Five Cool Fishes that Went Extinct
About: Edge Effects are shorter experimental reflections on ideas that take shape in the margins between Tangled Nature’s deeper dives.
One of my great joys is teaching people about the surprising beauty and diversity of fishes. For example, many think that colorful fish are only found in the ocean, on coral reefs. Then when I show them a picture of a bright pumpkinseed sunfish or a colored-up male darter, their assumptions disintegrate.
There are other show-stoppers too. But these aren’t the ones we celebrate, rather they’re the ones we mourn. They are the fishes that went extinct because of us. Species we let slip through our fingers, and that remind us how we keep doing irreparable damage, even when we know better.
In this post, I want to call attention to a handful of these species. Part of this is to simply showcase the beauty of what we’ve lost. Another part is to communicate the stakes. Extinction often sounds abstract, but it isn’t, it’s happening around us.
So, without further ado,
Here are a handful of cool fishes that went extinct that I’d like to introduce you to.
The Chinese Paddlefish. There are only two paddlefish species on Earth. One, the American paddlefish Polyodon spathula, still swims in the Mississippi River and appears relatively secure. The other is the Chinese paddlefish Psephurus gladius, which was declared extinct in 2019.
The Chinese Paddlefish was native to the Yangtze River, and was an enormous fish, reaching lengths up to 7m. Beauty with fishes is subjective (Rypel et al. 2021), but it’s hard to look at this one and not feel something. Its almost glowing rostrum (the long conical nose) was a sophisticated sensory organ, packed with ampullae of Lorenzini. These structures allowed the fish to detect the faint electrical signals produced by the kinetic motion of zooplankton - its preferred food. Like other sturgeons and paddlefishes, it was likely long-lived and highly sentient. The species appears in cultural writings and paintings stretching back millennia. In The Huainanzi (~4,000 years BP), the paddlefish is described as “listening” to the river, responsive to rhythms, and perhaps even drawn to the beats and sounds of human music on the shores.
Its decline started, like so many large river fishes, with dams and concrete. Completion of the Gezhouba Dam in 1981 fragmented the river and the paddlefish from its ancestral spawning grounds. Overfishing was long problematic in the basin and hastened the decline. During the 1970s, fishers were reportedly hauling out as much as 25 tons of paddlefish per year. Since 2000, there have been only two confirmed sightings, with the last one being a 3.5m female captured in 2002. The species was declared extinct in 2019, after numerous exhaustive surveys (Zhang et al. 2020).
Resources
https://en.wikipedia.org/wiki/Chinese_paddlefish
ATF 2026. Ancient giants of the Missouri River. All Things Fish
Dudgeon, D. 2024. Prospects for conserving freshwater fish biodiversity in the Anthropocene: a view from southern China. Integrative Conservation 3: 294-311.
Scarnecchia, D.L. 2023. The Extinction of the Chinese Paddlefish Psephurus gladius: transnationalism, technology transfer, and timescape. Reviews in Fisheries Science & Aquaculture 31: 396-419.
Zhang, H., I. Jaric, D.L. Roberts, Y. He, H. Du, J. Wu, C. Wang, and Q. Wei. 2020. Extinction of one of the world’s largest freshwater fishes: lessons for conserving the endangered Yangtze fauna. Science of the Total Environment 710: 136242.
Scioto Madtom. Little is known about the Scioto Madtom. Like other madtoms, it was a diminutive freshwater catfish species. But this species was especially restricted: apparently found only in Big Darby Creek, a tributary of the Scioto River in Ohio. Just 18 specimens were ever collected, all but one from a single location known as “Trautman’s Riffle” in 1957. After that, it was never encountered again (USFWS 1996).
Its disappearance remains a mystery, but only in the academic sense. The Big Darby watershed changed dramatically after the 1950s, and madtoms are notoriously sensitive to water quality. This species’ decline also coincided with the rise of the northern madtom, a close relative that likely competed with it.
The biologist who first described the species suggested the Scioto Madtom may have lived in crayfish burrows. If true, that behavior could have made it harder to detect the fish during surveys. But there’s also a darker twist: native crayfish populations have collapsed across much of their range (Taylor et al. 1996). If the madtom depended on burrows, the disappearance of crayfish may have indirectly contributed to decline and eventual extinction of the fish. Nature is often linked in complex ways.
Resources
https://en.wikipedia.org/wiki/Scioto_madtom
https://www.metroparks.net/blog/requiem-for-a-fish-the-secrets-of-the-scioto-madtom/
Taylor, C.A., M.L. Warren Jr., J.F. Fitzpatrick Jr., H.H. Hobbs III, R.F. Jezernic, and W.L. Pflieger, and H.W. Robison. 1996. Conservation Status of Crayfishes of the United States and Canada. Fisheries 21 25-38.
USFWS 1996. Scioto Madtom (Noturus trautmani) 5-year review and evaluation. Ohio Ecological Services Field Office. Columbus, OH.
