The Northwestern Sierra Madre Occidental of Mexico is a rugged mountain range covering portions of Sonora, Chihuahua, Durango and Sinaloa, and is drained by multiple Pacific Slope Rivers to the west and the Casas Grandes, Conchos, and Nazas to the east. The overall area is topographically, climatically and biotically diverse, ranging from endorheic basins (Casas Grandes) to mountainous areas elevations up to 3348 m, average mean temperatures from 10-20°C and precipitation from 250- 1100 mm/yr. The region is also geological complex that, combined with these other variables, provides a great diversity of both aquatic and terrestrial habitats conducive to both biotic endemicity and diversity. The overall diversity of the region has contribiited to the recent listing of this region by Conservation International as one of six new high-priority biodiversity hotspots. Our understanding of the aquatic and terrestrial biodiversity of this region, however, is poor and in urgent need of rapid investigation by collaborative communities. The combination of an incredibly rugged landscape, drug and bandit activities and indigenous peoples that have not always been welcoming to visitors has resulted in a general paucity of roads in the region, and the lack of access has limited inventory studies. Recently, however, access to the region has changed dramatically and many of the areas are now accessible enough for logging, mining, and agriculture practices, all exerting extreme pressures in some areas on the biodiversity. In addition to human-induced changes to these diverse ecosystems, impacts of invasive aquatic species are becoming more and more apparent, and the potential for severely reducing population sizes of species or their extirpation or extinction is real. While several invasive or exotic species are identified as potentially destructive to these communities, the exotic Rainbow Trout (Oncorhynchus mykiss) that is derived from hatcheries or culture facilities within the region represents one of the most critical threats to the aquatic and semi-aquatic biodiversity. The native trout of mainland Mexico represent the southern- most salmonids, and are at imminent risk of introgression and/or replacement by feral Rainbow Trout, Oncorhynchus mykiss. Our recent survey efforts have expanded the known diversity and ranges of each of several distinct forms, which we feel represent valid species. We discuss our discovery of multiple new species from the Sierra Madre Occidental and focus on a new species of trout restricted to the upper Conchos drainage, the first native species of Oncorhynchus known to occupy the Atlantic Slope in Mexico. Many of these taxa are restricted to small areas of intact habitat in headwater areas of high-elevation streams, and are at risk from a suite of human-associated perturbations, emerging diseases, and introduced species. These fishes occupy unique habitats, and represent a diverse portion of the Mexican montane ichthyofauna. The habitats on which they depend support a wide range of other aquatic organisms, most of which are grossly understudied. The discovery of the Conchos Trout derived primarily by GARP niche modeling of a subset of localities of previously sampled undescribed native Mexican trout, provides only a snapshot of the biodiversity awaiting to be discovered in this region. The rugged landscape of the Sierra Madre Occidental simply precludes routine sampling at easily accesible locations of streams and most sampling locations require time-intensive access. In an effort to rapidly assess the biodiversity of rivers of this region we employed this method to aid in predicting the most suitable and highly probable Mexican trout niches in the region. This method offered highly efficient and powerful results that not only predicted the occurrence of a previously unknown trout in the upper Rio Conchos but also provided excellent predictions of available habitats in drainages where previously unknown trout have been discovered by the Truchas Mexicanas team in the last nine years. Multiple threats exist to the biodiversity of the northern Sierra Madre Occidental, including uncontrolled introductions of exotic and invasive species, emerging diseases such as whirling disease, Myxobolus cerebralis, infectious pancreatic necrosis (IPN), iridioviruses and pathogenic water mold, Saprolegnia ferax, land-use practices leading to habitat degradation via overgrazing, logging, deforestation and road construction, increasing human population growth, over-fishing or overharvesting of aquatic resources and global climate cliange reducing surface and ground water in the area and creating environments more conducive to the spread of invasive species, congregated and dense human populations, and emerging diseases. Immediate actions need to be developed to aid in public education as to the threats to these ecosystems, protection of areas, assessment of diversity, and sustainable development throughout the region that incorporates a likely highly successful ecotourism system for the region.

