Scientists find Mexican fish never identified in U.S. in Rio Grande near Presidio

COLLEGE STATION, PRESIDIO COUNTY – Texas A&M University’s Dr. Kevin Conway, Dr. Joshuah Perkin and their team have located an extremely rare find within the waters of the Rio Grande along the U.S. and Mexico border about 6.5 miles downstream from the city of Presidio.

The Conchos shiner, Cyprinella panarcys, a fish species identified for the first time on record in the U.S. in April, was found in the mainstream of the Rio Grande at the confluence with Alamito Creek in Presidio County.

The discovery was made by Conway, an associate professor and curator of fishes for the department of wildlife and fisheries sciences Biodiversity Research and Teaching Collections at Texas A&M University, and Perkin, an assistant professor of fish ecology for the same department.

Further details are revealed in their newly published article in the Biodiversity Data Journal

“We found this fish by chance,” said Perkin. “We were conducting a survey for a declining species known as the Rio Grande shiner, Notropis jemezanus, but found none of that species. In fact, it’s quite remarkable that we could find a species never before detected in the U.S. but could not find a single Rio Grande shiner.”

Previously, the Conchos shiner was considered restricted to the upper parts of the Río Conchos drainage in Mexico, extending from the Río San Pedro at Meoqui in Chihuahua, Mexico, to the Río Florido in Durango, Mexico.

It is unique to see the species in other waters. According to Conway, there are two alternatives that could explain the unexpected discovery of the Conchos shiner in Texas.

“Either this species is native to Texas, but its presence has simply gone unnoticed until now, or we were exceptionally lucky and managed to capture a rare vagrant outside of its natural distribution.”

Conway and Perkins are excited to return to the survey area.

“The discovery of the Conchos shiner in the main stem of the Rio Grande downstream from Presidio, an area that is considered to be relatively well studied, tells us that we still have a lot to learn about the fishes within the Rio Grande drainage,” Conway said.

“This system has undergone major changes in recent years, and it is imperative that we learn as much as possible about the system now, specifically the endemic species, so that we can better manage and protect them in the years to come.”

Others involved in the discovery were Amanda Pinion, a doctoral student, and Stephanie George, a graduate student, at Texas A&M.