It may be March, but we’re not done with exciting environmental milestones from 2025. Coinciding with World Wildlife Day today, the global conservation org Shoal revealed that scientists named 309 freshwater fish species last year, the most recorded in a year since 2017 — and the new identifications may help protect their populations from dwindling.
Anatolian minnow
Shoal’s 2025 New Species Report is the result of researchers tirelessly scouring environments like caves, pools, and swamps across five continents. The majority of the species — 165 types of fish — were discovered in Asia, followed by 91 in South America, 30 in Africa, 20 in North America, and three in Europe.
Yang’s plateau loach
Among the fish documented are Yang’s plateau loach, a Chinese cavefish with a swim bladder that can be seen sticking out from its body, “giving the impression of a built-in life jacket”; the Anatolian minnow, which is known to live in just three streams in Turkey; and the rainbow killi, a killifish native to Congo that can only be spotted under certain weather conditions.
Black arrow tetra
“These are seasonal fishes,” killifish explorer Béla Nagy said in the report of the latter. “You have only a few weeks each year to find them alive. And finding them is complex — if there are a lot of rains, you won’t find them. And if you miss the rains, you miss the species.”
Freshwater fish are some of the world’s most threatened vertebrates, a news release states. IUCN Red List of Threatened Species assessments are crucial to securing funding and sparking action required to protect threatened habitats, but before they can happen, the species must be formally described. “A species without a name exists biologically but remains invisible institutionally,” Shoal Executive Director Mike Baltzer wrote in the report.
Marbled killi
As of March 3, one species from the list has already received IUCN assessment: Nothobranchius sylvaticus, a Tanzanian killifish, which was categorized as critically endangered in April 2025. And while Brazil’s black arrow tetra was previously reported as being sold for over $100 each in the commercial aquarium trade, its description now opens the door for conservation protection.
Ancestor cory
Many of the species on the list can be found in “just a single spring, cave system, or stretch of river,” Baltzer added in the release. As a result, population declines in these locations tend to fly under the radar, making identification even more important. “Every new species description carries both a celebration and a warning,” he noted. “It shows how much life remains hidden in freshwater ecosystems — and how much could be lost before we even understand it.”
Renny’s stiphodon
While the new identifications are a meaningful step forward, Baltzer believes the work to protect these species has only just begun. “The 309 names added in 2025 expand our knowledge of the living world,” he wrote in the report. “What happens next depends on whether that knowledge is translated into stewardship.”
See the complete list and dive deeper into some of the species’ stories.
Sicklefin redhorse
RELATED: 72 New Wildlife Species Were Identified by Cal Academy of Sciences in 2025
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