A complex of little-studied catfishes of the genus ⬚Ictalurus⬚ is native to Pacific drainages of the Sierra Madre Occidental and interior drainages of Northwest Mexico. Its only described member, ⬚Ictalurus pricei⬚, is protected by the Mexican and US governments and given varied conservation status by diverse other conservation organizations. We contribute new data and a review of previous work to partially rectify prior inadquacies of genetic and conservation status information on the complex. Sequence data for the cytochrome b (⬚cytb⬚) and 12S ribosomal (⬚12SrRNA⬚) mitochondrial genes provide new diagnostic molecular characters for ⬚I. pricei⬚ and both genes display intra-specific variation. The only ⬚I. pricei⬚ specimens we could obtain, however, despite extensive field collection efforts, were from a captive broodstock established starting 20 years ago for conservation purposes. We provide basic, previously unpublished information about the history and, unfortunately, recent apparent demise of that captive stock. Non-native catfishes are widely introduced throughout the range of the ⬚pricei⬚ complex and, along with habitat degradation, represent a significant, but still very little-studied threat to its genetic integrity and persistence. Conservation of the Yaqui catfish is clearly a complicated issue with much remaining to be learned, but it is clear that current levels of protection do not adequately reflect its critical conservation plight and management efforts to date have failed to provide appropriate, long-term conservation actions and much-needed research.

Este proyecto se refiere a dos grupos de peces incluidos en la Norma Oficial Mexicana-059-SEMARNAT-2001 (NOM-059). El primero es un grupo taxonómico, la familia Cichlidae (mojarras de agua dulce), del cual aparecen en la NOM-059 ocho especies, seis de ellas carentes todavía de la ficha correspondiente; todas se asignaron en la NOM erróneamente al género Cichlasoma, a pesar de que desde hace más de 20 años quedó demostrado que ese taxon no existe en México (Kullander, 1983). De las seis especies sin ficha, en el sur de México están C. grammodes (excluida de la presente propuesta por estar ya incluida en otra), C. (= Vieja) hartwegi, C. intermedium (= V. intermedia), C. (= Thorichthys) socolofi y, en el norte, C. (= Herichthys) steindachneri y C. (= Herichthys) minckleyi, esta última con un interesante polimorfismo trófico. El segundo grupo abordado en esta propuesta se refiere a los peces de la frontera sur (entendida aquí como toda la península de Yucatán y el estado de Chiapas) enlistados en la NOM-059. Además de los cíclidos mencionados, este segundo grupo consiste en once especies: Astyanax armandoi, los Cyprinodon endémicos de la laguna de Chichancanab, Quintana Roo (C. beltrani, C. labiosus, C. maya, C. simus y C. verecundus – la NOM no toma en cuenta todavía al sexto, C. esconditus Strecker 2002, ni al séptimo, C. suavium Strecker 2005), Poecilia velifera, Profundulus hildebrandi, Potamarius nelsoni, Ogilbia (=Typhliasina) pearsei y Ophisternon infernale; la NOM contempla además a Rhamdia guatemalensis, que ya cuenta con una ficha, a pesar de que su validez taxonómica ha sido cuestionada (Silfvergrip 1996), y a pesar de su amplísima distribución y abundancia. El objetivo central de la contribución fue elaborar las fichas correspondientes y obtener el valor que asigna a cada una de estas 16 especies el Método de Evaluación del Riesgo de Extinción de las especies silvestres en México (MER), para recomendar su reclasificación o su exclusión de la lista, si fuera necesario. La información necesaria se ha tomado de la literatura, tanto publicada como “gris”, ésta última integrada fundamentalmente por datos inéditos de los investigadores participantes, sus estudiantes y otros colegas. Como resultado de lo anterior, se anexan tres propuestas formales de cambio de categoría de riesgo: C. beltrani (de [P] a [A]), Th. socolofi (de [Pr] a [A]) y V. hartwegi (de [Pr] a [A]). En el caso de A. armandoi, la ficha incluye y fundamenta una observación sobre el carácter dudoso de su identidad taxonómica, aunque, por principio precautorio, no se propone (todavía) excluirla de la NOM. Las demás especies estudiadas permanecen sin cambios en su categoría de riesgo. Además, siempre con base en la aplicación del MER, se recomienda la inclusión de otras siete especies de la frontera sur hasta ahora ignoradas por la NOM-059: Astyanax altior, Cyprinodon esconditus, C. suavium, Fundulus grandissimus, F. persimilis, Lacantunia enigmatica y Menidia colei. Finalmente, se recomienda formalmente la exclusión de Rhamdia guatemalensis de la NOM-059.