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Freshwater Fish Can Do Math, New Study Suggests

A researcher from University of California, Davis catches hatchery salmon from a tank to measure their size, as part of a joint project between ecologists and rice farmers trying to reclaim the great flood plains of the Sacramento River for salmon habitat, in Robbins, California, US, February 4, 2022. REUTERS/Carlos Barria
A researcher from University of California, Davis catches hatchery salmon from a tank to measure their size, as part of a joint project between ecologists and rice farmers trying to reclaim the great flood plains of the Sacramento River for salmon habitat, in Robbins, California, US, February 4, 2022. REUTERS/Carlos Barria
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Freshwater Fish Can Do Math, New Study Suggests

A researcher from University of California, Davis catches hatchery salmon from a tank to measure their size, as part of a joint project between ecologists and rice farmers trying to reclaim the great flood plains of the Sacramento River for salmon habitat, in Robbins, California, US, February 4, 2022. REUTERS/Carlos Barria
A researcher from University of California, Davis catches hatchery salmon from a tank to measure their size, as part of a joint project between ecologists and rice farmers trying to reclaim the great flood plains of the Sacramento River for salmon habitat, in Robbins, California, US, February 4, 2022. REUTERS/Carlos Barria

Some primates, bees, birds, and now freshwater fish: the circle of animals with mathematical skills is widening. A recent study has found that some types of fish have mathematical abilities such as addition.

It’s scientifically proven that all vertebrates, and even some invertebrates have the ability to measure quantities- a vital function creatures need when searching for food, avoiding predators, moving in group, and mating.

But scientists are now investigating how these creatures can quantify: is it a simple estimate based of the object’s size, or they are actually able of doing accurate math? Former studies showed that some monkeys, parrots, pigeons, spiders, and bees are capable of processing numerical information, and even performing simple mathematical functions.

A recent study at the University of Bonn’s Institute of Zoology revealed that some types of fish such as cichlids, stingrays, and zebra mbuna have some math skills. The findings were published in the journal Scientific Reports.

Eight fish of each type underwent hundreds of tests in large tanks specially designed to monitor their performance. In the tanks, the fish were trained to associate the blue color with addition (+1), and the yellow color with subtraction (-1).

Then, the scientists spread cards featuring blue and yellow shapes, and made the fish choose from two sliding doors each featuring a card with different number of shapes; one of the two doors has the correct answer.

For instance, when a fish sees a card with three blue shapes, it is supposed to swim towards the door with the card featuring four blue shapes as blue refers to addition. On the contrary, if the fish sees a card featuring four yellow shapes, it should head towards the door with the card featuring three yellow shapes, one shape lesser than the original card, as yellow refers to subtraction.

When the fish passed through the correct door, it was rewarded with its favorite food. The study showed that six of the mbuna fish and four stingrays successfully linked blue to (+1), and yellow to (-1).

According to researchers, the mbuna fish needed more time to select the door, and mbunas and stingrays remembered addition more easily than subtraction.

The researchers said their work unveils new cognitive abilities that could help mbunas and stingrays recognize other fishes from the same species based on their appearance, by counting the lines or spots on their bodies.

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Why Does Trump Want to End US Daylight Saving Time?

Members of the public on a snow covered National Mall in Washington, DC, USA, 06 January 2025. (EPA)
Members of the public on a snow covered National Mall in Washington, DC, USA, 06 January 2025. (EPA)
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Why Does Trump Want to End US Daylight Saving Time?

Members of the public on a snow covered National Mall in Washington, DC, USA, 06 January 2025. (EPA)
Members of the public on a snow covered National Mall in Washington, DC, USA, 06 January 2025. (EPA)

Daylight saving time, a practice affecting almost 400 million people across North America, is once again in the spotlight as debates over its necessity continue. This twice-a-year ritual of adjusting clocks forward in spring and back in autumn has been ingrained in American, Canadian and Cuban life for more than a century. However, US President-elect Donald Trump has pushed for an end to daylight saving time, which he has called inconvenient and costly.

WHAT DID TRUMP SAY ABOUT DAYLIGHT SAVING TIME?

Trump said his Republican Party would work to end daylight saving time after he takes office on Jan. 20.

"The Republican Party will use its best efforts to eliminate Daylight Saving Time, which has a small but strong constituency, but shouldn't!" Trump wrote on social media. "Daylight Saving Time is inconvenient, and very costly to our Nation."

Trump's billionaire allies Elon Musk and Vivek Ramaswamy, whom he picked to lead a new Department of Government Efficiency, have endorsed Trump's plan.

In 2022, the US Senate passed a bill called the Sunshine Protection Act that would make daylight saving time permanent. It stalled in the House of Representatives because lawmakers could not agree on whether to keep standard time or permanent daylight saving time.

Republicans, who control both chambers of Congress, could revive the bill or introduce a new one.

WHEN DO THE CLOCKS CHANGE?

Any changes that Trump and the Republicans may enact probably would not take effect immediately.

Daylight saving time in the United States and some other countries is due to start on March 9 at 2 a.m. local time, meaning people will lose an hour of sleep. Mornings will be darker but it will stay light until later in the evening. Daylight saving time is scheduled to end on Nov. 2. The saying "spring forward, fall back" serves as a helpful reminder for adjusting clocks.

Daylight saving time in the United States always starts on the second Sunday in March and ends on the first Sunday in November.

In the UK and other European countries, daylight saving time, also known as summer time, begins on the last Sunday in March and ends on the last Sunday in October. This year it will start on March 30 and end on Oct. 26.

WHEN IS THE SHORTEST DAY OF THE YEAR IN 2025?

The shortest day of 2025 will be on Dec. 21, which marks the winter solstice. Daylight hours vary significantly across latitudes in the Northern Hemisphere. Areas near the North Pole will be plunged into complete darkness while southern regions will still get more than 10 hours of sunshine.

WHY WAS DAYLIGHT SAVING CREATED IN THE US AND HOW DID IT START?

The modern idea of changing the clocks with the seasons can be traced back to at least the late 19th century, when New Zealand entomologist George Hudson proposed it to conserve energy and extend summer daylight hours, something that would have benefited his hobby of collecting insects after work. The idea was slow to gain traction until World War One, when European states sought any strategies to conserve fuel. Germany was the first country to adopt daylight saving time in 1916. The United States followed in 1918.

The practice went through many variations before the United States standardized it in 1966 in a law called the Uniform Time Act, which allows states to opt out of it but not to stay on daylight saving time permanently.

WHY IS DAYLIGHT SAVING TIME CONTROVERSIAL?

A common myth is that the United States adopted daylight saving time to benefit farmers, but in reality many farmers are opposed to the practice for being disruptive to their schedules.

The original motivation to conserve fuel is also under debate, as studies have found little, if any, energy savings from the shift, according to the US Congressional Research Service.

Opponents point to other studies that have found adverse health effects linked to daylight saving time, such as a spike in fatal traffic accidents, heart attacks, strokes and sleep deprivation in the days after clocks are moved forward an hour every March.

A March 2023 YouGov poll found that 62% of Americans want to end the practice of changing clocks, though only 50% prefer to keep permanent daylight saving time.

DO ALL US STATES OBSERVE DAYLIGHT SAVING TIME?

No. Hawaii and Arizona, with the exception of its Navajo Nation region, do not observe daylight saving time. The US territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the US Virgin Islands also observe permanent standard time.

While daylight saving time is widespread across the United States, 19 states have passed legislation to permanently use daylight saving time if Congress were to allow it, according to the National Conference of State Legislatures.