A Special Report
• Infections Spread by Pets – A Special Report

Jan. 5, 2012

A previously unknown parasitic fly found in dead and dying honey bees in northern California may be a major culprit in a mysterious condition that has ravaged honey bee colonies in the United States. This condition, known as colony collapse disorder (CCD), was first detected in 2006, when beekeepers in the United States began reporting that large numbers of bees were mysteriously abandoning their hives. Studies revealed that the bees had died away from their hives. By 2012, CCD had been blamed in the deaths of millions of honey bees. Scientists have found evidence that pesticides, mites, a fungus, or a virus that causes honey bee wings to develop abnormally may be involved in CCD.

The parasitic fly, Apocephalus borealis, lays its eggs in the bees’ abdomen. Several days later, the infected bees fly from their hives at night. Scientists have found some of the infected bees still alive but in a zombie-like state. The insects were walking in circles, with no sense of direction, and soon become unable to stand up. Scientists aren’t sure whether the bees are leaving their hives under the control of the parasite or are being kicked out by their hive-mates, who may be sensing that something is wrong. Other parasites are known for their ability to control the behavior of the creatures they infest. The bees may also be leaving on their own to prevent their hive-mates from becoming infested. After the bees die, newly born fly larvae crawl from their neck. A. borealis also infects and kills bumble bees and paper wasps. Scientists believe it is very likely that the parasitic flies spread to honey bees from bumble bees.

A bee covered in pollen sips nectar from a flower. The bee will leave some of the yellow pollen grains at other flowers it visits, pollinating them. Many flowers rely on insects for pollination. © Steve Hopkin, Taxi/Getty Images

Bees are among the most useful of all insects. They pollinate many fruit and vegetable crops, which provide about a third of the human diet. In the United States, bees pollinate more than 130 crops, with a yearly value of $15 billion. These crops include apples, nuts, soybeans, and squash.

Additional World Book articles

• Back in Time (Biology 2007)
• Frisch, Karl von
• The Latest Buzz About Honey Bees (a Special Report)