Seeker Archives

Fish Converts Oyster Shell Into Speaker, Blasts Noise

In a pinch, oyster shells function as speakers for an industrious, communicative fish.

A clever fish has figured out that if it produces sounds in an oyster shell, the noises will carry over long distances, according to new research.

The study, published in The Journal of Experimental Biology, is just the latest to show that fish are far from being silent. Many can produce sounds by vibrating their swimbladders and, like a fishy form of Morse Code, they can create different meanings based on the sounds.

Fish-Eating Spiders Found Around the World: Photos

Pearlfish in waters off the remote Makemo Island atoll in French Polynesia take this to a whole other level. Researcher Loic Kéver of the University of Liège and colleagues discovered that the fish move into black-lip pearl oysters. Once inside the oysters, their vibrations substantially increase in volume.

"Amplification probably improves the efficiency of communication by increasing the propagation distance of the sounds," Kéver said in a summary of the report.

Kéver and his team collected some of the fish-containing oyster shells, which was no small matter in the bucolic, remote setting.

Video: Why Do Fish Come in So Many Colors?

"There is only one small scuba club, which means that we were always alone, except for a few locals," Kéver said with a smile. "There was limited infrastructure and electricity."

Back on land, the scientists determined that each sound made by the fish could last as long as three seconds, and consisted of 40 broadband pulses that were dominated by three frequencies: 212 Hz, 520 Hz and 787 Hz. Frequencies of around 1000 Hz were also amplified inside and out of the shells.

In other related news, researchers have found that oysters themselves communicate with each other by opening and closing their shells in response to different environmental conditions.

Tsuneo Honjo, director of the Seto Inland Sea Regional Research Center at Kagawa University, said some of the sounds are akin to shouting.

Fish Talk to One Another

Honjo explained that "we can hear the 'screams,' like 'we are in pain because of insufficient oxygen.'"

Not all of the sounds are so miserable, though. Honjo additionally said that pearl oysters tend to be more communicative than other oysters.

While he continues to study oysters, they seem to be faring well.

As Honjo said, "So far, oysters are talking in a healthy fashion."

Photo: Oyster shells. Credit: Pixabay

Animals have their own unique personalities, several recent studies have found, with many species showing certain characteristics more than others. As a result, some animals more closely mirror human personality traits, and even then, the match up depends on the particular person. Macho men, for example, have quite a lot in common with this male jumping spider. Machismo is usually connected to high testosterone levels. Lena Grinsted of Aarhus University’s Department of Bioscience told Discovery News that for spiders, the key behavior-related hormones appear to be octopamine and serotonin. Macho male spiders and tough females could very well be pumped up on a certain hormone, just as humans often are.

Spiders Have Personality Too

Are you a strong silent type? If so, you have this trait in common with many sparrows. Michael Beecher of the University of Washington and colleagues studied the birds and found that some are more effusive than others, at least when it comes to defending territories. The strong silent types defend their turf, but they don’t make a show of their intentions beforehand. "The strong silent types are just as assertive as the signaling types; they just don't advertise their aggressive intentions," Beecher told Discovery News. "You want to distinguish strong silent types from true wimps that don't signal and won't attack."

Video: Who's Your Daddy? Sparrow Gets Around

If you are more the shy type, you could commiserate with these three mouse lemurs, peering cautiously from their nesting tube at the Duke Lemur Center. Researchers there have found that mouse lemurs are definitely full of personality. At the center, mouse lemur Pesto is very chatty, researcher Sarah Zehr told Discovery News. "Asparagus gets beat up by the girls," she continued. "Wasabi is mean as sin, and her favorite flavor is human fingers." The three shy ones are too skittish to be so grouchy.

Parasite Brainwashes Mice to Not Fear Cats

If you consider yourself to be an empathetic person, then your animal personality match could be an Asian elephant. A study in the journal PeerJ found that when an Asian elephant detects that another is stressed out, it uses its trunk to gently caress the suffering elephant and emits a sweet-sounding chirp. "I've never heard that vocalization when elephants are alone," lead author Joshua Plotnik CEO of Think Elephants International and a lecturer at Mahidol University told Discovery News. "It may be a signal like, 'Shshhh, it's okay,' the sort of sounds a human adult might make to reassure a baby."

Elephants Added to List of Animals That Show Empathy

Some humans can wrap others around their fingers, while cats wrap themselves both literally and figuratively around their humans -- especially women. Cats attach to humans, and particularly women, as social partners, and it's not just for the sake of obtaining food, according to a study published in the journal Behavioral Processes. Cats sometimes even become a furry "child" in nurturing homes, crying out in a similar pitch and tone as a human baby would cry. Most owners know that if breakfast is late, the feline may make its presence known, usually in an affectionate way. Cats know what they want, and they often know how to get it too.

Cats Adore, Manipulate Women

Not all dogs are neurotic, but many are. The same holds true for humans. In fact, research published in the journal Interaction Studies found that neurotic men and neurotic dogs appear to be magnets for each other, with dogs of such owners making a beeline for their human partner and staying close together afterwards. The two might become co-dependent, but neither usually complains about it.

OCD Genes Found in Dogs

Abraham Lincoln famously said that democracy is, "government of the people, by the people and for the people," but the word "people" in that declaration easily could be replaced with other organisms, such as cockroaches. These sturdy insects govern themselves in a very simple democracy where each insect has equal standing and group consultations precede decisions that affect the entire group, according to a study published in the Proceedings of the National Academy of Sciences. If politics is your passion, you might have more in common with cockroaches than you might think.

Cockroaches: The Ultimate Survivors

Some animals -- including humans -- tolerate challenges better than others. Gigi Allianic, spokesperson for Seattle's Woodland Park Zoo, looked at how various species cope with rain. Orangutans wrap burlap bags around themselves, squirrels and mice huddle, while other animals simply retreat. Grizzly bears, on the other hand, usually remain out in the open and try to put up with the wet conditions. They "will often do that," she said, "even though they can go into an enclosure," Allianic said.

Photos: Peek in on a Bear in Surgery

Goldfish are so intelligent that they not only listen to music, but they can also distinguish one composer from another. A study, published in the journal Behavioral Processes, involved playing two pieces of classical music near goldfish in a tank. The pieces were Toccata and Fugue in D minor by Johann Sebastian Bach and The Rite of Spring by Igor Stravinsky. The goldfish had no trouble distinguishing the two composers. If you are brainy and musically inclined, goldfish might be your best personality match.

Goldfish Drives Own Motorized Aquarium Buggy

Peacocks are sexy, and they seem to know it. Male peacocks sing, strut their stuff, and dance in front of often blasé females who look a bit full of themselves too. The elaborate show draws attention, but not always from the right viewers. All of the dancing and prancing could alert potential predators that an easy meal is near. Wild peacocks make quick snacks for jackals, tigers and hawks in their native habitat in South Asia. "In a sense, they're advertising that they're distracted and vulnerable. It would be wise for a predator to capitalize on that," Duke University biologist Jessica Yorzinski told Discovery News. Many humans let down their guard for love too.