Mirror test hints at surprising cognitive abilities in fish

A fish called a cleaner wrasse interacts with its reflection in a mirror placed on the outside of the aquarium glass at a laboratory in Konstanz, Germany in this image released February 6, 2019. (REUTERS)
Updated 10 February 2019
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Mirror test hints at surprising cognitive abilities in fish

  • The test has been passed by great apes including chimpanzees, bonobos, gorillas and orangutans as well as dolphins, killer whales, an elephant and a magpie species, but failed by some other animals

WASHINGTON: A small tropical reef fish was able to recognize itself in a mirror, scientists said on Thursday in a finding that raises provocative questions about assessing self-awareness and cognitive abilities in animals.
The study involved experiments in which the fish species Labroides dimidiatus, called the bluestreak cleaner wrasse, was given a mirror self-recognition test, a technique developed in 1970 for gauging animal self-awareness.
In aquarium experiments at Osaka City University in Japan, the researchers applied a brown-colored mark on the fish’s body in a place that could be seen only in a mirror reflection.
The fish tried to remove the marks by scraping their bodies on hard surfaces after watching themselves in a mirror, but never tried to remove them without a mirror present, indicating they understood the reflection was of them, the researchers said. When a transparent, rather than brown, mark was applied, the fish never tried to remove it.
The four-inch-long (10-cm) species consumes parasites and dead tissue off skin of other reef fish in a relationship benefiting both. The brown mark’s color resembled the color of these parasites.
The fish “shows behaviors during the mirror test that are accepted as evidence for self-awareness in many other species,” said evolutionary biologist Alex Jordan of the Max Planck Institute for Ornithology in Germany, who led the study published in the journal PLOS Biology.
Jordan, however, questioned whether the test represents a reliable measure of animal cognitive abilities.
“I don’t claim that fish lack self-awareness, but rather that the minimal required explanation for the behaviors we observe in the mirror test does not require invocation of self-awareness, self-consciousness, or theory of mind,” Jordan said.
The test has been passed by great apes including chimpanzees, bonobos, gorillas and orangutans as well as dolphins, killer whales, an elephant and a magpie species, but failed by some other animals. Humans pass it at around 18 months old.
“I consider that there is a spectrum of animal consciousness, with some animals, likely primates, showing abilities closer to human consciousness,” Jordan said. “My point with this paper is not that fish are as smart as chimpanzees, but that the way we ask that very question across taxa (animal groups) needs to be re-evaluated.”
University at Albany evolutionary psychologist Gordon Gallup, who pioneered the mirror test, called the new study “not methodologically sound” and faulted the researchers for a “zeal to undermine the integrity” of the technique to appraise animal self-awareness.
Emory University primatologist Frans de Waal, who has studied mirror self-recognition in mammals, called the findings “interesting and provocative.”
“The hope is that this study will throw open the discussion about self-awareness in animals. Instead of the black-and-white distinction we have had thus far, that some animals have it and most of them don’t, we need to develop a more gradualist perspective,” de Waal said.


NASA probe detects likely ‘marsquake’ — an interplanetary first

A life-size model of the spaceship Insight, NASA's first robotic lander dedicated to studying the deep interior of Mars, is shown at Jet Propulsion Laboratory (JPL) in Pasadena, California, U.S. November 26, 2018. (REUTERS)
Updated 24 April 2019
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NASA probe detects likely ‘marsquake’ — an interplanetary first

  • A more distant quake would yield greater information about Mars’ interior because seismic waves would “penetrate deeper into the planet before they come back up to the seismometer,” he said

CALIFORNIA: NASA’s robotic probe InSight has detected and measured what scientists believe to be a “marsquake,” marking the first time a likely seismological tremor has been recorded on another planet, the Jet Propulsion Laboratory in California reported on Tuesday.
The breakthrough came nearly five months after InSight, the first spacecraft designed specifically to study the deep interior of a distant world, touched down on the surface of Mars to begin its two-year seismological mission on the red planet.
The faint rumble characterized by JPL scientists as a likely marsquake, roughly equal to a 2.5 magnitude earthquake, was recorded on April 6 — the lander’s 128th Martian day, or sol.
It was detected by InSight’s French-built seismometer, an instrument sensitive enough to measure a seismic wave just one-half the radius of a hydrogen atom.
“We’ve been collecting background noise up until now, but this first event officially kicks off a new field: Martian seismology,” InSight principal investigator Bruce Banerdt said in a news release.
Scientists are still examining the data to conclusively determine the precise cause of the signal, but the trembling appeared to have originated from inside the planet, as opposed to being caused by forces above the surface, such as wind.
“The high frequency level and broad band is very similar to what we get from a rupture process. So we are very confident that this is a marsquake,” Philippe Lognonné, a geophysics and planetary science professor at University Paris Diderot in France and lead researcher for InSight’s seismometer, said in an email.
Still, a tremor so faint in Southern California would be virtually lost among the dozens of small seismic crackles that occur there every day.
“Our informed guesswork is that this a very small event that’s relatively close, maybe from 50 to 100 kilometers away” from the lander, Banerdt told Reuters by telephone.
A more distant quake would yield greater information about Mars’ interior because seismic waves would “penetrate deeper into the planet before they come back up to the seismometer,” he said.
 
The size and duration of the marsquake also fit the profile of some of the thousands of moonquakes detected on the lunar surface between 1969 and 1977 by seismometers installed there by NASA’s Apollo missions, said Lori Glaze, planetary science division director at NASA headquarters in Washington.
The lunar and Martian surfaces are extremely quiet compared with Earth, which experiences constant low-level seismic noise from oceans and weather as well as quakes that occur along subterranean fault lines created by shifting tectonic plates in the planet’s crust.
Mars and the moon lack tectonic plates. Their seismic activity is instead driven by a cooling and contracting process that causes stress to build up and become strong enough to rupture the crust.
Three other apparent seismic signals were picked up by InSight on March 14, April 10 and April 11 but were even smaller and more ambiguous in origin, leaving scientists less certain they were actual marsquakes.
Lognonné said he expected InSight to eventually detect quakes 50 to 100 times larger than the April 6 tremor.