Revisión histórica, distribución potencial y estado de conservación de la rata endémica de México Xenomys nelsoni (Rodentia: Cricetidae) / Historical review, potential distribution, and conservation of the Mexican endemic rat Xenomys nelsoni (Rodentia: Cricetidae)

Resumen Introducción: La Rata de Magdalena, Xenomys nelsoni, es un roedor endémico de México, de distribución restringida a las selvas bajas caducifolias densas, en una pequeña región de la costa del Pacífico mexicano. Es una especie poco conocida, catalogada como "En Peligro" de acuerdo con la Unión Internacional para la Conservación de la Naturaleza (IUCN). Este desconocimiento unido a la alta tasa de deforestación de su hábitat hace que su conservación sea prioritaria. Objetivo: Realizar un recuento histórico de los registros depositados en las colecciones científicas, generar mapas de distribución potencial y analizar el estado de conservación de la especie. Método: Los datos de ocurrencia de las especies se obtuvieron de la literatura y bases de datos digitales y se analizaron por décadas. Se utilizaron los programas GARP y MaxEnt para generar los modelos de nicho ecológico. La importancia de las variables en el modelo se estimó mediante un análisis Jackknife. Resultados: A lo largo de 129 años 19 recolectores registraron 69 ejemplares, de los cuales 65 están depositados en siete colecciones internacionales y una nacional. Aunque la especie sólo se ha recolectado en Jalisco y Colima, la distribución potencial de X. nelsoni incluye también el estado de Michoacán. De esta área estimada, sólo el 1.5 % se encuentra dentro de un Área Natural Protegida. Conclusiones: Los resultados de la distribución potencial podrían ser utilizados para verificar la presencia de la especie en lugares donde no ha sido recolectada como el norte de la Reserva de la Biosfera Chamela-Cuixmala y en algunas zonas de la provincia fisiográfica Costas del Sur en el estado de Michoacán. Es necesario incrementar los muestreos en regiones poco estudiadas predichas por el modelo y aumentar el área de protección.

Abstract Introduction: The Magdalena Rat, Xenomys nelsoni, is a rodent endemic to Mexico, whose distribution is restricted to dense tropical dry forests in a small region on the Pacific coast of Mexico. It is a poorly known species categorized as "Endangered" by the International Union for Conservation of Nature (IUCN). This lack of knowledge and the high rates of deforestation of its habitat makes its conservation a priority. Objective: To summarize the historical records deposited in scientific collections, to create potential distribution maps, and to analyze the conservation status of the species. Methods: We obtained species occurrence data from literature and digital databases, analyzing them by the decade. We used GARP and MaxEnt software to generate the ecological niche models. The importance of the variables in the model was estimated using the Jackknife technique. Results: Over 129 years, 19 collectors registered 69 specimens, of which 65 are deposited in one national and seven international collections. Although the species has only been collected in Jalisco and Colima, the potential distribution for X. nelsoni also includes the state of Michoacán. Of this estimated area, only 1.5 % is in a Protected Natural Area. Conclusions: The results of the potential distribution could be used to verify the presence of the species in places where it has not been collected, such as the northern part of the Chamela-Cuixmala Biosphere Reserve and in some areas of the physiographic province Costas del Sur in the state of Michoacán. It is needed to increase samplings in the least studied regions predicted by the model and expand the area of protection.

Innovations in surgical training: exploring the role of artificial intelligence and large language models (LLM) / Inovações no treinamento cirúrgico: explorando o papel da inteligência artificial e dos grandes modelos de linguagem (LLM)

ABSTRACT The landscape of surgical training is rapidly evolving with the advent of artificial intelligence (AI) and its integration into education and simulation. This manuscript aims to explore the potential applications and benefits of AI-assisted surgical training, particularly the use of large language models (LLMs), in enhancing communication, personalizing feedback, and promoting skill development. We discuss the advancements in simulation-based training, AI-driven assessment tools, video-based assessment systems, virtual reality (VR) and augmented reality (AR) platforms, and the potential role of LLMs in the transcription, translation, and summarization of feedback. Despite the promising opportunities presented by AI integration, several challenges must be addressed, including accuracy and reliability, ethical and privacy concerns, bias in AI models, integration with existing training systems, and training and adoption of AI-assisted tools. By proactively addressing these challenges and harnessing the potential of AI, the future of surgical training may be reshaped to provide a more comprehensive, safe, and effective learning experience for trainees, ultimately leading to better patient outcomes. .

