To appraise conservation status of the Yaqui catfish Ictalurus pricei, we reviewed literature and unpublished records on a captive stock, examined voucher specimens at museums, re-sampled historical localities in the Yaqui, Mayo, and Fuerte river basins, and we surveyed rivers further south. A total of 72 specimens of native Ictalurus was collected in the Yaqui, Fuerte, Sinaloa, Culiacán, and San Lorenzo river basins. No native Ictalurus was collected in the Mayo Basin. Distribution of the Yaqui catfish appears restricted to the Yaqui, Mayo and Fuerte river basins, all of which now harbor nonnative blue (I. furcatus) and channel (I. punctatus) catfishes. The nonnative black bullhead (Ameiurus melas) is now known from the Yaqui Basin and the flathead catfish (Pylodictis olivaris) has been recorded anecdotally in the Yaqui Basin. Threats to the Yaqui catfish have increased in recent years and hybridization with the channel catfish now appears widespread. We conclude that the Yaqui catfish should be considered endangered throughout its range and that status of native populations of Ictalurus in the United States and Mexico should be reviewed and management intensified. Para evaluar el estatus de conservación del bagre de Yaqui Ictalurus pricei, revisamos la literatura y registros no publicados de una línea cautiva, examinamos ejemplares de referencia de museos, muestreamos nuevamente las localidades históricas en las cuencas de los ríos Yaqui, Mayo, y Fuerte y muestreamos los ríos más al sur. Recolectamos un total de 72 ejemplares de Ictalurus nativos en las cuencas de los ríos Yaqui, Fuerte, Sinaloa, Culiacán, y San Lorenzo. No recolectamos ejemplares de Ictalurus nativos en la cuenca del Mayo. La distribución del bagre de Yaqui parece estar restringida a las cuencas de los ríos Yaqui, Mayo, y Fuerte, las cuales albergan actualmente los bagres no-nativos I. furcatus y I. punctatus. El bagre no-nativo Ameiurus melas se conoce para la cuenca del Yaqui y el bagre Pylodictis olivaris se registra anecdóticamente para la cuenca del Yaqui. Las amenazas para el bagre Yaqui se han incrementado en años recientes y la hibridación con I. punctatus se ha extendido. Concluimos que el bagre de Yaqui deberá considerarse como en peligro de extinción a lo largo de su distribución y que el estatus de las poblaciones remanentes de Ictalurus en los Estados Unidos y México deberá revisarse e intensificar su manejo.

1. Exotic species threaten native species worldwide, but their impacts are difficult to predict. 2. Stable isotope analysis was combined with field competition experiments to predict how an invasive African cichlid fish, Hemichromis guttatus, might affect native fish in the desert springs of Cuatro Ciénegas, Mexico. 3. Stable isotope analysis suggested diet overlap between the invader and juvenile endemic cichlids, and field experiments verified that the invader reduces growth rates of the juvenile endemics through competition, but has smaller effects on adults. 4. Competition between juvenile endemic cichlids and the invader was asymmetric, with the exotic out-competing the native, suggesting the potential for competitive exclusion if the invasion is not stopped. 5. These results suggest that exotic removal programmes in Cuatro Ciénegas should focus on removing/reducing populations of the exotic cichlid in habitats where juvenile native cichlids are concentrated. 6. This approach could help focus efforts to manage exotic species before populations of native species have crashed, when it is too late to intervene. Copyright © 2011 John Wiley & Sons, Ltd.

Full text here: "This important book is basically about fishes of Arizona and very small areas of adjacent U.S. states, as well as all of the Mexican states of Baja California (North and South) and Sonora, and a very small piece of westernmost Chihuahua. After a short introduction (five pages), the first 17 pages of Chapter 2 provide background on topography, as well as geologic, climatologic, and vegetation history relevant to ecology and evolution of the natural aquatic ecosystems of a much broader region—all major North American deserts. The next 24 pages are an overview of the extensive recent human alterations of aquatic systems in the hydrologically defined focal area. Conservation issues are mentioned in Chapter 2, but Chapter 3 focuses on that and although short (4.5 pages), it is anything but sweet, strongly criticizing the political system and management agencies for failure to apply sound science and allowing the long, continual decline of native fishes to go unchecked. Chapter 4 (203 pages) contains brief guides to anatomy and identification, family and species keys, and very well-done, comprehensive species accounts for 173 species (75 native, including four undescribed). Content covering northwest Mexico is noticeably lighter than for Arizona. All species ever recorded are included, whether or not they have self-sustaining populations. A very strong point is the book's comprehensive (72 pages) Literature Cited section, including substantial “gray” literature that previously had been underutilized and hard to find. I would have liked to have seen more citation of “raw” data (e.g., museum catalog numbers for key records) and was a bit surprised to see illustrations ranging from many very simple line drawings (little more than outlines) through occasional black-and-white photographs, but there are also many higher quality line drawings with greater detail and 47 nice color plate illustrations. Dot and shaded maps are provided for native species only. I found very few errors, all minor, and overall found this to be an authoritative and valuable contribution on this important and very much imperiled fauna and the complex issues that imperil it."

The mission of the Desert Fishes Council is to preserve the biological integrity of North America's desert aquatic ecosystems and their associated life forms, to hold symposia to report related research and management endeavors, and to effect rapid dissemination of information concerning activities of the Council and its members.

The mission of the Desert Fishes Council is to preserve the biological integrity of North America's desert aquatic ecosystems and their associated life forms, to hold symposia to report related research and management endeavors, and to effect rapid dissemination of information concerning activities of the Council and its members.

The mission of the Desert Fishes Council is to preserve the biological integrity of North America's desert aquatic ecosystems and their associated life forms, to hold symposia to report related research and management endeavors, and to effect rapid dissemination of information concerning activities of the Council and its members.

The mission of the Desert Fishes Council is to preserve the biological integrity of North America's desert aquatic ecosystems and their associated life forms, to hold symposia to report related research and management endeavors, and to effect rapid dissemination of information concerning activities of the Council and its members.