In Search of a Threatened Sonoran Minnow

El grupo en El Rancho Aribabi

In May 2022 three Sky Island Alliance staff members from Sonora — Angel García, Miguel Enríquez, and Mónica Montaño — joined a group of native fish researchers and conservationists in the Sky Islands region. Their mission? To find and learn more about an endangered minnow that lives here and nowhere else in the world.

Joining our staff were Dr. Mariana Mateos (a professor in Texas A&M’s Department of Ecology and Conservation Biology), Dr. Alejandro Varela Romero (a researcher in the University of Sonora’s Department of Scientific and Technological Research), Doug Duncan (a retired U.S. Fish and Wildlife Service biologist), and Alexsandre Gutiérrez (a PhD student from the University of Sonora).

The group met at Rancho El Aribabi to start monitoring native fish in the surrounding areas of the Concepción River, particularly the endangered species Poeciliopsis jackschultzi. This minnow prefers spring-fed ciénega habitats between Imuris and Nogales, Sonora, which have mostly disappeared within its small range due to groundwater extraction and road construction.

The last monitoring of P. jackschultzi was in 2001. At that time the fish’s numbers were extremely low, and it had disappeared from several sites. During our 2022 monitoring, we noted the disappearance of at least one more occurrence site (now completely dry), as well as invasive species.

As you can see below, we took water samples for environmental DNA analysis and collected fish with traps and nets. Genetic analysis of these samples will be needed to verify the identity of the species, due to the great similarity of the region’s two native minnows (P. occidentalis and P. jackschultzi).

Muestreo de agua
Captura de peces en redes
Colecta de peces en redes

Mónica Montaño: “It was great to be able to support this project in all its stages — from sampling fish to processing data, taking photos, and identifying species. It helped me to learn more about our region’s native and introduced fish.”

Fotografiando peces
Poeciliopsis jackschultzi
Identificando especies

Ángel García: “Supporting this project helped me see the real harms caused by the misuse of water sources and how it can lead to the disappearance of species. We found springs, swamps, and rivers that had been degraded or completely lost due to water diversions, road construction, pollution, and invasives.”

Rio contaminado
Especie invasiva
bombeo de agua de manantial

We hope to have good news after the genetic analyses are completed and that this isn’t the last of P. jackschultzi — so stay tuned! Meanwhile, at Sky Island Alliance we’ll continue working to protect, restore, and fight for the conservation of our precious water sources.

Learn more about P. jackschultzi.