RESUMO O cenário do treinamento cirúrgico está evoluindo rapidamente com o surgimento da inteligência artificial (IA) e sua integração na educação e simulação. Este artigo explora as aplicações e benefícios potenciais do treinamento cirúrgico assistido por IA, em particular o uso de modelos de linguagem avançados (MLAs), para aprimorar a comunicação, personalizar o feedback e promover o desenvolvimento de habilidades. Discutimos os avanços no treinamento baseado em simulação, ferramentas de avaliação impulsionadas por IA, sistemas de avaliação baseados em vídeo, plataformas de realidade virtual (RV) e realidade aumentada (RA), e o papel potencial dos MLAs na transcrição, tradução e resumo do feedback. Apesar das oportunidades promissoras apresentadas pela integração da IA, vários desafios devem ser abordados, incluindo precisão e confiabilidade, preocupações éticas e de privacidade, viés nos modelos de IA, integração com os sistemas de treinamento existentes, e treinamento e adoção de ferramentas assistidas por IA. Ao abordar proativamente esses desafios e aproveitar o potencial da IA, o futuro do treinamento cirúrgico pode ser remodelado para proporcionar uma experiência de aprendizado mais abrangente, segura e eficaz para os aprendizes, resultando em melhores resultados para os pacientes.

Los receptores acoplados a proteínas G como blanco terapéutico / G protein-coupled receptors as therapeutic target

Resumen Los receptores son proteínas codificadas por el ADN, algunos de los cuales ya han sido cristalizados, lo que permite conocer los detalles de su estructura a nivel atómico y algunos aspectos de su función. Esta revisión se enfoca en los más diversos y abundantes, los receptores acoplados a la proteína G. Esta familia de receptores reconoce y media la acción de varios ligandos endógenos (hormonas, neurotransmisores, factores de crecimiento y hormonas locales) y también interviene en la patogenia de diversas enfermedades, por lo que son el blanco terapéutico de aproximadamente 30 a 40 % de los medicamentos que se emplean en la práctica clínica cotidiana y de diversas drogas ilegales. La cristalografía de rayos X es una de las herramientas clave que ha permitido observar la estructura de estos receptores en los aminoácidos que participan en esta interacción, lo que posibilita conocer el sitio de unión del ligando endógeno y de moléculas sintéticas que actúan sobre ellos para modular su acción. El modelado molecular es también una herramienta bioinformática computacional que apoya la investigación sobre la unión receptor-ligando, que hace posible el diseño y desarrollo de fármacos cada vez más específicos. A estos desarrollos se suman importantes cambios en los conceptos farmacodinámicos fundamentales.

Abstract Receptors are proteins coded by DNA, some of which have already been crystalized, thus allowing the details of their structure at the atomic level and some aspects of their function to be known. This review focuses on the most diverse and abundant family of receptors, G protein-coupled receptors. This family of receptors recognizes and mediates the action of several endogenous ligands (hormones, neurotransmitters, growth factors and local hormones) and also intervenes in the pathogenesis of various diseases, which is why they are targeted by approximately 30 to 40% of medications that are used in daily clinical practice and of various illegal drugs as well. X-ray crystallography is one of the essential tools that has allowed to observe the structure of these receptors in the amino acids that participate in this interaction, which allows to know the binding site of the endogenous ligand and of synthetic molecules that act on them to modulate their action. Molecular modeling or "docking" is also a computational bioinformatics tool that supports research on receptor-ligand binding, which allows the design and development of increasingly specific drugs. These developments have brought along significant changes in fundamental pharmacodynamic concepts.

Endocarditis infecciosa en hospital clínico Herminda Martín de Chillán: experiencia de los últimos cinco años / Infective endocarditis at Herminda Martin clinical hospital of Chillan: last five years experience

Introducción: la endocarditis infecciosa es una afección con elevada morbilidad y mortalidad, con una incidencia en Chile de 2-3 casos por 100.000 habitantes al año, con una edad de presentación en ascenso y una clínica diversa e inespecífica que requiere un manejo multidisciplinario para el manejo de estos pacientes. Materiales y métodos: estudio observacional descriptivo, se consideró el número total de fichas clínicas del hospital clínico Herminda Martín de Chillán durante los años 2015 al 2019, con diagnóstico confirmado de endocarditis infecciosa. Los datos se registraron en la hoja de recolección de datos elaborada, realizándose los análisis estadísticos pertinentes. Resultados:la muestra (n=17) que pudo ser analizada tenía una edad promedio de 53,5 años; 70,5% (DE 14,50) fueron hombres y el agente más común identificado fue Staphylococcus aureus sensible a meticilina. En promedio los pacientes recibieron 28,8 días de antibióticos y la válvula más afectada fue la aórtica. Conclusiones: la endocarditis infecciosa es una patología con una gran morbimortalidad, que presenta un cuadro clínico inespecífico capaz de simular cualquier enfermedad. Se requieren aún de más estudios que reflejen la realidad nacional.