Caterina Pupfish. The Caterina pupfish Megupsilon aporus was a tiny killifish endemic to a single natural spring “El Potosí” in Nuevo León, Mexico. It was the only known member of its genus, having diverged from its closest relatives roughly 7M years ago. Males displayed surprisingly elaborate courtship behaviors (Liu and Echelle 2013), including opercular rotations during aggressive encounters and distinctive “jaw-nudging” during mating.
El Potosí was itself a remnant of a much larger ancient lake within the endorheic La Hediondilla basin. During the Pleistocene, this system may have connected to the Río Conchos and tributaries of the Río Bravo to the north. But modern changes were extremely fast and intense. In 1985, intensified groundwater pumping to support corn and potato agriculture shrank the spring to 1/10th its former size. By 1986, the once large spring was a shallow irrigation ditch.
Over-pumping was the primary driver of the pupfish’s demise (Valdés González et al. 2018). By 1994, the species was extinct in the wild. Captive breeding programs kept it alive for a time, but never succeeded in re-establishing populations. The last female died in 2013; the last male followed in 2014.
The story of the Caterina pupfish echoes that of Tulare Lake, California: another sacrificial landscape. The difference, of course here, is that this fish cannot return.
Resources
https://en.wikipedia.org/wiki/Catarina_pupfish
Liu, R.K., and A.A. Echelle. 2013. Behavior of the Caterina Pupfish (Cyprinodontidae: Megupsilon aporus), a severely imperiled species. The Southwestern Naturalist 58: 1-7.
Valdés González, A. L.M. Estévez, M.E.A. Villeda, and G. Ceballos. 2018. The extinction of the Caterina pupfish Megupsilon aporus and the implications for the conservation of freshwater fish in Mexico. Oryx 54: 154-160.
Thicktail Chub. The Thicktail Chub was a large, likely carnivorous minnow native to California’s Central Valley. It was an important part of the original valley-floor assemblage, alongside Sacramento Pikeminnow, Sacramento Sucker, Sacramento Blackfish, and Tule Perch (Moyle 2002). The species occupied large lowland lakes, slow-moving river reaches, and sloughs, and it occasionally hybridized with California Hitch (Lavinia exilicauda) (Miller 1963).
In the early 1800s, Thicktail Chub were abundant enough to appear regularly in the San Francisco fish markets, and intriguingly also, on the menus in Sacramento saloons (Schulz 1980). But the decline was fast. By the late nineteenth century, reports noted the fish had become scarce and no longer appeared in markets (Moyle 2002). Few specimens were collected at all during the twentieth century, and the last known individual was sampled near Rio Vista in 1957.
None of California’s Central Valley endemics fared well when the region was transformed (Moyle et al. 2011). But the Thicktail Chub seemed especially vulnerable. My suspicion is that it relied on tule plants and tule-dominant marshes for spawning or recruitment. These emergent wetlands once blanketed the valley floor, but as they were drained and converted, the chub disappeared alongside them. Other impacts likely compounded with the loss of the tules. Habitat destruction coincided with the introduction of non-native predators, particularly Striped Bass Morone saxatilis and sunfishes Lepomis and Micropterus spp. As with so many extinctions, it wasn’t one blow, but many that landed simultaneously.
Resources
https://en.wikipedia.org/wiki/Thicktail_chub
Miller, E.E. 1963. Synonymy, characters, and variation of Gila crassicauda, a rare California minnow, with account of its hybridization with Lavinia exilicauda. California Fish and Game 49: 20-29.
Moyle, P.B. 2002. Inland Fishes of California. University of California Press.
Moyle, P.B., J.V.E. Katz, and R.M. Quiñones. 2011. Rapid decline of California’s native inland fishes: a status assessment. Biological Conservation 144: 2414-2423.
Schulz, P.D. 1980. Fish remains. Pages 1-18 in Praetzellis M., A. Praetzellis, and M.R. Brown editors. Historical archeology at the Golden Eagle site. Sonoma State University.
New Zealand Grayling. Once widespread in New Zealand’s rivers, the New Zealand Grayling Prototroctes oxyrhynchus was a medium-sized migratory fish found nowhere else on Earth. It was known to the Māori by multiple names which reflected life-stages and cultural importance. Despite its grayling name, it was not closely related to the Northern Hemisphere graylings, but instead was most closely allied with the Australian Grayling, and more distantly, the northern smelts.
Human arrivals reshaped New Zealand’s biodiversity and ecosystems. Polynesians settled in the region around 1280, followed by Europeans in the late 1700s. These events triggered huge amounts of habitat change and widespread species loss (Scarsbrook et al. 2023). Most of the extinctions were birds, and the grayling stands out as the only known fish in New Zealand to completely vanish.
Historical accounts suggest the species was once found across much of the country (Lee and Perry 2019). But during the nineteenth century, it disappeared mysteriously and completely from the rivers. The last confirmed sighting occurred in 1929, and the species was officially declared extinct in 2018. Recent evidence hints it may have persisted longer than previously thought, possibly into the 1970s, in hard-to-sample patches (Lee and Perry 2019).
Almost nothing is known about its biology.
