‘Thick’-lipped creature found in ‘swiftly flowing’ river. It’s a new species
In a clear river of Switzerland, a “thick”-lipped creature swam through the “swiftly flowing” waters and tucked itself under a stone on the riverbed. Suddenly something zapped it and caused it to float to the surface.
Scientists scooped up their catch — and realized they’d discovered a new species.
A team of scientists spent two years visiting rivers and lakes in Switzerland as part of an aquatic biodiversity project. They suspected some of the fish living in these waterways might be misidentified, according to a study published July 2 in the peer-reviewed Journal of Fish Biology.
Researchers collected dozens of fish through electrofishing and searched archive collections for older specimens, the study said. Once they’d accumulated enough, the team analyzed the DNA of the fish and compared their appearances.
A pattern eventually emerged: Some of the river-dwelling fish were subtly but consistently different from other known species, the study said. Researchers realized they’d discovered a new species: Barbatula fluvicola, or the North-Prealpine stone loach.
North-Prealpine stone loaches are considered “robust” and “elongate,” reaching over 3.5 inches in length, the study said. They have “deep” heads with “small” nostrils and “wide” mouths with “thick” upper lips.
Photos show the “yellowish” coloring and “dark-brown pattern” of the new species. Some fish had “very densely mottled” heads, while others had “almost plain brown” heads, researchers said.
North-Prealpine stone loaches were found in “small to medium size rivers” with “clear” and “swiftly flowing water,” the study said. The fish primarily eat insects and typically live “at the bottom of rivers under stones and among pebbles” but were “sometimes close to larger rocks when in more rapid deeper waters.”
Researchers said they named the new species after the Latin word for “inhabitant of rivers” because of its natural habitat.
The North-Prealpine stone loach “seems to be abundant” and has been found in several rivers of Switzerland and neighboring regions of Austria and Germany, the study said.
The new species was identified by its body proportions, head shape, internal anatomy and other subtle physical features, the study said. DNA analysis found the new species had at least 2% genetic divergence from related species.
The research team included Bárbara Calegari, Jörg Freyhof, Conor Waldock, Bernhard Wegscheider, Dario Josi, Lukas Rüber and Ole Seehausen.
The team also discovered a second new species in Switzerland: the lake stone loach.
This story was originally published July 11, 2025 at 4:02 PM with the headline "‘Thick’-lipped creature found in ‘swiftly flowing’ river. It’s a new species."