Introduction: Infective endocarditis is a condition with high morbidity and mortality, with an incidence in Chile of 2-3 cases per 100,000 inhabitants per year, with increasing age of presentation and a diverse and nonspecific clinic that requires multidisciplinary management for treatment of these patients. Materials and methods: Descriptive observational study, the total number of clinical records of the Herminda Martín de Chillán clinical hospital during the years 2015 to 2019, with a confirmed diagnosis of infective endocarditis, was considered. The data were recorded in the data collection sheet prepared, performing the relevant statistical analyses. Results: The sample (n = 17) that could be analysed had an average age of 53.5 years (DS 14.50), 70.5% were men, and the most common agent identified was methicillin-sensitive Staphylococcus aureus. On average, patients received 28.8 days of antibiotics, and the most affected valve was the aortic valve. Conclusions: Infective endocarditis is a pathology with high morbidity and mortality, which presents a nonspecific clinical spectrum, capable of simulating any disease. Still, more studies are required that reflect the national reality

La sala lúdica: un complemento de la Clínica Dental Pediátrica Universitaria / The playroom: a complement of the University Pediatric Dental Clinic

El presente artículo muestra las diferentes actividades que realiza la salalúdica SALPEP (Especialidad en Estomatología Pediátrica, Facultad deEstomatología, Universidad Autónoma de San Luis Potosí), tanto educativascomo de preparación conductual antes de ingresar a la consulta dental, en los pacientes pediátricos así como en sus padres que acuden a la Clínica Dental Pediátrica del Posgrado. Además, se resaltan los resultados obtenidos en sus primeros doce meses de labor, los beneficios y experiencias logradas que se han refl ejado en el aumento de la calidad de la atención odontológica, en todos los aspectos...

The bacterial community structure in an alkaline saline soil spiked with anthracene

Background: The application of polycyclic aromatic hydrocarbons (PAHs) will affect the bacterial community structure as some groups will be favoured and others not. An alkaline saline soil with electrolytic conductivity (EC) 56 dS m-1 was spiked with anthracene and acetone while their effect on bacterial community structure was investigated. Results: The percentages of Acidobacteria and Actinobacteria decreased over time, while the percentage of Proteobacteria, mostly Xanthomonadales, increased. The percentage of the phylotypes belonging to the Nocardioides, Rhodococcus and Streptomyces, known degraders of PAHs, was larger in the anthracene-amended soil than in the acetone-amended and unamended soil at day 14. The phylotypes belonging to the genera Sphingomonas, also a known degrader of PAHs, however, was lower. Weighted and unweighted PCoA with UniFrac indicated that phylotypes were similar in the different treatments at day 0, but changed at day 1. After 14 days, phylotypes in the unamended and acetone-amended soil were similar, but different from those in the anthracene-spiked soil. Conclusions: It was found that incubating the soil and contaminating it with anthracene changed the bacterial community structure, but spiking the soil with acetone had little or no effect on the bacterial community structure compared to the unamended soil.

New species of Eugerres from the Usumacinta Province, México and Guatemala with a redescription of E. mexicanus (Steindachner, 1863) (Teleostei: Gerreidae)

Eugerres castroaguirrei, new species is described from the río Grijalva-Usumacinta basin of southeastern Mexico and northern Guatemala. Eugerres castroaguirrei and E. mexicanus are distinguishable from their marine estuarine congeners by the dorsal-fin origin posterior to the insertion of the pectoral and pelvic fins, a shorter and broad based supraoccipital crest, and a distinct geographic distribution restricted to freshwater habitats. Eugerres castroaguirrei differs from E. mexicanus by diagnostic characters of the body skeleton: anterior process of supraoccipital convex, infraorbital 1 with foramen, premaxillary ascending process developed with margins curved, pharyngeal plate granular and not serially arranged, and dorsal and anal fin-rays reduced. Likewise, E. castroaguirrei is characterized by an oblong and laterally thicker body (37.6-58.5% HL); greater body depth (33.8-42.1% SL), and eye diameter (23.3-31.6% HL); in addition to 16 significant morphometric characters: length of the second dorsal-fin spine 23.2-34.2% SL; depressed second dorsal-fin spine (extending to base of third to fourth dorsal-fin rays); length of second anal-fin spine 11.1-20.6% SL, depressed second anal-fin spine extending to the base of third to fourth anal-fin rays not reaching the distal point of last anal-fin ray; pelvic-fin spine length 49.7-65.0% in the first pelvic-fin ray length.