Resources
https://en.wikipedia.org/wiki/New_Zealand_grayling
Lee, F., and G.L.W. Perry. 2019. Assessing the role of off-take and source–sink dynamics in the extinction of the amphidromous New Zealand grayling (Prototroctes oxyrhynchus). Freshwater Biology 64: 1747-1754.
Scarsbrook, L., J.J. Mitchell, M.D. Mcgee, G.P. Closs, and N.J. Rawlence. 2023. Ancient DNA from the extinct New Zealand grayling (Prototroctes oxyrhynchus) reveals evidence for Miocene marine dispersal. Zoological Journal 197: 532-544.
Takeaways
“The eyes of the future are looking back at us and they are praying for us to see beyond our own time.” ~Terry Tempest Williams, Refuge: An Unnatural History of Family and Place
I have a really cool and interesting job, but talking about extinctions is probably the saddest part of it. Maybe some of you, while reading about these species, experience some of the same feelings: shame and disgust, mixed with an odd kind of intrigue. When I worked in California, I often felt like I was slowly writing obituaries of all those native fishes (Rypel and Moyle 2024). The worst part is, we often know how to prevent extinction from happening, but we just can't stop ourselves. We're incorrigible in this way.
Going through the whole list of recently extinct fishes, there are two important patterns I see. (1) Many of these fishes were endemics with very small geographic distributions: often just a single ecosystem. Of course, we should also be worried about declining species that are cosmopolitan. However, fishes with tiny ranges appear to be extremely vulnerable to leaving us. This makes sense - there is no back up plan. Draining all their habitat is, of course, an expedited path to annihilation. (2) Another pattern that emerges repeatedly is that extinction is rarely caused by a single impacts. It is compound blows, sometimes simultaneously, or one after another. And if we aren't watching, they can slip away fast and undetected. Dams layered on diversions, invasives stacked on habitat loss, overharvest and pollution added to climate change.
In the Tulare Lake post, I wrote about the concept of ghost ecosystems, and sacrificial landscapes. And here we are again, only this time talking about sacrificial species. The key difference with extinction however is that there is no coming back. It is an unrewindable tape. A pox on our species. Something we should be embarrassed about. And don't bet on resurrection ecology or some version of Jurassic Park to save our keisters. We can't even manage the habitats we have while species are still around to recover them from captive populations - some we spend alot of money on too. Doing better with an even smaller number of resurrected genes that already weren't fit enough to linger sounds, well, unlikely. My hope, as always, is that by talking about these embarrassing stories, we learn to do better with the species still with us. But, I think we all know it's unlikely we will change our ways. So, we go on writing obituaries such as these (Moyle and Rypel 2024; Anthony 2025; Pfeiffer 2025; Rypel 2025). And we go on being sad about it. The hardest part is that we usually know how to prevent these losses. The science isn’t hugely mysterious. What fails is our collective will.
But, telling these stories is not pointless. Remembering each species matters, as does bearing witness to what they can still teach us. Each name we keep alive (the paddlefish, madtom, pupfish) is our refusal to pretend these losses were inevitable or insignificant. We probably won’t stop the next extinction, but maybe we can slow it. Perhaps we can organize our science and morality enough to save one species that would have otherwise faded. At the very least, we lose the right to say I had no idea. That’s admittedly small, but is also what responsibility is about.
Go Deeper
List of Earth’s known recently extinct fishes https://en.wikipedia.org/wiki/List_of_recently_extinct_fishes
Anthony, J. 2025. Extinctions and optimism. Field Guide to the Anthropocene.
Burkhead, N.M. 2012. Extinction rates in North American freshwater fishes, 1900-2010. BioScience 62: 798-808.
Pfeiffer, B. 2025. The extinction of virtue: an imperiled butterfly and our endangered morality. Chasing Nature.
Ricciardi, A., and J.B. Rasmussen. 1999. Extinction Rates of North American Freshwater Fauna. Conservation Biology 13: 1220-1222.
Rypel, A.L., P. Saffarinia, C.C. Vaughn, L. Nesper, K. O'Reilly, C.A. Parisek, M.L. Miller, P.B. Moyle, N.A. Fangue, M. Bell-Tilcock, D. Ayers, and S.R. David. 2021. Goodbye to "rough fish": paradigm shift in the conservation of native fishes. Fisheries 46: 605-616 .
Rypel, A.L., and P.B. Moyle. 2024. Watching native fishes vanish California WaterBlog
Rypel, A.L. 2025. Being the Lorax. California WaterBlog.
Rypel, A.L. 2025. Ooze, order and disorder. Tangled Nature.
Rypel, A.L. 2026. America’s ghost lake. Tangled Nature.
Williams-Subiza, E.A., and L.B. Epele. 2021. Drivers of biodiversity loss in freshwater environments: A bibliometric analysis of the recent literature. Aquatic Conservation: Marine and Freshwater Ecosystems 31: 2469-2480.
Thank you so much for this! I am doing a school project on extinct animals and the amazing information you provided with sorces is so helpful. This topic is so interesting and needed, great job on this!!!
Great piece, Andrew. Enjoyed it even if the topic is slightly depressing!