Do goldfish really have a 3-second memory? (2021)
www.livescience.com

... Goldfish are known for their orange hues and terrible memories. One common saying even claims that these creatures have a mere 3-second recall.

However, this is a complete myth that, despite its lack of scientific backing, has spread widely and remained largely undisputed by the public for decades.

"What is baffling is that it's pretty much the same wherever you go in the world," Culum Brown, an expert in fish cognition at Macquarie University in Australia, told Live Science. "In some places, it's 2 seconds, and in others, it's 10 -- but it's always short."

In reality, goldfish (Carassius auratus) have much longer memories -- spanning weeks, months and even years, Brown said. And the science to back this up has been around for more than 60 years.

"We've known about the reasonably good memories of goldfish since the '50s and '60s," Brown said. "Despite what everybody thinks, they're actually really intelligent." ...