Eugerres castroaguirrei, es descrita como especie nueva de la cuenca del sistema de ríos Grijalva-Usumacinta, en el sureste de México y norte de Guatemala. Eugerres castroaguirrei y E. mexicanus se distinguen de sus congéneres marino estuarinos por el origen de su aleta dorsal que es posterior a la inserción de las aletas pectorales y pélvicas, así como por su cresta supraoccipital de longitud corta y base amplia, además de una distribución restringida a ambientes dulceacuícolas. Eugerres castroaguirrei se distingue de E. mexicanus mediante caracteres óseos diagnósticos como: proceso anterior del supraoccipital convexo, presencia de un foramen en el infraorbital 1, proceso ascendente del premaxilar desarrollado y con márgenes curvos, las placas faríngeas con dientes granulares desarreglados y los soportes de las aletas dorsal y anal reducidos. Asimismo, E. castroaguirrei se caracteriza por tener un cuerpo alargado y lateralmente comprimido cuyo grosor representa 37.6-58.5% de la longitud cefálica [LC]; la altura del cuerpo comprendida entre 33.8-42.1% de la longitud patrón [LP] y el diámetro ocular 23.3-31.6 % de la LC; además de 16 caracteres de tipo morfométrico: longitud de la segunda espina dorsal que representa 23.2-34.2% de la LP; segunda espina dorsal que cuando esta plegada se extiende hasta la base del tercer y cuarto radio dorsal; longitud de la segunda espina anal que comprende 11.1-20.6% de la LP; segunda espina anal que plegada se extiende hasta la base del tercer y cuarto radio anal, aunque no alcanza la porción distal del último radio anal; y la longitud de la espina de la aleta pélvica que comprende 49.7-65.0% de la longitud del primer radio pélvico.

Candida bucal en niños mexicanos con VIH/sida, desnutrición o marginación social / Oral candida in Mexican children with malnutrition, social marginalization, or HIV/AIDS

OBJETIVO: Determinar la frecuencia de Candida en cavidad bucal de niños con riesgo de desarrollar infecciones oportunistas y establecer si existe asociación entre la frecuencia de esta colonización bucal y tres tipos de población en riesgo. MÉTODOS: Se estudiaron cuatro grupos de población infantil de México: grupo VIH/sida bajo terapia antirretroviral altamente activa (TAAA) (35 niñas y 25 niños); grupo desnutrición (26 niñas y 29 niños); grupo tarahumara (37 niñas y 20 niños), una de las poblaciones étnicas más pobres del país, y grupo control (8 niñas y 21 niños aparentemente sanos). Los niños con VIH/sida fueron inmunológica y virológicamente clasificados según los criterios de EC-Clearinghouse, mientras que la desnutrición fue determinada a través del índice peso/talla de la Organización Mundial de la Salud. Se tomó una muestra de la mucosa bucal con hisopo estéril, que fue incubada en agar dextrosa Sabouraud y en CHROMagar-Candida®. Las especies de Candida se confirmaron con la prueba API ID32C. RESULTADOS: Los grupos VIH/sida y desnutrición mostraron la frecuencia más alta de Candida spp. (51,7 por ciento y 38,2 por ciento, respectivamente) mientras que el grupo tarahumara presenta una frecuencia semejante a la del grupo control (17,5 por ciento vs 10,3 por ciento). Respecto a las especies de Candida, el grupo desnutrición mostró la mayor diversidad: C. albicans, C. tropicalis, C. krusei y C. glabrata. CONCLUSIONES: Los infantes con inmunodeficiencia y con desnutrición requieren de estrategias diseñadas para disminuir la colonización bucal candidal y disminuir el riesgo de infecciones oportunistas.

