Animals

New, Ultra-Colourful Neon Fish Species Discovered

The small, vibrant fish, found in a Brazilian island reef, is named after the Greek goddess of love.Wednesday, 26 September 2018

By Michael Greshko
Some 140 metres (420 feet) beneath the Atlantic Ocean's surface, a 'Tosanoides aphrodite' peeks out from a deep coral reef. The fish is known only from the waters around Saint Paul's Rocks, Brazil.

In the middle of the Atlantic Ocean, hundreds of feet underwater, the Greek goddess of love lives on—in the form of a dazzling reef fish.

In a new study published in ZooKeys, researchers from the California Academy of Sciences describe a new species of anthias, a common type of reef fish, named Tosanoides aphrodite or the Aphrodite anthias. The pink and yellow creature so transfixed researchers when they discovered it during a deep-water dive that they didn't notice a large sixgill shark swimming directly above them.

“This one is without a doubt the most spectacularly coloured fish I've ever described,” says Luiz Rocha, an ichthyologist with the California Academy of Sciences, in an email.

The Aphrodite anthias is also the only fish of its kind ever found in the Atlantic. All other fish in the genus Tosanoides, including Hawaii's presidentially named Tosanoides obama, live in the Pacific Ocean.

Tough Love

The Aphrodite anthias is known only from the waters around Saint Paul's Rocks, a harsh, isolated archipelago near the middle of the Atlantic Ocean, about 580 miles northeast of Brazil's coastline.

In the summer of 2017, Rocha and his colleague Hudson Pinheiro trekked to the islands, diving down to nearly 130 metres (400 feet) to survey a deep-water reef. On one dive in late June, they saw a flash of pink and yellow in the reef's nooks and crannies. Closer inspection revealed a striking fish about three inches long staring back at them. For the rest of the day, the duo worked to capture specimens of the colourful fish, on the hunch that they had seen an undiscovered species.

A male 'Tosanoides aphrodite' shortly after its collection from Saint Paul's Rocks, Brazil.

In all, Pinheiro and Rocha collected three adult males, two adult females, and two juvenile females. Males and females of the species look very different; the males make far greater use of hot pink.

Because of the islands' tininess, isolation, and placement within the Atlantic's major ocean currents, they're a perfect natural laboratory for studying how life spreads across land and sea. Since 1799, scientists have regularly visited Saint Paul's Rocks—including Charles Darwin, who noted their marine bounty when he visited in 1832. “The sharks and the seamen in the boats maintained a constant struggle [over] which should secure the greater share of the prey caught by the fishing-lines,” he later wrote in The Voyage of the Beagle.

Since 1998, Brazil has kept a small research station on the islands, giving scientists greater opportunity to study the islands' 'mesophotic' coral reefs, which live between 30 and 170 metres (100 and 500 feet) underwater. Despite being in the ocean's twilight zone, these reefs are remarkably diverse, like their better-known cousins in the shallows. Previous studies have shown that seven reef fish species at Saint Paul's Rocks can't be found anywhere else on Earth. The Aphrodite anthias is the eighth.

“The beauty of the Aphrodite anthias enchanted us during its discovery much like Aphrodite’s beauty enchanted ancient Greek gods,” the researchers write.

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Pinheiro, the study's lead author, says that he hopes the Aphrodite anthias brings more attention to mesophotic reefs. Earlier this year, a coalition of marine scientists including Pinheiro and Rocha emphasised in Science that despite being deeper underwater, these reefs face plenty of human threats, including rubbish pollution, overfishing, and disruption from climate change. As Rocha and Pinheiro dove Saint Paul's Rocks in 2017, they noticed rubbish and fishing lines littering the deep reefs that the Aphrodite anthias calls home.

“There is a whole different biodiversity hidden right there, and in many regions of the world we have documentation that we are already destroying these habitats,” Pinheiro says.

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