Fish GPS? Scientists find goldfish go farther next to certain stripes

Changing their surroundings reveals how the creatures gauge distance using visual density of environment

Goldfish may spend most of their time swimming up and down a glass tank but researchers have found they have a sophisticated navigation system that allows them to estimate distance.

While researchers have previously shown a wide array of fish can navigate efficiently, questions remained about the mechanisms involved. Understanding those, scientists say, could help shed light on whether similar brain cells are involved in the internal GPS of the human brain.

“We want to know where are those cells appearing on the evolutionary tree,” said Dr Adelaide Sibeaux, of the University of Oxford, who is first author of the latest research.

Writing in the journal Proceedings of the Royal Society B, Sibeaux and colleagues report how they created a tank with 2cm-wide black and white vertical stripes on the walls, connected by similar stripes across the floor.

The team trained nine goldfish to swim along the tank and, when waved at after they had travelled 70cm, to return to their starting position.

The team then tested the fish on whether they could estimate the same distance without the aid of gestures.

For six goldfish, these results were compared with the distance they travelled when the pattern was switched to 1cm wide vertical stripes, a checked pattern with 2cm squares, and to 2cm-wide horizontal stripes aligned with the fish’s direction of travel.

Each fish made the journey 45 times for each background pattern, and was recorded on video.

The team found the goldfish travelled 74cm on average, give or take 17cm, when presented with the vertical, 2cm-wide stripes. Similar results were found when the background was switched to the checked pattern. However the fish turned back markedly sooner when the stripes were vertical but narrow – overestimating the distance they travelled by about 36%.

When horizontal stripes were used, the distance the fish swam varied enormously. “The fish were totally inconsistent,” said Sibeaux.

The team say the results suggest goldfish use a type of “optic flow mechanism” based on visual density of the environment – in other words they kept track of how frequently the vertical pattern switched between black and white to estimate how far they had travelled. As the world appeared to pass by faster when the width of the stripes was reduced, the fish overestimated how far they had swum.

Sibeaux said a different optic flow mechanism is used by mammals including humans, based on the angular motion of the visual features. However, the results suggest the use of visually based distance information arose early in our evolutionary past, given it is widespread across different groups of animals.

The team say other mechanisms might also be at play, noting the goldfish were more accurate in gauging distance when their start position was closer to the end of the tank, while for some the number of fin beats they made was associated with how far they swam.

Prof Colin Lever of the University of Durham, who was not involved in the study, said the research suggested goldfish at least partly use the rate of optic flow to estimate distance, although other clues might also be used.

“This study is important and novel because, although we already know that fish respond to geometric information regarding direction and distance, we don’t know how they estimate distances,” he said.

“It’s exciting to explore fish spatial mapping because fish navigation evolved before mammals, and fish navigation has to negotiate the vertical dimension more fully [than most mammals].”


Nicola Davis Science correspondent

The GuardianTramp

Related Content

Article image
‘Alien goldfish’ may have been unique mollusc, say scientists
Researchers think they may have solved enduring mystery of where Typhloesus wellsi sits on tree of life

Nicola Davis Science correspondent

21, Sep, 2022 @5:00 AM

Article image
Social rules help varied personalities work as a team, fish study shows
Stickleback foraged more efficiently with conventions present than when individuals behaved independently

Nicola Davis, Science correspondent

02, Mar, 2023 @7:00 PM

Article image
Scientists find some fish can ‘recognise themselves’ in mirror
Wrasse passes intelligence test in disputed study, challenging ‘vacant’ reputation of fish

Hannah Devlin Science correspondent

07, Feb, 2019 @7:00 PM

Article image
Sharks love jazz but are stumped by classical, say scientists
A study at Macquarie University in Sydney found that sharks could recognise jazz – if there was food on offer

Ben Beaumont-Thomas

10, May, 2018 @9:21 AM

Article image
Tusk master: Wally the walrus departs Isles of Scilly and heads north
Marine experts hope the creature is on his way back to the Norwegian archipelago of Svalbard

Steven Morris

03, Aug, 2021 @11:08 AM

Article image
Killer whales seen in river Clyde
Pod of orcas spotted between Dunoon and Gourock, thought to be hunting seals or porpoises

Matthew Taylor

22, Apr, 2018 @1:32 PM

Article image
Weatherwatch: sunbathing carp grow faster and fitter than their timid cousins
Carp that soak up the sun are fitter, and bold fish benefit more by sunbathing for longer

Paul Brown

11, Jun, 2018 @8:30 PM

Article image
A moment that changed me: seeing my first moth fish | Fiona Gell
That incredible little fish, and some guidance from a truly inspirational conservationist, sent my life in the right direction, says the marine conservation officer Fiona Gell

Fiona Gell

17, Nov, 2017 @10:33 AM

Article image
Scientists discover how mosquitoes can ‘sniff out’ humans
Unlike most animals, mosquitoes can pick up on odours via several different pathways, study suggests

Sascha Pare

18, Aug, 2022 @3:00 PM

Article image
Discovered. A fish with a warm heart
New research demonstrates a remarkable adaptation in a fish. It has a warm heart

Henry Nicholls

15, May, 2015 @10:42 AM