OBJECTIVE: Determine the frequency of candida in the oral cavity of children with a risk of developing opportunistic infections, and establish if there is an association between the frequency of this oral colonization and three categories of at-risk populations. METHODS: Four infant population groups in Mexico were studied: an HIV/AIDS group undergoing highly active antiretroviral therapy (35 girls and 25 boys); a malnourished group (26 girls and 29 boys); a group from the Tarahumara indigenous people, one of the poorest ethnic populations in the country (37 girls and 20 boys); and a control group (8 girls and 21 boys in apparently good health). The children with HIV/AIDS were immunologically and virologically classified according to the EC Clearinghouse criteria, while malnutrition was determined through the World Health Organization's weight/height index. A sample of oral mucosa was taken with a sterile swab, which was incubated in Sabouraud dextrose agar and in Candida CHROMagar®. The species of candida were confirmed through the API ID32C test. RESULTS: The HIV/AIDS and malnutrition groups showed the higher frequency of Candida spps (51.7 percent and 38.2 percent, respectively), while the frequency level in the Tarahumara group was similar to that of the control group (17.5 percent versus 10.3 percent). With regard to the species of candida, the malnutrition group had the greatest diversity: C. albicans, C. tropical, C. krusei, and C. glabrata. CONCLUSIONS: The children with HIV/AIDS and malnutrition require strategies designed to reduce oral candidal colonization and reduce the risk of opportunistic infections.

Ictiofauna de los humedales del río San Pedro, Balancán, Tabasco, México

Ichthyofauna from wetlands of San Pedro, Balancán, Tabasco, México. San Pedro River’s wetlands sustain trophic nets in the fluvial system, due to the high habitat availability, and space and temporal variations. In order to describe the relationship between environmental parameters and ichthyofauna, this study evaluated fish assemblages composition, distribution, abundance, density, biomass, richness species, diversity and equitability in the wetlands. Sampling considered three different sites and climatic seasons (dry, rainy and cold fronts). The physical and chemical parameters considered were dissolved oxygen, temperature, pH, water transparency and the depth. Fishes were caught with a shrimp net, after six minutes towings and were identified afterwards. A total of 1 049 organisms of 25 fish species were caught, two of which were exotic species: Oreochromis niloticus and Parachromis managuense. A total of 23 species were found at site I (with the highest density 0.23ind./m²), 17 at site II (0.23ind./m²) and 14 at site III (0.12ind./m²). The dry season had the highest species number with 21 species, followed by the rainy season with 17 species, and the cold season with five species. Similarly, the highest biomass (8.30g/m²) was found in dry season, followed by the rainy (2.16g/m²) and the cold seasons (0.03g/m²). Considering seasons, highest density was found during the dry (0.436ind./m²), followed by the rainy (0.213ind./m²) and the cold (0.023ind./m²) seasons. The dominant density species during the study period, according to the quadrants graphic of Olmstead-Tukey were: Petenia splendida, Vieja heterospila, Vieja synspila, Dorosoma petenense and Astyanax aeneus. There were significant differences in the species richness among sites. Temperature, depth and transparency showed differences among the seasons. The canonical correspondence analysis indicated that fish distribution was governed by environmental parameters during all seasons. In terms of fish abundance and composition, environmental parameters play an important role showing spatial and temporal differences in the ecosystem, this could be explained with the fact that most of young fishes have a movement behavior to the wetlands, searching refuge and feed during the dry season. Considering the diversity indexes variation, it may be concluded that San Pedro River’s wetlands correspond to a system where the ichthyofauna composition fluctuates spatial and seasonally. Rev. Biol. Trop. 59 (2): 693-708. Epub 2011 June 01.

Los humedales de San Pedro sostienen redes tróficas del sistema fluvial debido a la alta disponibilidad de hábitats y a sus variaciones espacio-temporales. En esta investigación se estudió la composición, densidad y biomasa de la ictiofauna de los humedales; se capturaron 1 049 organismos de 25 especies, dos son exóticas: Oreochromis niloticus y Parachromis managuense. Con 23 especies capturadas en el sitio I, 17 en el II y 14 en el III. En la época de secas se obtuvo mayor riqueza con 21 especies, lluvias con 17 y cinco en nortes. La mayor densidad se mostró en el sitio II (0.23ind./m²), seguido de los sitios I y III (0.12, 0.12ind./m²). La mayor biomasa fue en secas (8.30g/m²), seguida de lluvias (2.1g/m²) y por último nortes (0.01g/m²). La mayor densidad se mostró en secas (0.43ind./m²) y la mínima en nortes (0.023ind./m²). Las especies dominantes en densidad según el diagrama Olmstead-Tukey fueron: Petenia splendida, Vieja heterospila, Vieja synspila, Dorosoma petenense y Astyanax aeneus. Por lo tanto, existieron diferencias significativas en los parámetros ecológicos y ambientales. Al considerar la variación en la riqueza podemos concluir que los humedales del río San Pedro, es un sistema donde la composición de la ictiofauna responde a las fluctuaciones espaciales y temporales.

