Etheostoma segrex Norris & Minckley
Rio Salado darter, dardo del Salado

PERCIDAE - perches, pikeperches, and darters





44 mm SL as adult female, largest male 41 mm, rarely >40 mm

Conservation Status

Considered endangered by the American Fisheries Society in 1989 (in part).


Restricted to the uppermost, mainstream Rio Salado de los Nadadores, at and near its origin from the Cuatro Cienegas basin, Coahuila, Mexico.


Common in strongly flowing, highly localized areas.

Habitat & Ecology

This species most often occupies riffles 1.5 to 3.0 m wide and 10 to 25 cm deep, of moderate turbulence over gravel/small cobble substrates. Aquatic plants (Potamogeton, Zannichellia, and Cladophora) often present. Currents estimated at 10 to 30 cm/sec. Seemingly concentrated in vegetated areas when such are present.


Essentially nothing is known of the reproductive habitats or habitats. Males in apparent breeding coloration have been taken in April, but were exceedingly rare (1 colorful male in a sample of 35 fish of mixed sexes) in an August sample.


Extraction of groundwater within the Cuatro Cienegas basin and water diversions upstream for agriculture both reduce downflow water volumes diminishing the available habitat. As with other fishes in this area, non-indigenous crayfish, molluscs, and fishes may be anticipated to result in ecosystem-level changes that undoubtedly will influence this species in the near future.

Conservation Actions

A substantial proportion of the Cuatro Cienegas basin, comprising the apparent source of water for the upper Rio Salado de los Nadadores, were set aside in 1994 as a biological preserve, which should assist in maintaining flow within this speciesU habitats. Specific conservation actions are, however, yet to be proposed or implemented.

Conservation Recommendations

Devise and implement conservation actions preventing further loss and change of habitat and prohibit introductions of non-indigenous organisms. Especially needed are provisions to maintain discharge volumes and prevent additional modification of local stream channels, which are seriously impacted by grazing and other human-induced activies.

Important References


W. L. Minckley, Department of Zoology, Arizona State University, Tempe, Arizona 85287-1501. 1 June 1998.

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