Ictiofauna de sistemas cárstico-palustres con impacto antrópico: los petenes de Campeche, México

Ichthyofauna of karstic wetlands under anthropic impact: the "petenes" of Campeche, Mexico. "Petenes" are small springs and associated streams that drain into wetlands near the coast in karstic areas. We studied composition, distribution, and abundance of the ichthyofauna in Los Petenes region (northwest Campeche). Two petenes displaying different degrees and types of anthropic impact were selected, Hampolol and El Remate. Hampolol has a smaller area but a longer derived stream; it is located within a protected area, but has been invaded by tilapia. El Remate is a popular spa, with no tilapia; it has a larger area but a shorter derived stream. At each "petén", several sites in the main spring, the associated stream, and secondary (temporary) springs were sampled in the rainy and dry seasons. Fishing gear was variable (throw net, gill net, small and large seine nets), but effort was uniform. We recorded temperature, dissolved oxygen, salinity, and depth at each site and season; also, we noted the different types and intensities of anthropic impact (channelization, presence of exotic species, recreational use, etc.) at each petén. We compared the petenes in terms of their environmental quality and fish fauna (composition, distribution, abundance, biomass); we also tested for effects of season and site within each petén. The study found 27 species of fishes, included in 18 genera and eight families, 24 species in Hampolol and 20 in El Remate. The geographical range of ‘Cichlasoma’ salvini, Rivulus tenuis, Phallichthys fairweatheri, Xiphophorus hellerii, and X. maculatus is extended. The dominant species in both seasons was Astyanax (probable hybrids A. aeneus × altior at Hampolol, pure A. altior at El Remate), which contributed most of the abundance and biomass, together with Vieja synspila and Poecilia velifera. A significantly greater overall diversity (H’n=3.31) was recorded in Hampolol compared to El Remate (H’n=2.10). Cluster analysis of sites by species presence allowed distinction of two groupings within each petén: permanent waters (i.e., main spring, stream) vs. temporary sites (secondary springs, which dry out in winter). Environmental parameters (except salinity) presented significant differences by site and season; a canonical correspondence analysis indicated that the distribution of fish assemblages was influenced by the environmental parameters in both seasons. In terms of composition, historical factors play a role in the differences between the fish assemblages of the two petenes, especially concerning the presence of Astyanax hybrids and Xiphophorus spp. in the southern petén (Hampolol) and Poecilia velifera in the northern petén (El Remate). Rev. Biol. Trop. 57 (1-2): 141-157. Epub 2009 June 30.

Los petenes son pequeños manantiales y arroyos asociados que drenan a sistemas palustres en áreas cársticas costeras. Se estudió la composición, distribución y abundancia de la ictiofauna en dos petenes del noroeste de Campeche, en el manantial principal, el arroyo asociado, y pequeños ojos de agua secundarios (temporales), en dos épocas del año. Se registraron variables ambientales y tipos de impacto antrópico en cada petén. Se encontraron en total 27 especies de peces, con extensiones de ámbito de ‘Cichlasoma’ salvini, Rivulus tenuis, Phallichthys fairweatheri, Xiphophorus hellerii y X. maculatus. La especie dominante en ambas épocas fue Astyanax (probables híbridos A. aeneus × altior en Hampolol, A. altior en El Remate). Hubo diferencia significativa en diversidad entre ambos petenes. El análisis de conglomerados diferenció dos agrupaciones dentro de cada petén: aguas permanentes y sitios temporales. Las variables ambientales (excepto salinidad) presentaron diferencias significativas por sitio y época; un análisis de correspondencia canónica indicó que la distribución de los conjuntos de peces tuvo influencia de las variables ambientales en ambas temporadas. En términos de composición, los factores históricos juegan un papel en las diferencias ictiológicas entre ambos petenes, sobre todo por lo que concierne a la presencia de híbridos de Astyanax, así como Xiphophorus hellerii en el petén del sur (Hampolol) y de Poecilia velifera en el petén del norte (El Remate).